Reproduction of Organisms Chapter Resources for Differentiated Instruction Title Page
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Reproduction of Organisms Chapter Resources for Differentiated Instruction Title Page
Chapter Resources for Differentiated Instruction Reproduction of Organisms Title Page Lesson 1 Lesson 2 Level Get Ready to Read 1 all students Quick Vocabulary 3 all students Student Lab Safety Form 5 all students Launch Lab 8 28 all students Content Vocabulary ELL 9 29 all students Lesson Outline ELL 10 30 all students MiniLab 12 32 all students Content Practice A 13 33 AL OL BL Content Practice B 14 34 AL OL BL Language Arts Support 15 all students Math Skills 17 all students School to Home 18 35 Key Concept Builders 19 36 Enrichment 23 40 Challenge 24 41 AL OL BL Lesson Quiz A 25 42 AL OL BL Lesson Quiz B 26 43 AL OL BL all students AL OL BL all students Lab A 44–46 AL OL BL Lab B 47–49 AL OL BL Lab C 50 AL OL BL Chapter Key Concepts Builder 51 AL OL BL Chapter Test A 52–54 AL OL BL Chapter Test B 55–57 AL OL BL Chapter Test C 58–60 AL OL BL Answers (with Lesson Outlines) AL Approaching Level T2–T13 OL On Level BL Beyond Level ELL English-Language Learner Teacher evaluation will determine which activities to use or modify to meet any ELL student’s proficiency level. Copyright © by The McGraw-Hill Companies, Inc. All rights reserved. Permission is granted to reproduce the material contained herein on the condition that such materials be reproduced only for classroom use; be provided to students, teachers, and families without charge; and be used solely in conjunction with the Glencoe Middle School Science program. Any other reproduction, for sale or other use, is expressly prohibited. Send all inquiries to: Glencoe/McGraw-Hill 8787 Orion Place Columbus, OH 43240-4027 ISBN: 978-0-07-891455-3 MHID: 0-07-891455-8 Printed in the United States of America. 1 2 3 4 5 6 7 8 9 10 HES 15 14 13 12 11 10 To The Teacher This book contains reproducible pages that support the Student Edition. Descriptions and frequencies of these resources are listed in the table that follows. Title Get Ready to Read: What do you think? Frequency Appropriate For Overview Using the Get Ready to Read anticipation guide in the Student Edition? This page matches the 1/Chapter anticipation guide in the Student Edition. Students can complete this at the beginning of a chapter and check their responses at the end. all students Need some options to preteach vocabulary and help students with vocabulary development ? By Quick Vocabulary 1/Chapter folding the Quick Vocabulary sheet in half, students will have an easy reference tool. Lesson vocabulary, along with academic vocabulary, review vocabulary, or multiple-meaning words, are listed and defined. Students can add other words that they need to remember as well. all students Need a standard lab safety form? Each FastFile Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Student Lab Safety Form Launch Lab Content Vocabulary* Lesson Outline* MiniLab 1/Chapter includes this form that students can complete prior to each lab. Students indicate that they understand all aspects of the lab. There is a place for the student and you to sign it. 1/Lesson Want a lab recording page for Student Edition Launch Labs ? Each recording page matches the 1/Lesson Want to help students who need more vocabulary practice? Content Vocabulary pages provide review and Student Edition Launch Labs, so students do not need to use their textbooks in the lab. reinforcement activities. Use these pages to help students master content terms. all students all students all students Want an outline of the chapter for a substitute teacher, for absent students, or for students to use for review ? Lesson outlines follow the head and 1/Lesson 1/Lesson AL Approaching Level subhead structure of the Lesson, emphasizing the major content objectives. They can be used in many ways. In addition to those listed above, they can help you organize teaching notes and accompany student reading. Want a lab recording page for Student Edition MiniLabs ? This recording page matches the Student Edition MiniLab, so students do not need to use their textbooks in the lab. OL On Level BL Beyond Level all students all students * ELL English-Language Learner Teacher evaluation will determine which activities to use or modify to meet any ELL student’s proficiency level. Reproduction of Organisms iii Title Frequency Appropriate For Overview Need more options for content review? Content Content Practice (Leveled) Practice A is designed to help students who have difficulties learning and understanding the vocabulary and Key Concepts of each lesson: 1/Lesson • Form A—helps struggling students grasp lesson content AL AL AL • Form B—provides on-level and beyond-level reinforcement of lesson content AL OL BL Looking for a way to help students build reading and writing skills in science? Language Arts Language Arts Support 1/Chapter Math Skills 1/Chapter all students Support pages provide practice using vocabulary, language structure clues, and writing skills with science content. Want help for students who need to practice math skills ? This page provides additional practice all students of the Math Skill in the Student Edition. School to Home Enrichment all students for a home-learning partner to help a student better understand the Big Idea of a chapter. Have students who need more practice with Key Concepts ? Key Concept Builders present the content 4/Lesson 1/Lesson in a context different from the Student Edition. These pages can be used whenever a student is struggling with any of the lesson’s Key Concepts. AL Looking for ways to help students to broaden their understanding of lesson concepts ? Use Enrichment AL AL all students pages to further explore information and Key Concepts introduced in a lesson. Want to motivate the independent learner ? The Challenge 1/Lesson Challenge activity extends information in the Student Edition and challenges a student’s abilities. The activity can be completed in class or at home. AL AL BL OL BL Need options to evaluate students after each lesson? These quizzes are developed around the Key Lesson Quiz (Leveled) Concepts of a lesson: 1/Lesson AL Approaching Level • Quiz A—provides more guided questions AL • Quiz B—provides more short-answer and completion questions AL OL On Level BL Beyond Level * ELL English-Language Learner Teacher evaluation will determine which activities to use or modify to meet any ELL student’s proficiency level. iv Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Key Concept Builders 1/Lesson Looking for a way to help students with the content ? The School to Home page provides support Title Frequency Appropriate For Overview Need a lab recording page for the Skill Practice? Skill Practice 1/Chapter This corresponds to the Skill Practice in the Student Edition. Write-on lines are included for answers. Tables/ charts/graphs are included for recording observations, or space is provided for drawing tables/charts/graphs. Students do not need to use their textbooks in the lab. all students Want leveled lab recording pages for the Lab in the Student Edition? These pages provide leveled versions of the Student Edition Lab. Write-on lines are included for answers. Tables/charts/graphs are often included for recording observations, or space is provided for creating tables/charts/graphs: Lab (Leveled) Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Chapter Key Concepts Builder 1/Chapter 1/Chapter • Version A—This version follows the student edition lab but each step of the procedure is broken down sentence by sentence. Included are check-off boxes that provide easier processing for struggling learners. AL AL AL • Version B—This version is the student edition lab. AL OL BL • Version C—This version is designed to be a challenge for independent learners. Students must complete version B before doing version C. AL AL BL AL AL AL • Version A—provides students with more guided questions AL AL AL • Version B—more short-answer and completion questions AL OL AL • Version C—challenges students with more difficult and open-ended questions AL AL BL Have students who need more practice with Key Concepts related to the Big Idea? This practice page is designed to reinforce chapter content for struggling students before they take the chapter test. Need options to assess each student according to his or her abilities ? These leveled chapter tests accommodate all students: Chapter Test (Leveled) 1/Chapter Teacher Pages AL Approaching Level Want all the answers in one place? These pages contain the answers for all the practice pages. OL On Level BL Beyond Level * ELL English-Language Learner Teacher evaluation will determine which activities to use or modify to meet any ELL student’s proficiency level. Reproduction of Organisms v Name Date Class Get Ready to Read Reproduction of Organisms What do you think? Before you read, decide if you agree or disagree with each of these statements. On the line before each statement, place an A if you agree or a D if you disagree. As you read this chapter, see if you change your mind about any of the statements. Before You Read Statements After You Read 1. Humans produce two types of cells: body cells and sex cells. 2. Environmental factors can cause variation among individuals. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 3. Two parents always produce the best offspring. 4. Cloning produces identical individuals from one cell. 5. All organisms have two parents. 6. Asexual reproduction occurs only in microorganisms. What have you learned? After you read each lesson, return to this worksheet to see if you have changed your mind about any of the statements related to that lesson. Place a C after each statement that is correct or an I for those that are incorrect. Reproduction of Organisms 1 Name Date Class Quick Vocabulary Lesson 1 Lesson 2 diploid describes a cell that has pairs asexual reproduction production of of chromosomes DNA genetic information in a cell egg female sex cell fertilization joining of an egg and sperm haploid describes a cell that has only one chromosome from each pair homologous chromosomes pairs of chromosomes—one inherited from each parent—that have genes for the same traits arranged in the same order meiosis process in which one Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. diploid cell divides to make haploid sex cells sexual reproduction production of offspring from the combination of genetic materials from two cells sperm male sex cell offspring by one parent without meiosis and fertilization budding asexual reproduction in which a new organism grows on the body of its parent cloning lab procedure that produces identical individuals from a cell or cells taken from an organism culture growing living tissue in a laboratory fission cell division in prokaryotes that forms two genetically identical cells potential possibility regeneration asexual reproduction in which a new organism grows from a piece of its parent vegetative reproduction asexual reproduction in which offspring grow from a part of a parent plant zygote new cell formed through fertilization Reproduction of Organisms 3 Student Lab/Activity Safety Form Teacher Approval Initials Date of Approval Student Name: Date: Lab/Activity Title: • Carefully read the entire lab and answer the following questions. • Return this completed and signed safety form to your teacher to initial before you begin the lab/activity. 1. Describe what you will be doing during this lab/activity. Ask your teacher any questions Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. you might have regarding the lab/activity. 2. Will you be working alone, with a partner, or with a group? (Circle one.) 3. What safety precautions should you take while doing this lab/activity? 4. Write any steps in the procedure, additional safety concerns, or lab safety symbols that you do not understand. Student Signature Reproduction of Organisms 5 Lesson 1 | Sexual Reproduction and Meiosis Student Labs and Activities Page Appropriate For: Launch Lab 8 all students Content Vocabulary ELL 9 all students Lesson Outline ELL 10 all students MiniLab 12 all students Content Practice A 13 AL AL AL Content Practice B 14 AL OL BL Language Arts Support 15 all students Math Skills 17 all students School to Home 18 all students Key Concept Builders 19 Enrichment 23 Challenge 24 AL AL BL Lesson Quiz A 25 AL AL AL Lesson Quiz B 26 AL OL BL AL AL AL all students Assessment Teacher Support Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers (with Lesson Outlines) AL Approaching Level T2 OL On Level BL Beyond Level ELL English-Language Learner Teacher evaluation will determine which activities to use or modify to meet any ELL student’s proficiency level. Reproduction of Organisms 7 Name Date Launch Lab Class LESSON 1: 15 minutes Why do offspring look different? Unless you’re an identical twin, you probably don’t look exactly like any siblings you might have. You might have differences in physical characteristics such as eye color, hair color, ear shape, or height. Why are there differences in the offspring from the same parents? Procedure 1. Read and complete a lab safety form. 2. Open the paper bag labeled Male Parent, and, without looking, remove three beads. Record the bead colors in your Science Journal, and replace the beads. 4. Repeat steps 2 and 3 for each member of the group. 5. After each member has recorded his or her bead colors, study the results. Each combination of male and female beads represents an offspring. 3. Open the paper bag labeled Female Parent and remove three beads. Record the bead colors and replace the beads. Think About This 1. Compare your group’s offspring to another group’s offspring. What similarities or differences do you observe? 3. 8 Key Concept Why might this type of reproduction be beneficial to an organism? Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 2. What caused any differences you observed? Explain. Name Date Class Content Vocabulary LESSON 1 Sexual Reproduction and Meiosis Directions: Explain the relationship between/among the terms in each group below. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Terms How are these terms related? egg, sperm 1. fertilization, zygote 2. diploid, haploid 3. fertilization, sexual reproduction, DNA 4. homologous chromosomes, diploid 5. DNA, meiosis, homologous chromosomes 6. meiosis, diploid, haploid 7. Reproduction of Organisms 9 Name Date Class Lesson Outline LESSON 1 Sexual Reproduction and Meiosis A. What is sexual reproduction? 1. produces an offspring when genetic materials from two different sex cells combine. a. The female sex cell, a(n) , forms in an ovary. b. The male sex cell, a(n) , forms in a testis. 2. During a process called , an egg cell and a sperm cell join together. The new cell that forms is called a(n) . B. Diploid Cells 1. Organisms that reproduce sexually make two kinds of cells— cells and sex cells. 2. Body cells are ; they have pairs of chromosomes. 3. If a zygote has too many or too few , it will not develop properly. 4. Different organisms have different 5. of chromosomes. C. Haploid Cells 1. Sex cells are ; they have only one chromosome from each pair of chromosomes. 2. In , one diploid cell divides and makes four haploid cells. D. The Phases of Meiosis 1. Meiosis involves two divisions of the nucleus and the . These divisions, known as meiosis I and meiosis II, result in four haploid cells. 2. During , the reproductive cell grows and duplicates its chromosomes. 3. During meiosis I, each pair of duplicated homologous chromosomes . 4. After meiosis I, the two cells formed during this stage go through a second division of the sister 10 and cytoplasm called meiosis II. During meiosis II, separate to produce four haploid cells. Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. are pairs of chromosomes that have genes for the same traits arranged in the same order. Name Date Class Lesson Outline continued E. Why is meiosis important? 1. Meiosis forms sex cells with the correct haploid number of . This maintains the correct number of chromosomes in organisms when sex cells join. 2. Meiosis creates genetic variation by producing cells. F. How do mitosis and meiosis differ? 1. During and cell division, a body cell and its nucleus divide once and produce two identical cells. 2. During , a reproductive cell and its nucleus divide twice and produce four cells––two pairs of identical haploid cells. G. Advantages of Sexual Reproduction 1. Sexual reproduction produces that have a new combination of DNA. This results in genetic individuals. among 2. Genetic variation gives individuals within a population slight differences that might be an advantage if the Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 3. changes. breeding has been used to develop desirable traits in plants and animals. H. Disadvantages of Sexual Reproduction 1. One disadvantage of sexual reproduction is that organisms have to grow and develop until they are mature enough to produce cells. 2. Another disadvantage is that searching for a mate takes time and energy and might expose individuals to predators, environmental conditions. Reproduction of Organisms , or harsh 11 Name Date MiniLab Class LESSON 1: 20 minutes How does one cell produce four cells? When a diploid cell goes through meiosis, it produces four haploid cells. How does this happen? Procedure 1. Read and complete a lab safety form. 2. Make a copy of the diagram by tracing circles around a jar lid on your paper. Label as shown. 3. Use chenille craft wires to make red and blue duplicated chromosomes Diploid cell 2.5 cm long and green and yellow duplicated chromosomes 1.5 cm long. Recall that a duplicated chromosome has two sister chromatids connected at the centromere. 4. Place the chromosomes in the diploid cell. 5. Move one long chromosome and one short chromosome into each of the middle cells. Meiosis I Meiosis II 6. Separate the two strands of the chromosomes, and place one strand into each of the haploid cells. Haploid cells 1. Describe What happened to the chromosomes during meiosis I? During meiosis II? 2. Think Critically Why are two haploid cells (sperm and egg) needed to form a zygote? 3. 12 Key Concept How does one cell form four cells during meiosis? Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Analyze and Conclude Name Date Class Content Practice A LESSON 1 Sexual Reproduction and Meiosis Directions: On the line before each definition, write the letter of the term that matches it correctly. Each term is used only once. 1. production of an offspring through the combination of egg and sperm A. diploid cell B. egg C. fertilization 2. female sex cell 3. male sex cell D. haploid cell E. homologous chromosomes F. meiosis 4. joining of egg and sperm 5. the cell formed by fertilization G. sexual reproduction H. sperm I. zygote 6. body cell or zygote, which has pairs Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. of chromosomes 7. male or female sex cell that has only one chromosome from each pair 8. process by which one diploid cell divides into four haploid cells 9. two chromosomes that have genes for the same traits in the same order Directions: On the line before each statement, write T if the statement is true or F if the statement is false. 10. Sexual reproduction produces offspring that is identical to the parents. 11. The nucleus divides in meiosis I and again in meiosis II. 12. During meiosis, the number of chromosomes in each cell stays the same. Reproduction of Organisms 13 Name Date Class Content Practice B LESSON 1 Sexual Reproduction and Meiosis Directions: Answer each question or respond to each statement on the lines provided. 1. Define sexual reproduction. 2. What are male and female sex cells, and where are they made? 3. Explain what a zygote is. Use the terms egg cell, sperm cell, and fertilization in your explanation. 5. Which process divides one diploid cell and makes four haploid cells? How many times does the nucleus divide during this process? 6. What are homologous chromosomes? 14 Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 4. Compare a diploid cell and a haploid cell. Include where each cell is located. Name Date Language Arts Support Class LESSON 1 Writing Activity: Revisions Learning the Skill Few people get everything right the first time. When you draw a picture, you probably erase and sketch it many times. A theater performance requires many rehearsals before it is ready for an audience. In a similar way, the writing process involves more than one draft. After you gather ideas, take notes, and develop an outline, you write a draft, which puts the ideas together. Then it is time to revise. Revision takes a piece of writing to the next level. During this step, you review your work to make sure your ideas will be clear to your readers. Multiple revisions are often necessary. It might help to think of revisions on four different levels: • Overall Structure—Readers can understand your writing more clearly if you combine related ideas. As you review your writing, circle each main point in a different color. Then underline each sentence that supports that point in the same color. If your paragraph contains marks of several different colors, move sentences to the paragraph they support. If you find sentences that are not circled or underlined, delete the sentence or use it in a new paragraph. • Paragraphs—Make sure the main idea in each paragraph is adequately supported. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Several types of sentences can support a main idea. Use the following list to evaluate the strength of each paragraph. If your review shows that an idea needs more support, add one of the sentence types from this list. Paragraph Number Supporting Sentences: Main Idea: Detail: Example: Fact: Quotation: • Sentences—Review your sentence patterns. Are your sentences mostly short or long? Do their beginnings vary, or do they start the same way? Some ways to add variety to your sentences include inserting a short sentence between two long ones; combining two sentences into one longer, compound sentence; changing the passive to the active tense to make the writing more vivid and concise. • Word Choice—Review your draft again, checking for repeated words or words that are too general. Highlight nouns, verbs, adjectives, and phrases you have used more than once. Then use a thesaurus to find alternate words. Highlight general words and replace them with more concise ones; for example, tree → oak; dog → beagle; red → crimson. Reproduction of Organisms 15 Name Date Language Arts Support Class LESSON 1 Writing Activity: Revisions Practicing the Skill Directions: Read the following draft. Then answer each question or respond to each statement on the lines provided. Meiosis is a special type of cell division that produces eggs and sperm for sexual reproduction. Mitosis is a different process by which cells divide. Meiosis is cell division that produces eggs or sperm from certain cells in an organism’s reproductive system. Meiosis is a process that only takes place in eukaryotes that reproduce sexually. Sexual reproduction only occurs among some organisms. 1. What is the main idea of the paragraph? 2. Which two sentences do not fit the main idea of the paragraph? What do you think the writer should do with these sentences? Explain why. Revise the sentence below to eliminate the repetition. Meiosis is cell division that produces eggs or sperm from certain cells in an organism’s reproductive system. 4. Look at the sentence you revised in question 3. Three sentences start with the words “Meiosis is.” Make an additional revision to the sentence above or another sentence to vary the sentence structure. Applying the Skill Directions: Review a piece of writing that you have worked on for this class. Evaluate it using the four levels of revisions outlined under Learning the Skill. Then use the suggested strategies to revise your draft. Exchange your revised paper with a partner to find out whether your ideas are clear. 16 Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 3. The phrase “cell division that produces eggs and sperm” appears twice in this paragraph. Name Date Class Math Skills LESSON 1 Use Proportions A proportion is an equation that shows that two ratios are equal. When two ratios form a proportion, the cross products are equal. In this example, the cross products are 2 × 10 and 4 × 5. 5 2 = ___ If __ , then 2 × 10 = 4 × 5. 10 4 If one of the numbers in a proportion is unknown, cross multiply to change the proportion to an equation. Then solve the equation for the unknown number. You know that 1 cell produces 2 daughter cells at the end of mitosis. How many daughter cells will be produced by 19 cells? Step 1 Use the information in the problem to write a proportion. 1 __ 2 19 = ___ n Step 2 Cross multiply to solve for the unknown number. 1 × n = 2 × 19 n = 38 Step 3 Use the solution to answer the question in the original problem situation. The 19 cells will produce 38 daughter cells. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Practice 1. If 7 cells go through mitosis, how many daughter cells will be produced? 3. The egg of a type of frog is 1.5 mm wide. If you place 12 eggs in a line, what is the length of the line from end to end? Reproduction of Organisms 2. If 47 sex cells go through meiosis, how many daughter cells will be produced? 4. For another type of frog, 3 eggs in a row measure 6 mm across. What is the length of a line of 12 eggs? 17 Name Date Class School to Home LESSON 1 Sexual Reproduction and Meiosis Directions: Use your textbook to answer each question. 1. The production of an offspring resulting from the combination of genetic materials of two different cells is called sexual reproduction. How is a zygote formed in sexual reproduction? 2. Diploid cells have pairs of chromosomes, whereas haploid cells have only one chromosome from each pair. Which cells are sex cells, diploid cells or haploid cells? 3. Meiosis and mitosis are similar processes in which an organism produces new cells. 4. Meiosis produces cells that are not genetically identical to the parent cell. What are the advantages and disadvantages of sexual reproduction? 18 Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. What are the differences between the processes of meiosis and mitosis? Name Date Class Key Concept Builder LESSON 1 Sexual Reproduction and Meiosis Key Concept What is sexual reproduction, and why is it beneficial? Directions: Work with a partner to answer each question or respond to each statement on the lines provided. 1. Name the type of reproduction that occurs when the genetic materials from two different cells combine to produce an offspring. 2. What are egg cells? 3. What are sperm cells? Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 4. Explain the relationship between fertilization and a zygote. 5. What happens to a zygote? 6. Compare the DNA of an offspring to the DNA of its parents. 7. Why do offspring from the same parents usually have a different set of traits? Reproduction of Organisms 19 Name Date Class Key Concept Builder LESSON 1 Sexual Reproduction and Meiosis Key Concept What is the order of the phases of meiosis, and what happens in each phase? Directions: On each line, write the term from the word bank that correctly completes each sentence. Some terms may be used more than once or not at all. diploid haploid homologous chromosomes meiosis mitosis sister chromatids 1. In meiosis, one cell divides to make four cells. 2. A cell has half the chromosomes of a cell. 3. A cell has pairs of chromosomes. 4. Pairs of chromosomes that are not identical but have genes for the same trait arranged in the same order are . has one chromosome from the mother and one chromosome from the father. 6. In 7. During , the two chromosomes are always identical. , two divisions of the nucleus and the cytoplasm occur. 8. When a cell duplicates one chromosome, two are formed. 9. During interphase of mitosis and meiosis, two are formed for each chromosome. 10. A reproductive cell goes through interphase before beginning I, but not before II. 11. Prophase I and Prophase II are stages in . 20 Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 5. Each pair of Name Date Class Key Concept Builder LESSON 1 Sexual Reproduction and Meiosis Key Concept What is the order of the phases of meiosis, and what happens in each phase? Directions: Work with a partner. On each line, write the term or phrase that correctly completes each sentence. Meiosis I Phase Prophase I Description 1. Chromosomes that are duplicated during remain sister chromatids. 2. join and form pairs. 3. The membrane surrounding the nucleus Metaphase I apart. 4. Homologous chromosome pairs align along the of the cell. 5. Anaphase I fibers attach to each pair. 6. Pairs of duplicated and are pulled toward opposite ends of the cell. chromosomes separate 7. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Telophase I stay together. 8. A nuclear membrane forms around each group of chromosomes. The cytoplasm divides forming daughter cells. 9. remain together. Meiosis II Phase Prophase II Description 10. do not duplicate. breaks apart. Metaphase II 11. Sister chromatids along the middle of the cell. Anaphase II 12. Sister chromatids of each duplicated chromosome are and move to Telophase II . 13. A nuclear membrane forms around each set of chromatids, which are again called 14. The cytoplasm divides, and 15. Each cell has as the original cell. Reproduction of Organisms . cells form. the number of chromosomes 21 Name Date Class Key Concept Builder LESSON 1 Sexual Reproduction and Meiosis Key Concept Why is meiosis important? Directions: Answer each question on the lines provided. 1. If a male organism has 40 chromosomes in each body cell, how many chromosomes does a female of the same species have in each body cell? 2. How many homologous pairs of chromosomes does the male have? 3. How many chromosomes would be in a sperm cell and in an egg cell? 4. How many chromosomes would be in an offspring? 5. How many pairs of homologous chromosomes would be in an offspring? 6. What is the difference between a diploid cell and a haploid cell? diploid, haploid, fertilized egg, and sex cells in your answer. 22 Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 7. How does meiosis help maintain diploid cells in offspring? Use the terms chromosomes, Name Date Class Enrichment LESSON 1 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Rescuing Native Plants Most North American food crops are not native. Instead, they were brought to America by European settlers. Many of these crops are not resistant to American diseases and pests—but native plants often are. That’s why native plants play an important role in growing healthy food crops. drier and hotter conditions than most other species of rice. Such traits are especially useful in areas that experience droughts, or extended periods of belowaverage rainfall. The traits might also be needed if Earth’s surface temperatures continue to rise on a global level. Breeding with Native Plants Benefits Versus Costs Scientists can breed native plants with crop plants to produce hardier plants. For example, if potatoes are threatened by disease, scientists can cross potatoes with a native plant that has traits that make it naturally disease resistant. Using the same technique, scientists can produce plants that are more resistant to pests. Improved resistance has environmental benefits as well, because farmers can use less chemical pesticide. Some native plants are better able to withstand the climatic conditions in different parts of America. For example, a wild rice plant grows on the banks of a single stream in Texas. This plant, which is in danger of becoming extinct, can survive Most scientists agree that native plants should be preserved. They point out that the health of the planet depends on a high level of species diversity. In addition, some native plants might have unknown medicinal or commercial value; if they become extinct, these benefits are lost forever. However, other experts point out that the cost of saving each native plant is very high. They argue that society must determine the potential value of each species before paying the high cost of saving that species. About 700 native plants in the United States are endangered, or at risk of becoming extinct. That’s nearly onefourth of all native plants in the country. Applying Critical-Thinking Skills Directions: Answer each question or respond to each statement. 1. Infer Why are native plants often resistant to the diseases and pests in their native land? 2. Weigh Do you think that all native plants should be preserved, or should only those plants that have value for people be preserved? Explain. Reproduction of Organisms 23 Name Challenge Date Class LESSON 1 Sequencing Meiosis The diagrams show the stages of meiosis in scrambled order. To the left of each diagram, label and sequence the stages in the correct order. To the right of each diagram, include a brief description of what happens during each stage. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 24 Reproduction of Organisms Name Date Class Lesson Quiz A LESSON 1 Sexual Reproduction and Meiosis Matching Directions: On the line before each definition, write the letter of the term that matches it correctly. Each term is used only once. Matching Set 1 1. when one diploid cell divides to make four haploid cells 2. when an egg cell and a sperm cell join A. homologous B. fertilization C. meiosis 3. pair of chromosomes in which one chromosome is inherited from each parent Matching Set 2 4. new cell formed by the joining of a sperm and an egg 5. cells going through a second division of the D. meiosis II E. sexual reproduction F. zygote nucleus Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 6. when the genetic materials from two different cells combine to produce a new organism Multiple Choice Directions: On the line before each question, write the letter of the correct answer. 7. Which phase comes after telophase I in meiosis? A. interphase B. prophase II C. metaphase I 8. Why is meiosis important? A. It produces sex cells. B. It produces diploid cells. C. It produces chromosomes. Reproduction of Organisms 25 Name Date Class Lesson Quiz B LESSON 1 Sexual Reproduction and Meiosis Completion Directions: On each line, write the term that correctly completes each sentence. 1. During 2. , one diploid cell divides to make four haploid cells. is the joining of an egg cell and a sperm cell. 3. The production of an offspring that results when the genetic materials from two different cells combine is called . 4. A new cell formed by the joining of a sperm and an egg is called a(n) . 5. During meiosis II, the cells formed during this stage go through a second division of the and the cytoplasm. 6. In a pair of , one chromosome is inherited from each parent. Short Answer Directions: Respond to each statement on the lines provided. 7. Compare and contrast the events of meiosis I with the events of meiosis II. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 8. Explain the importance of meiosis. 26 Reproduction of Organisms Lesson 2 | Asexual Reproduction Student Labs and Activities Page Appropriate For: Launch Lab 28 all students Content Vocabulary ELL 29 all students Lesson Outline ELL 30 all students MiniLab 32 all students Content Practice A 33 AL AL AL Content Practice B 34 AL OL BL School to Home 35 Key Concept Builders 36 Enrichment 40 Challenge 41 AL AL BL Lab A 44 AL AL AL Lab B 47 AL OL BL Lab C 50 AL AL BL Chapter Key Concepts Builder 51 AL AL AL Lesson Quiz A 42 AL AL AL Lesson Quiz B 43 AL OL BL Chapter Test A 52 AL AL AL Chapter Test B 55 AL OL AL Chapter Test C 58 AL AL BL all students AL AL AL all students Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Assessment Teacher Support Answers (with Lesson Outlines) AL Approaching Level T4 OL On Level BL Beyond Level ELL English-Language Learner Teacher evaluation will determine which activities to use or modify to meet any ELL student’s proficiency level. Reproduction of Organisms 27 Name Date Launch Lab Class LESSON 2: 20 minutes How do yeast reproduce? Some organisms can produce offspring without meiosis or fertilization. You can observe this process when you add sugar and warm water to dried yeast. Procedure 1. Read and complete a lab safety form. 2. Pour 125 mL of water into a beaker. The water should be at a temperature of 34°C. 3. Add 5 g of sugar and 5 g of yeast to the water. Stir slightly. Record your observations after 5 minutes in your Science Journal. 4. Using a dropper, put a drop of the yeast solution on a microscope slide. Place a coverslip over the drop. 5. View the yeast solution under a microscope. Draw what you see in your Science Journal. Think About This 1. What evidence did you observe that yeast reproduce? 28 Key Concept How do you think this process differs from sexual reproduction? Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 2. Name Date Class Content Vocabulary LESSON 2 Asexual Reproduction Directions: Write the correct term in the boxes to the right of each definition. Then unscramble the letters from the shaded boxes to spell an eighth term. asexual reproduction budding cloning culture fission potential regeneration vegetative reproduction 1. cell division in prokaryotes 2. a type of asexual reproduction in which a new organism grows on the body of the parent organism 3. the process of growing living tissue in a laboratory 4. possibility Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 5. asexual reproduction in which a new organism grows from a piece of its parent 6. the production of offspring by one parent without meiosis and fertilization 7. asexual reproduction by plants 8. When they are unscrambled, the letters in the shaded boxes spell , which is the process of making identical individuals. Reproduction of Organisms 29 Name Date Class Lesson Outline LESSON 2 Asexual Reproduction A. What is asexual reproduction? 1. In , one parent organism produces offspring without meiosis and fertilization. 2. Because the offspring of asexual reproduction inherit all their DNA from one parent, they are genetically parent. to each other and their B. Types of Asexual Reproduction 1. Cell division in prokaryotes is known as . 2. During fission, DNA is and the cell splits to form two identical offspring. The original cell no longer exists. 3. Many unicellular reproduce by mitotic cell division. In this type of asexual reproduction, an organism forms two offspring through mitosis and 4. In . , a new organism grows on the body of its parent by mitosis and cell division. When the bud becomes enough, it can break from the parent and live on its own. occurs when an offspring grows from a piece of its parent. a. Sea stars, sea urchins, sea cucumbers, and planarians can through regeneration. b. Many animals can damaged or lost body parts. This is not reproduction; 6. are not produced. is a form of asexual reproduction in which offspring grow from a part of a parent plant. 7. is a type of asexual reproduction developed by scientists and performed in laboratories. It produces individuals from a cell or from a cluster of cells taken from a multicellular organism. 8. Using a cloning method called , plant growers and scientists can use a meristem to make a copy of a plant with desirable traits. 9. Because all of a clone’s come from one parent, the clone is a genetic copy of its parent. 30 Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 5. Name Date Class Lesson Outline continued 10. Asexual reproduction enables organisms to reproduce without a(n) . 11. Asexual reproduction also enables some organisms to rapidly produce a large number of . 12. Asexual reproduction produces offspring that are genetically identical to each other and to their . This results in minimal genetic within a population. 13. Genetic variation is important because it can give organisms a better chance of if the environment changes. 14. Genetic changes, called Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. , can occur and then be passed to offspring; this can affect the offspring’s ability to survive. Reproduction of Organisms 31 Name Date MiniLab Class LESSON 2: 15 minutes What parts of plants can grow? You probably know that plants can grow from seeds. But you might be surprised to learn that other parts of plants can grow and produce a new plant. Procedure 1. Carefully examine the photos of vegetative reproduction shown in your textbook. 2. Create a data chart in your Science Journal to record your observations. Identify which part of the plant (leaf, stem, etc.) would be used to grow a new plant. Analyze and Conclude 1. Explain How is the vegetative reproduction you observed a type of asexual reproduction? 2. Infer how farmers or gardeners might use vegetative reproduction. 32 Key Concept Describe a method you might use to produce a new plant using vegetative reproduction. Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 3. Name Date Class Content Practice A LESSON 2 Asexual Reproduction Directions: On each line, write the term from the word bank that correctly completes each sentence. Each term is used only once. asexual reproduction budding cloning fission genetically identical mitotic cell division nucleus regeneration tissue culture vegetative reproduction 1. In all types of , one parent organism produces offspring without meiosis or fertilization. 2. When offspring inherit all of their DNA from one parent, they are . 3. Cell division in prokaryotes is known as . 4. Many unicellular eukaryotes reproduce by dividing into two offspring through mitosis Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. and cell division. This form of reproduction is known as 5. In . , a new organism grows on the body of its parent by mitosis and cell division. 6. In animal , a new animal grows from a piece of its parent. 7. A form of asexual reproduction in which offspring grow from a part of a parent plant is called . 8. A type of asexual reproduction that produces identical individuals from a cell or cluster of cells taken from a multicellular organism is called . 9. Some plants can be cloned from just a few cells using a technique that takes a(n) . 10. Some animals have been cloned using the from a cell in one parent. Reproduction of Organisms 33 Name Date Class Content Practice B LESSON 2 Asexual Reproduction Directions: On the line before each statement, write T if the statement is true or F if the statement is false. If the statement is false, change the underlined word(s) to make it true. Write your changes on the lines provided. 1. Meiosis and fertilization are not a part of asexual reproduction. 2. A hydra grows a new hydra on its body using a form of asexual reproduction called budding. 3. Cloning produces identical individuals from a cell or cluster of cells taken from a unicellular organism. 4. In all types of sexual reproduction, offspring are produced by one parent organism. 5. Some animals can grow a new limb in a process called regeneration. plant is called vegetative reproduction. 7. A disadvantage of asexual reproduction is that the organisms can reproduce without using the time and energy to find a mate. 8. Cell division in prokaryotes is known as mitotic cell division. 9. Some animals have been cloned using the cytoplasm from a cell in one parent. 10. Many unicellular eukaryotes reproduce by dividing into two offspring through mitosis and cell division. This form of reproduction is known as mitotic cell division. 34 Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 6. A form of asexual reproduction in which offspring grow from a part of a parent Name Date School to Home Class LESSON 2 Asexual Reproduction Did you know? Although most animals do not practice asexual reproduction, a few do. Flatworms, a parasite in humans and other animals, can reproduce sexually or asexually. In this activity, you will design an investigation of any type of asexual reproduction. 1. Write a Question Think about what interests you in the different ways organisms can reproduce asexually. Write a question that will be the basis of your investigation. 2. Form a Hypothesis Based on what you know about asexual reproduction, what do you think the answer to your investigation question will be? Write your hypothesis. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 3. Develop a Method Decide the best method to use to answer your investigation question. What will you look for? Write your method. 4. Collect Data How will you measure the results? Describe your data-collection plan. 5. Plan for Problems Describe how you will deal with a potential problem with the investigation. Reproduction of Organisms 35 Name Date Class Key Concept Builder LESSON 2 Asexual Reproduction Key Concept What is asexual reproduction, and why is it beneficial? Directions: Respond to each statement on the lines provided. 1. Define asexual reproduction. 2. Explain why the offspring of asexual reproduction are genetically identical to each other and to their parent. 4. Explain how plant cloning is useful for farmers and scientists. 5. Identify the two main advantages for organisms that reproduce asexually. 36 Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 3. List six types of asexual reproduction. Name Date Class Key Concept Builder LESSON 2 Asexual Reproduction Key Concept How do the types of asexual reproduction differ? Directions: Complete the Venn diagram by writing features of fission on the left and mitotic cell division on the right. Write what they have in common in the center. 1. Fission 2. Both 3. Mitotic cell division Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Directions: Respond to each statement in the space provided. 4. Draw a picture showing a hydra budding. 5. Explain how budding can produce new organisms. 6. Draw a picture showing a planarian forming two offspring by animal regeneration. 7. Explain how animal regeneration can produce new organisms. 8. Draw a picture showing vegetative reproduction. 9. Explain how vegetative reproduction can produce new organisms. Reproduction of Organisms 37 Name Date Key Concept Builder Class LESSON 2 Asexual Reproduction Key Concept How do the types of asexual reproduction differ? Directions: Put a check mark on the line before each phrase that applies to cloning. 1. a form of sexual reproduction 2. produces genetically identical offspring 3. a technique developed by scientists 4. occurs in nature 5. produces offspring from a cell or a cluster of cells 6. used by unicellular organisms Directions: Place your response on the lines provided. 7. Based on your check marks above, write a paragraph that describes what cloning is. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 38 Reproduction of Organisms Name Date Key Concept Builder Class LESSON 2 Asexual Reproduction Key Concept How do the types of asexual reproduction differ? Directions: Work with a partner to answer each question on the lines provided. 1. How has the definition of cloning changed from the past to today? 2. Which type of asexual reproduction in plants is most similar to animal regeneration? Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Explain your answer. 3. If a sea star grows a new arm, is the regeneration a form of asexual reproduction? Explain your answer. 4. Why is growing a new plant from cloning different from vegetative reproduction? Reproduction of Organisms 39 Name Date Enrichment Class LESSON 2 Clone from the past? Cloning is a type of asexual reproduction that produces offspring from cells taken from a multicellular organism. Scientists have successfully cloned sheep. But can they produce a clone from an animal that died more than 23,000 years ago? temperatures that preserved the fossil also severely damaged the chromosomes in the mammoth’s body cells. Extreme cold had burst the cells. There was not enough DNA to clone the mammoth. New Hope The Woolly Mammoth In 2007, scientists discovered yet another mammoth in Siberia. “It’s a lovely little baby mammoth indeed, found in perfect condition,” said Alexei Tikhonov, deputy director of the Russian Academy of Science’s Zoological Institute. “This specimen may provide unique material allowing us to ultimately decipher the genetic makeup of the mammoth.” The baby mammoth, named Lyuba, once again raised hopes of cloning a mammoth. Dr. Ian Barnes of the University of London stated that he now believes a mammoth will be cloned in his lifetime. Tikhonov, however, points out that whole cells are needed for cloning. He is doubtful that Lyuba’s cells, which endured freezing temperatures, are intact. Other scientists note that, even if a mammoth is cloned, its natural habitat no longer exists. They argue that it would be better to spend time and resources preserving endangered species that are now in danger of extinction. Applying Critical-Thinking Skills Directions: Respond to each statement. 1. Explain the main obstacle to cloning the woolly mammoth. 2. Deduce the information that scientists might learn—other than genetic makeup—by studying the remains of an extinct animal. 40 Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. In 1999, a helicopter pulled an 18-metric-ton block of ice and soil from the ground in northern Siberia. Inside that huge block were the frozen remains of a woolly mammoth. Other mammoths had been discovered before. But most were fossilized bones and tusks. This mammoth, called the Zharkov mammoth, was thought at first to be well preserved. Some of its skin, hair, and soft tissue appeared to be intact. Scientists hoped to clone the woolly mammoth by extracting DNA from its cells. Studies have shown that mammoths have a close genetic relationship with modern elephants. So the mammoth’s DNA would be placed in the egg cell of a female elephant. The elephant would serve as a substitute mother. Eventually, she would give birth to a live woolly mammoth. As the fossil was carefully thawed, however, scientists found that only a small fraction of its soft parts were intact. Further study showed that the same cold Name Date Challenge Class LESSON 2 Plant Reproduction As you have learned, plants can reproduce asexually. In the space below, design an experiment to grow a new plant using some type of asexual reproduction. 1. Decide which type of asexual reproduction you will investigate. 2. Form a hypothesis about how a new plant can be produced from a parent plant. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 3. Describe each step of your procedure. 4. List the materials you will use in your experiment. 5. Identify any safety measures you will take. 6. Perform the experiment with your teacher’s permission. 7. Summarize your results. Reproduction of Organisms 41 Name Date Class Lesson Quiz A LESSON 2 Asexual Reproduction Multiple Choice Directions: On the line before each question, write the letter of the correct answer. 1. Which process is NOT a form of asexual reproduction? A. fission B. meiosis C. budding 2. Which statement reflects a way in which asexual reproduction is beneficial? A. It results in genetic variation. B. It requires a lot of time and energy. C. Organisms can reproduce without a mate. Matching Directions: On the line before each definition, write the letter of the term that matches it correctly. Each term is used only once. Matching Set 1 3. prokaryotic cell division A. budding 4. offspring growing on the body of its parent B. fission C. regeneration Matching Set 2 6. one parent producing offspring without meiosis and fertilization 7. identical organisms growing from cells grown in a laboratory D. asexual reproduction E. vegetative reproduction F. cloning 8. offspring growing from part of a parent plant 42 Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 5. offspring growing from a piece of its parent Name Date Class Lesson Quiz B LESSON 2 Asexual Reproduction Completion Directions: On the line, write the term that correctly completes each sentence. 1. Prokaryotic cell division is called 2. . is a type of asexual reproduction that occurs when an offspring grows on the body of its parent by mitosis and cell division. 3. Animal occurs when an offspring grows from a piece of its parent. 4. The process in which one parent produces offspring without meiosis and fertilization is called . 5. The process of produces identical individuals in a laboratory from cells taken from a multicellular organism. 6. Vegetative reproduction occurs when an offspring grows from part of a parent . Short Answer Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Directions: Respond to each statement on the lines provided. 7. Write an example of asexual reproduction and an organism that uses it. 8. Explain one advantage of asexual reproduction. Reproduction of Organisms 43 Name Date Class Lab A 40 minutes Mitosis and Meiosis During cellular reproduction, many changes occur in the nucleus of cells involving the chromosomes. You could think about these changes as a set of choreographed moves like you would see in a dance. In this lab, you will act out the moves that chromosomes make during mitosis and meiosis in order to understand the steps that occur when cells reproduce. Ask a Question How do chromosomes change and move during mitosis and meiosis? Materials pool noodles Safety Make Observations 1. Read and complete a lab safety form. 2. Form a cell nucleus with four chromosomes represented by students holding four different colors of pool noodles. Other students play the part of the nuclear membrane and form a circle around the chromosomes. chromosome with two sister chromatids. 4. Perform the following steps of mitosis. a. During prophase, the nuclear membrane breaks apart, and the nucleolus disappears. b. In metaphase, duplicated chromosomes align in the middle of the cell. c. The sister chromatids separate in anaphase. d. In telophase, the nuclear membrane reforms around two daughter cells. 5. Repeat steps 2 and 3. Then perform the following steps of meiosis. a. In prophase I, the nuclear membrane breaks apart, the nucleolus disappears, and homologous chromosomes pair up. b. In metaphase I, homologous chromosomes line up along the center of the cell. c. During anaphase I, the pairs of homologous chromosomes separate. d. In telophase I, the nuclear membrane reforms. 44 Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 3. The chromosomes duplicate during interphase. Each chromosome is copied, creating a Name Date Class Lab A continued e. Each daughter cell now performs meiosis II independently. In prophase II, the nuclear membrane breaks down, and the nucleolus disappears. Remember to use scientific methods. f. During metaphase II, duplicated chromosomes Ask a Question align in the middle of the cell. Make Observations Form a Hypothesis g. Sister chromatids separate in anaphase II. Test your Hypothesis h. In telophase II, the nuclear membrane reforms. Analyze and Conclude Form a Hypothesis Communicate Results 6. Use your observations to form a hypothesis about the results of an error in meiosis. For example, you might explain the results of an error during anaphase I. Test Your Hypothesis Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 7. Perform meiosis again, incorporating the error you chose in step 6. 8. Compare the outcome to your hypothesis. Does your data support your hypothesis? If not, revise your hypothesis and repeat steps 6–8. Analyze and Conclude 9. Compare and Contrast How are mitosis and meiosis I similar? How are they different? 10. The Big Idea What is the difference between the chromosomes in cells at the beginning and the end of mitosis? At the beginning and end of meiosis? Reproduction of Organisms 45 Name Date Class Lab A continued 11. Critique How did performing cellular replications using pool noodles help you understand mitosis and meiosis? Communicate Your Results Create a chart of the changes and movements of chromosomes in each of the steps in meiosis and mitosis. Include colored drawings of chromosomes and remember to draw the cell membranes. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Lab Tips • Figure out where the boundaries of your cell are before you start. • Review the phases of mitosis and meiosis before beginning to act out how the chromosomes move during each process. 46 Reproduction of Organisms Name Date Class Lab B 40 minutes Mitosis and Meiosis During cellular reproduction, many changes occur in the nucleus of cells involving the chromosomes. You could think about these changes as a set of choreographed moves like you would see in a dance. In this lab, you will act out the moves that chromosomes make during mitosis and meiosis in order to understand the steps that occur when cells reproduce. Ask a Question How do chromosomes change and move during mitosis and meiosis? Materials pool noodles Safety Make Observations 1. Read and complete a lab safety form. 2. Form a cell nucleus with four chromosomes represented by students holding four different colors of noodles. Other students play the part of the nuclear membrane and form a circle around the chromosomes. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 3. The chromosomes duplicate during interphase. Each chromosome is joined by another chromosome of the same color, creating a double-stranded chromosome. 4. Perform mitosis. a. During prophase, the nuclear membrane breaks apart, and the nucleolus disappears. b. In metaphase, duplicated chromosomes align in the middle of the cell. c. The sister chromatids separate in anaphase. d. In telophase, the nuclear membrane reforms around two daughter cells. 5. Repeat steps 2 and 3. Perform meiosis. a. In prophase I, the nuclear membrane breaks apart, the nucleolus disappears, and homologous chromosomes pair up. b. In metaphase I, homologous chromosomes line up along the center of the cell. c. During anaphase I, the pairs of homologous chromosomes separate. d. In telophase I, the nuclear membrane reforms. e. Each daughter cell now performs meiosis II independently. In prophase II, the nuclear membrane breaks down, and the nucleolus disappears. f. During metaphase II, duplicated chromosomes align in the middle of the cell. Reproduction of Organisms 47 Name Date Class Lab B continued g. Sister chromatids separate in anaphase II. h. In telophase II, the nuclear membrane reforms. Form a Hypothesis 6. Use your observations to form a hypothesis about the results of an error in meiosis. For example, you might explain the results of an error during anaphase I. Remember to use scientific methods. Make Observations Ask a Question Form a Hypothesis Test your Hypothesis Analyze and Conclude Communicate Results Test Your Hypothesis 7. Perform meiosis, incorporating the error you chose in step 6. 8. Compare the outcome to your hypothesis. Does your data support your hypothesis? If not, revise your hypothesis and repeat steps 6–8. 9. Compare and Contrast How are mitosis and meiosis I similar? How are they different? 10. The Big Idea What is the difference between the chromosomes in cells at the beginning and the end of mitosis? At the beginning and end of meiosis? 11. Critique How did performing cellular replications using pool noodles help you understand mitosis and meiosis? 48 Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Analyze and Conclude Name Date Class Lab B continued Communicate Your Results Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Create a chart of the changes and movements of chromosomes in each of the steps in meiosis and mitosis. Include colored drawings of chromosomes and remember to draw the cell membranes. Extension Investigate some abnormalities that occur when mistakes are made during mitosis or meiosis. Draw a chart of the steps of reproduction showing how the mistake is made. Write a short description of the problems that result from the mistake. Lab Tips • Figure out where the boundaries of your cell are before you start. • Review the phases of mitosis and meiosis before beginning to act out how the chromosomes move during each process. Reproduction of Organisms 49 Name Date Class Lab C Cell Reproduction Directions: Use the information and data from the Lab Mitosis and Meiosis to perform this lab. You have acted out the moves that chromosomes make during mitosis and meiosis. This should help you understand the steps that occur when cells reproduce. Sometimes, during prophase I of meiosis, parts of homologous chromosomes might cross over each other and exchange sections of their chromatids. Crossing over results in new combinations of alleles that increase genetic diversity. Design a procedure similar to the original lab to model how crossing over occurs. You will need to replace the pool noodles with a material that can be cut or broken safely. Please note that you must complete Lab B before beginning Lab C. Have your teacher approve your design and safety procedures before beginning your experiment. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 50 Reproduction of Organisms Name Date Class Chapter Key Concepts Builder Reproduction of Organisms End-of-Chapter Practice Directions: Form small groups. Take turns presenting the following questions to the group. Call on members of your group to discuss the answers. Write the answers that your group has settled on. Then compare your answers with other groups. 1. Why is reproduction important? Include what would happen if living things did not reproduce. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 2. What are the differences between sexual reproduction and asexual reproduction? 3. Why is meiosis important? Directions: Work with a partner. Select one of the options. When you have completed the tasks, present your concept map or diagram to the class. 4. Create a concept map that explains the advantages and disadvantages of sexual reproduction and asexual reproduction. 5. Draw and label what happens to one pair of homologous chromosomes during each stage of meiosis I and meiosis II. Reproduction of Organisms 51 Name Date Class Chapter Test A Reproduction of Organisms Multiple Choice Directions: On the line before each question, write the letter of the correct answer. 1. Which phase occurs first? A. prophase I B. telophase I C. metaphase II 2. Which process is NOT a type of asexual reproduction? A. fission B. mating C. budding 3. Which process is a step in sexual reproduction? A. budding B. fertilization C. regeneration Matching Directions: On the line before each definition, write the letter of the term that matches it correctly. Each term is used only once. 4. cell containing one chromosome from each pair A. diploid 5. produces sex cells B. haploid 6. separate during meiosis I C. meiosis 7. cell containing pairs of chromosomes D. homologous chromosomes Matching Set 2 8. cell division in prokaryotes that forms two genetically identical cells 9. cell division in one-celled eukaryotes E. mitotic F. fission G. budding 10. offspring growing on the body of its parent H. cloning 11. the joining of an egg cell and a sperm cell I. fertilization 12. producing genetically identical organisms in a laboratory 52 Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Matching Set 1 Name Date Class Chapter Test A continued Interpreting a Diagram Directions: Use the diagram to respond to each statement. Mother Father Meiosis a. Meiosis b. c. d. e. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 13. Label this diagram by writing the correct term from the word bank on each line. egg fertilization mitosis sperm zygote 14. Identify which kind of reproduction is shown in the diagram. 15. Tell why meiosis is important. Reproduction of Organisms 53 Name Date Class Chapter Test A continued Short Answer Directions: Respond to each statement on the lines provided. 16. The body cells of a cat have 38 chromosomes. Tell how many chromosomes the body cells of normal kittens will have. Explain how you know. 17. The body cells of a cat have 38 chromosomes. Calculate the number of chromosomes in a cat’s normal sex cells. Explain how you know. 18. Define animal regeneration. Concept Application Directions: Respond to each statement on the lines provided. Use complete sentences. 20. Mammals, including humans, reproduce sexually. Explain the benefits of sexual reproduction. Include the term genetic variation in your response. 54 Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 19. Many organisms reproduce asexually. Explain the benefits of asexual reproduction. Name Date Class Chapter Test B Reproduction of Organisms Multiple Choice Directions: On the line before each question, write the letter of the correct answer. 1. Which phase of meiosis is shown in the diagram to the right? A. anaphase I B. anaphase II C. metaphase I D. metaphase II 2. Which situation is NOT an example of asexual reproduction? A. a pair of rabbits mating B. a bacterium splitting in half C. a paramecium undergoing mitosis D. a new sea star growing from half a sea star Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 3. Which step occurs first in sexual reproduction? A. mating B. meiosis C. cloning D. fertilization Matching Directions: On the line before each definition, write the letter of the term that matches it correctly. Not all terms are used. 4. examples include sperm cells and egg cells A. diploid cell 5. produces egg cells and sperm cells B. haploid cell 6. separate during meiosis I C. meiosis 7. cell containing pairs of chromosomes 8. cell division in prokaryotic organisms that forms two genetically identical cells 9. cell division in unicellular eukaryotic organisms D. homologous chromosomes E. vegetative reproduction F. fission 10. offspring growing on the body of its parent G. budding 11. the joining of an egg cell and a sperm cell H. cloning 12. producing genetically identical organisms in a laboratory Reproduction of Organisms I. mitotic J. fertilization 55 Name Date Class Chapter Test B continued Interpreting a Diagram Directions: Use the diagram to respond to each statement. Mother Father Meiosis a. Meiosis b. c. d. e. 13. Label this diagram by writing the correct term from the word bank on each line. Not egg diploid cell fertilization mitosis sperm zygote haploid cell 14. Compare the number of chromosomes in the zygote, egg, sperm, and parents’ body cells. 15. Explain the role of meiosis in the diagram. 56 Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. all terms are used. Name Date Class Chapter Test B continued Short Answer Directions: Respond to each statement on the lines provided. 16. A sexually reproducing organism has 78 chromosomes in each of its body cells. Predict the number of chromosomes located in the organism’s normal sex cells and in the body cells of the organism’s offspring. 17. Relate the number of chromosomes in a mouse’s sex cells to the number in its body cells. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 18. Compare and contrast vegetative reproduction and animal regeneration. Concept Application Directions: Respond to each statement on the lines provided. Use complete sentences. 19. Outline the advantages and disadvantages of asexual reproduction. 20. Outline the advantages and disadvantages of sexual reproduction. Reproduction of Organisms 57 Name Date Class Chapter Test C Reproduction of Organisms Multiple Choice Directions: On the line before each statement or question, write the letter of the correct answer. 1. In the diagram to the right, which phase of meiosis comes next? A. anaphase I B. anaphase II C. metaphase I D. metaphase II 2. Unlike sexual reproduction, asexual reproduction A. requires sex cells. B. involves a lot of time. C. requires only one parent. D. involves mating two parents. 3. Which result is caused by sexual reproduction? A. one clone B. several sex cells C. new organism(s) D. four haploid cells Directions: On each line, write the term that correctly completes each sentence. 4. The sex cells of a sexually reproducing organism are called cells because of the number of chromosomes they contain. 5. The process of produces egg cells and sperm cells. 6. During meiosis I, the pair of separates. 7. The body cells of a sexually reproducing organism are called cells because of the number of chromosomes they contain. 8. Cell division in prokaryotic organisms is called 9. Many . eukaryotic organisms reproduce asexually by mitotic cell division. 10. The process of an offspring growing on the body of its parent by mitosis and cell division is called . 11. The joining of an egg cell and a sperm cell is called . 12. The process of producing genetically identical individuals from cells in a laboratory is called 58 . Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Completion Name Date Class Chapter Test C continued Interpreting a Diagram Directions: Use the diagram to respond to each statement. Mother Father Meiosis a. Meiosis b. c. d. e. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 13. Label this diagram by writing the correct term on each line. 14. Identify which cells in your diagram are haploid and which ones are diploid. 15. Predict what would happen if meiosis did not occur in your diagram. Short Answer Directions: Respond to each statement on the lines provided. 16. Judge whether sexually reproducing organisms always have an even number of chromosomes in their body cells. Justify your answer. Reproduction of Organisms 59 Name Date Class Chapter Test C continued 17. Predict what would happen if mistakes occurred in the replication or separation of chromosomes during meiosis. 18. Choose two types of asexual reproduction. Compare and contrast them. Concept Application Directions: Respond to each statement on the lines provided. Use complete sentences. 19. Invent a new form of asexual reproduction. Justify how it qualifies as asexual reproduction. Explain the benefits of this form of asexual reproduction. the disadvantages. 60 Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 20. Evaluate whether the advantages of sexual reproduction for mammals outweigh Teacher Pages T2 Answers T6 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Lesson Outlines for Teaching Reproduction of Organisms T1 Lesson Outline for Teaching Lesson 1: Sexual Reproduction and Meiosis A. What is sexual reproduction? 1. Sexual reproduction produces an offspring when genetic materials from two different sex cells combine. a. The female sex cell, a(n) egg, forms in an ovary. b. The male sex cell, a(n) sperm, forms in a testis. 2. During a process called fertilization, an egg cell and a sperm cell join together. The new cell that forms is called a(n) zygote. B. Diploid Cells 1. Organisms that reproduce sexually make two kinds of cells—body cells and sex cells. 2. Body cells are diploid; they have pairs of chromosomes. 3. If a zygote has too many or too few chromosomes, it will not develop properly. 4. Different organisms have different numbers of chromosomes. 5. Homologous chromosomes are pairs of chromosomes that have genes for the same traits arranged in the same order. C. Haploid Cells 1. Sex cells are haploid; they have only one chromosome from each pair of chromosomes. D. The Phases of Meiosis 1. Meiosis involves two divisions of the nucleus and the cytoplasm. These divisions, known as meiosis I and meiosis II, result in four haploid cells. 2. During interphase, the reproductive cell grows and duplicates its chromosomes. 3. During meiosis I, each pair of duplicated homologous chromosomes separates. 4. After meiosis I, the two cells formed during this stage go through a second division of the nucleus and cytoplasm called meiosis II. During meiosis II, sister chromatids separate to produce four haploid cells. E. Why is meiosis important? 1. Meiosis forms sex cells with the correct haploid number of chromosomes. This maintains the correct diploid number of chromosomes in organisms when sex cells join. 2. Meiosis creates genetic variation by producing haploid cells. T2 Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 2. In meiosis, one diploid cell divides and makes four haploid cells. Lesson Outline continued F. How do mitosis and meiosis differ? 1. During mitosis and cell division, a body cell and its nucleus divide once and produce two identical cells. 2. During meiosis, a reproductive cell and its nucleus divide twice and produce four cells––two pairs of identical haploid cells. G. Advantages of Sexual Reproduction 1. Sexual reproduction produces offspring that have a new combination of DNA. This results in genetic variation among individuals. 2. Genetic variation gives individuals within a population slight differences that might be an advantage if the environment changes. 3. Selective breeding has been used to develop desirable traits in plants and animals. H. Disadvantages of Sexual Reproduction 1. One disadvantage of sexual reproduction is that organisms have to grow and develop until they are mature enough to produce sex cells. 2. Another disadvantage is that searching for a mate takes time and energy and might expose individuals to predators, diseases, or harsh environmental conditions. Discussion Question Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. What are some disadvantages of sexual reproduction? Organisms have to grow and develop until they are mature enough to produce sex cells. Searching for a mate takes time and energy and might expose individuals to predators, diseases, or harsh environmental conditions. Reproduction of Organisms T3 Lesson Outline for Teaching Lesson 2: Asexual Reproduction A. What is asexual reproduction? 1. In asexual reproduction, one parent organism produces offspring without meiosis and fertilization. 2. Because the offspring of asexual reproduction inherit all their DNA from one parent, they are genetically identical to each other and their parent. B. Types of Asexual Reproduction 1. Cell division in prokaryotes is known as fission. 2. During fission, DNA is copied and the cell splits to form two identical offspring. The original cell no longer exists. 3. Many unicellular eukaryotes reproduce by mitotic cell division. In this type of asexual reproduction, an organism forms two offspring through mitosis and cell division. 4. In budding, a new organism grows on the body of its parent by mitosis and cell division. When the bud becomes large enough, it can break from the parent and live on its own. 5. Regeneration occurs when an offspring grows from a piece of its parent. a. Sea stars, sea urchins, sea cucumbers, and planarians can reproduce through regeneration. reproduction; new individuals are not produced. 6. Vegetative reproduction is a form of asexual reproduction in which offspring grow from a part of a parent plant. 7. Cloning is a type of asexual reproduction developed by scientists and performed in laboratories. It produces identical individuals from a cell or from a cluster of cells taken from a multicellular organism. 8. Using a cloning method called tissue culture, plant growers and scientists use a meristem to make a copy of a plant with desirable traits. 9. Because all of a clone’s chromosomes come from one parent, the clone is a genetic copy of its parent. 10. Asexual reproduction enables organisms to reproduce without a(n) mate. 11. Asexual reproduction also enables some organisms to rapidly produce a large number of offspring. 12. Asexual reproduction produces offspring that are genetically identical to each other and to their parent. This results in little genetic variation within a population. T4 Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. b. Many animals can regenerate damaged or lost body parts. This is not Lesson Outline continued 13. Genetic variation is important because it can increase an organism’s chance of surviving if the environment changes. 14. Genetic changes, called mutations, can occur and then be passed to offspring; this can affect the offspring’s ability to survive. Discussion Question How can a plant be cloned without laboratory equipment? Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Take a piece of the plant and plant it in soil so the piece grows as a new plant. Reproduction of Organisms T5 Answers What do you think? (page 1) 1. Agree; body cells divide mitosis. Sex cells are produced by meiosis. 2. Disagree; variation is caused by genetic factors; parent organisms contribute different traits to the offspring. 3. Disagree; healthy offspring can be produced by one parent organism through asexual reproduction. 2. Two haploid cells are needed to make a zygote, because each haploid cell (egg and sperm) has only one half of the pair of chromosomes needed to create a diploid cell (the zygote). 3. One cell divides into two cells. Then each of those two cells divide again, forming a total of four cells. Content Practice A (page 13) 4. Agree; all the individuals produced through cloning have the same DNA. 1. G 5. Disagree; only one parent is required for asexual reproduction. 3. H 6. Disagree; asexual reproduction occurs in unicellular and multicellular organisms. 5. I 2. B 4. C 6. A Lesson 1 7. D Launch Lab (page 8) 8. F 1. Answers will vary, but students should see differences in the model offspring. 2. The model offspring looked different because they inherited different traits from their parents. 3. The offspring would get genetic information from both parents, which would create variations. Variations within a species might allow organisms to adapt to environmental changes. Content Vocabulary (page 9) 2. Fertilization is the joining of the egg and sperm that produces a zygote, which will develop into a new organism. 3. Haploid cells, like sex cells, have only one set of chromosomes. Diploid cells, like most body cells, have pairs of chromosomes. 4. Sexual reproduction involves putting together the DNA of two different sex cells through fertilization. 5. A diploid cell has homologous chromosomes, or pairs of chromosomes—one from each parent. 6. Meiosis separates pairs of homologous chromosomes, which are made of DNA, resulting in haploid cells. 7. Meiosis begins with one diploid cell and produces four haploid cells. MiniLab (page 12) 1. During meiosis I, the double-stranded chromosomes separated into two cells. During meiosis II, the two strands of double-stranded chromosomes separated into the four haploid cells. T6 10. F 11. T 12. F Content Practice B (page 14) 1. Sexual reproduction is the production of an offspring that results when the genetic material from two different cells combine. 2. Male sex cells are sperm, and they form in the testes. Female sex cells are eggs, and they form in the ovaries. 3. A zygote is a new cell that forms when an egg cell and a sperm cell join during fertilization. 4. A diploid cell has pairs of chromosomes and is located in body cells. A haploid cell has only one chromosome from each pair and is located in sex cells. 5. meiosis; two 6. Homologous chromosomes are pairs of chromosomes that have genes for the same traits arranged in the same order. Language Arts Support (page 16) 1. Meiosis is a type of cell division. 2. Mitosis is a different process by which cells divide. Sexual reproduction only occurs among some organisms. Possible answer: The writer should delete both sentences. The paragraph is about meiosis, not mitosis. The last sentence could be a main idea for a different paragraph. 3. Possible response: Meiosis occurs in certain cells in an organism’s reproductive system. 4. Possible response: This process occurs in certain cells in an organism’s reproductive system. Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 1. The egg is the female sex cell, and the sperm is the male sex cell. 9. E Answers continued Applying the Skill Revised drafts will vary but should reflect the use of the four levels of revisions presented in the lesson. Writing should reflect a clear idea. Math Skills (page 17) 11. meiosis Key Concept Builder (page 21) 1. 14 1. interphase 2. 188 2. Homologous chromosomes 3. 18 mm 3. breaks 4. 24 mm 4. middle School to Home (page 18) 5. Spindle 1. An egg cell and a sperm cell combine during fertilization. This creates a new cell called a zygote. 6. homologous 2. Sex cells are haploid cells. 9. Sister chromatids 3. Meiosis occurs only during the formation of certain sex cells in eukaryotic organisms, whereas mitosis occurs in nearly all eukaryotic cells. Meiosis involves two divisions of the nucleus and the cytoplasm and produces four haploid daughter cells. Mitosis involves only one division of the nucleus and the cytoplasm and produces two diploid daughter cells. 4. Advantages of sexual reproduction: It results in genetic variation that can protect organisms from changes in their environment, and it allows for selective breeding. Disadvantages of sexual reproduction: It takes time and energy, exposes individuals to dangers, and is limited by factors such as pregnancy. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 9. sister chromatids 10. meiosis; meiosis Key Concept Builder (page 19) 1. sexual reproduction 2. female sex cells 3. male sex cells 4. Fertilization is the joining together of an egg cell and a sperm cell. The new cell that forms is called a zygote. 5. It develops into a new organism. 6. Half of an offspring’s DNA comes from each parent. 7. Offspring are not likely to inherit the same DNA from the same parents. Key Concept Builder (page 20) 1. diploid; haploid 2. haploid; diploid 3. diploid 4. homologous chromosomes 5. homologous chromosomes 6. sister chromatids 7. meiosis 8. sister chromatids Reproduction of Organisms 7. Sister chromatids 8. two 10. Chromosomes; Nuclear membrane 11. align 12. pulled apart; opposite ends of the cells 13. chromosomes 14. four 15. half Key Concept Builder (page 22) 1. 40 2. 20 3. 20 4. 40 5. 20 6. Possible answer: A diploid cell is a cell that has the correct number of chromosomes for a species. It is a body cell. A haploid cell has half the number of chromosomes as a diploid cell. It is a sex cell. 7. Possible answer: Meiosis produces haploid sex cells. These cells have half the number of chromosomes as a diploid cell in an adult organism of a species. When the sex cells combine, the fertilized egg has a haploid set of chromosomes from each parent. It is a diploid cell that develops into a diploid offspring. Enrichment (page 23) 1. For many generations, native plants that were resistant to disease and pests survived and reproduced. The resistant traits were passed on to their offspring. Meanwhile, those native plants that were not resistant to disease and pests died off. Eventually, the population of native plants was made up mainly of resistant plants. 2. Possible answers: Preserve all: Many plants that have no current known value might have important uses in the future. Saving plants that aren’t useful to people is still necessary because other organisms might T7 Answers continued depend upon these plants for survival. Preserve some: Because of budget restrictions, some plants might be targeted for preservation and others are allowed to become extinct. In this situation, it would be best to determine which plants are likely to be useful to people. Challenge (page 24) Prophase I: Chromosomes appear as homologous pairs. Metaphase I: Chromosomes align in the middle of the cell. Anaphase I: Each pair of homologous chromosomes is pulled apart. Telophase I: Chromosomes are pulled to the opposite ends of the cell, and the cytoplasm divides. Prophase II: Nuclear membrane breaks apart. Metaphase II: Pairs of sister chromatids align in middle of the cell. Anaphase II: Sister chromatids begin to separate and move to opposite ends of the cells. Telophase II: A nuclear membrane forms around each set of chromatids, and the cytoplasm divides. Lesson 2 Launch Lab (page 28) 1. Small cells are attached to larger cells. 2. Only one parent produced offspring during this process. Content Vocabulary (page 29) 1. fission 2. budding 3. culture 4. potential 5. regeneration 6. asexual reproduction 7. vegetative reproduction 8. cloning MiniLab (page 32) Lesson Quiz A (page 25) 1. A single parent plant produces a new plant. Matching Set 1 1. C 2. Possible answer: Farmers could use this method to produce multiple plants with desired characteristics. 2. B 3. A Matching Set 2 4. F 3. Answers will vary, but students should describe one type of vegetative reproduction. Content Practice A (page 33) 5. D 1. asexual reproduction 6. E 2. genetically identical 8. A 3. fission 4. mitotic cell division 5. budding Lesson Quiz B (page 26) 6. regeneration Completion 1. meiosis 7. vegetative reproduction 2. Fertilization 3. sexual reproduction 4. zygote 5. nucleus 6. homologous chromosomes Short Answer 7. Answers will vary but should mention that during meiosis I, each pair of homologous chromosomes separates; each homologous chromosome from the pair is pulled toward an opposite end of the cell. During meiosis II, sister chromatids separate and four haploid daughter cells form. 8. Answers will vary but should include that because meiosis produces haploid sex cells, it helps maintain the correct number of chromosomes in each generation of offspring, and it allows for genetic variation. T8 8. cloning 9. tissue culture 10. nucleus Content Practice B (page 34) 1. T 2. T 3. F; multicellular 4. F; asexual reproduction 5. T 6. T 7. F; An advantage 8. F; fission 9. F; nucleus 10. T Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Multiple Choice 7. B Answers continued School to Home (page 35) 1. Possible answer: How do sponges use budding to reproduce? 2. Possible answer: A sponge grows offspring, called buds, on its body. The buds can break off and grow into sponges, or they can continue to live on the parent. 3. Possible answer: I will get slides of budding sponges and look at them under a microscope. I will also get a live budding sponge and see how the buds grow on the sponge. I will break off a bud and see whether it is able to grow on its own. 4. Possible answer: I will describe and draw what I see under the microscope. I will make a sketch of the live sponge and sketches of the bud over a period of two weeks, to show whether the bud is growing. 5. Possible answer: Live budding sponges or slides of budding sponges might not be available. I could use another organism that buds, such as a hydra. Key Concept Builder (page 36) 1. Asexual reproduction is the production of offspring by one parent, which results in offspring that are genetically identical to each other and the parent. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 2. They are genetically identical to their parent because they inherit all their DNA from one parent. 3. fission, mitotic cell division, budding, regeneration, vegetative reproduction, cloning 4. By cloning a plant with desirable traits, copies of the plant are made. Each copy has the same desirable trait, such as sweet fruit or plants that are disease-resistant. 5. They don’t have to find a mate, and some organisms can produce a large number of offspring in a short amount of time. Key Concept Builder (page 37) 1. Possible answers: (in any order) cell division in prokaryotes, simpler that mitosis, DNA molecule but no nucleus 2. Possible answers: (in any order) asexual reproduction, unicellular organisms, organism divides into two offspring 3. Possible answers: (in any order) occurs in unicellular eukaryotes, involves mitosis and cell division, nucleus and cytoplasm divide 6. Students’ drawings should include a planarian cut in half and two offspring that have grown their missing half. 7. Offspring grow from a piece of its parent. 8. Students’ drawings should include a new plant growing from an adult plant, such as a strawberry plant growing from a stolon produced by the parent plant or another plant growing from a stem, root, or leaf of a parent plant. 9. Offspring grow from a part of a parent plant, such as a root, stem, or leaf of the plant. Key Concept Builder (page 38) 1. no check mark 2. check mark 3. check mark 4. no check mark 5. check mark 6. no check mark 7. Possible answer: Cloning is a form of asexual reproduction that produces genetically identical offspring. It is a technique developed by scientists and does not occur in nature. Offspring are produced from a cell or a cluster of cells taken from a multicellular organism. Key Concept Builder (page 39) 1. In the past, cloning described any process that produced genetically identical offspring. Today, cloning usually refers to a type of asexual reproduction developed by scientists and performed in laboratories. 2. Vegetative reproduction is most similar to animal regeneration because in both types of asexual reproduction a new organism grows from a part of the parent organism. 3. No; a new organism was not produced. 4. Possible answer: A tissue culture is done by humans. It does not occur in nature. Vegetative reproduction occurs in nature. Enrichment (page 40) 1. The extreme cold that preserved the woolly mammoths also damaged their cells. Scientists need whole cells to clone an animal. 2. Possible answer: Scientists might be able to understand why the animal became extinct. They might also learn more about the animal’s physical characteristics and its behaviors, as well as its environment. 4. Students’ drawings should include a small hydra growing from the side of an adult hydra. Challenge (page 41) 5. A new organism grows on the body of its parent by mitosis and cell division. When it is big enough, it can break off and live on its own. Possible hypothesis: A new plant will grow from a part of a parent plant if the part is placed in water. Possible procedure: Use scissors to cut a leaf from a Reproduction of Organisms T9 Answers continued plant. Place the cutting in a jar of water. Place the jar of water in a warm, sunny location. Observe the cutting for ten days. Record your observations in a data table. Lesson Quiz A (page 42) Multiple Choice 1. B 2. C Matching Set 1 3. B 4. A 5. C Matching Set 2 6. D 7. F 8. E Lesson Quiz B (page 43) Completion 1. fission 2. Budding 3. regeneration 4. asexual reproduction 5. cloning 6. plant 8. Answers will vary but could include that organisms can reproduce without a mate and that organisms can rapidly produce a large number of offspring. Labs A and B (pages 44, 47) 9. In both mitosis and meiosis I, replicated chromosomes are separated into daughter cells. A difference is that homologous chromosomes line up next to each other in metaphase I of meiosis, but they do not line up next to each other in metaphase of mitosis. Another difference is that at the end of meiosis I, daughter cells contain replicated sister chromatids, but after mitosis, cells contain a single copy of the chromosome. 10. Cells are identical at the beginning and at the end of mitosis. At the beginning of meiosis, cells contain pairs of homologous chromosomes. At the end of meiosis, cells contain only one chromosome from the pair of homologous chromosomes. T10 Communicate Your Results Students’ charts should depict the following stages of mitosis and meiosis. Charts should include written descriptions of common organelles and the function they perform at each stage of mitosis and meiosis. Nuclear membrane, chromosomes, and cell membrane should be clearly labeled in each drawing. Example: Mitosis: stage 1, Interphase, G2, chromosomes replicate; stage 2, prophase, nuclear membrane breaks down; stage 3, metaphase, chromosomes line up in middle of cell; stage 4, anaphase, sister chromatids move to opposite sides of cell; stage 5, telophase, nuclear membrane forms around chromosomes Meiosis: stage 1, interphase, G2, chromosomes replicate; stage 2, prophase I, nuclear membrane breaks down; stage 3, metaphase I, homologous chromosomes line up next to each other in middle of cell; stage 4, anaphase I, one of each pair of homologous chromosomes move to opposite sides of cell; stage 5, telophase, nuclear membrane forms around chromosomes; stage 6, prophase II, nuclear membrane breaks; stage 7, metaphase II, chromosomes line up in the center of the cell; stage 8, anaphase II, sister chromatids move to opposite sides of the cell; stage 9, nuclear membrane forms around chromosomes B. Extension Numerous genetic disorders are caused by errors in meiotic division. Many are related to the nondisjunction of sex chromosomes. For example, Turner syndrome occurs when a female has an XO genotype. Turner syndrome results in women who are sterile, generally short in stature, and have folds of skin around their necks. Women with Trisomy X have a genotype XXX. Many women with this defect have very little abnormality. Kleinfelter syndrome results from a genotype XXY. Many of these men show mixed secondary sexual characteristics. Men with a genotype XYY tend to be taller than average. In terms of autosomal chromosomes, the most common nondisjunctions result in chromosomes 13, 18, and 21. Most often an embryo with only one copy of an autosomal chromosome does not survive. Trisomy 21 is also called Down syndrome. Trisomy 18 is called Edwards syndrome, and it results in severe abnormalities. Trisomy 13 is called Patau syndrome. Lab C (page 50) Sample procedure: Ask a Question How does crossing over occur during prophase I of meiosis? Form a Hypothesis Students’ hypotheses will vary, but the following is an example: If parts of chromosomes cross over each other, then genetic diversity will increase because new combinations of alleles will be formed. Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Short Answer 7. Answers will vary but should include fission (prokaryotes such as bacteria), budding (hydra, yeasts), animal regeneration (sponges, planarians, sea stars), or vegetative reproduction (strawberries, raspberries, potatoes, geraniums). 11. Answers will vary. Accept any reasonable response. Answers continued Test Your Hypothesis Testing procedures will vary, but the following is an example: Perform mitosis. a. During prophase, the nuclear membrane breaks apart, and the nucleolus disappears. 5. C b. In metaphase, duplicated chromosomes align in the middle of the cell. 7. A c. Each pair of chromosomes is separated in anaphase. d. In telophase, the nuclear membrane re-forms. Two daughter cells are formed. 6. D Matching Set 2 8. F 9. E 10. G Repeat all steps. 11. I Perform meiosis. 12. H a. In prophase I, the nuclear membrane breaks apart, the nucleolus disappears, and homologous chromosomes pair up. Two homologous chromosomes cross over and exchange sections. b. In metaphase I, homologous chromosomes line up along the center of the cell. c. During anaphase I, the pairs of homologous chromosomes separate. d. In telophase I, the nuclear membrane reforms. e. Each daughter cell now performs meiosis II independently. In prophase II, the nuclear membrane breaks down, and the nucleolus disappears. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 3. B Matching Set 1 4. B f. During metaphase II, duplicated chromosomes align in the middle of the cell. g. Each pair of chromosomes is separated in anaphase II. h. In telophase II, the nuclear membrane re-forms. Analyze and Conclude Students should present an analysis of their data and some conclusion. Chapter Key Concepts Builder (page 51) 1. Reproduction ensures the survival of species. If living things stopped reproducing, they would eventually die off. 2. Sexual reproduction is the production of offspring by the joining of a sperm and an egg. Asexual reproduction is the production of offspring by one parent. 3. Meiosis is important because it maintains the chromosome number of a species from one generation to the next. 4–5. Answers will vary. Diagrams or concept maps should make clear, accurate connections. Chapter Test A (page 52) Multiple Choice 1. B 2. A Reproduction of Organisms Chapter Test A (page 53) Interpreting a Diagram 13. a. egg; b. sperm; c. fertilization; d. zygote; e. mitosis 14. sexual reproduction 15. Answers will vary but should include that meiosis is important because it provides genetic variation and maintains the correct number of chromosomes in cells. Chapter Test A (page 54) Short Answer 16. Each body cell in the kittens will have 38 chromosomes. The body cells of offspring have the same number of chromosomes as the parents’ body cells. 17. There will be 19 chromosomes in a normal cat’s sex cells. Sex cells have half the number of chromosomes as body cells. 18. Animal regeneration is a type of asexual reproduction that occurs when an offspring grows from a part of its parent. Concept Application 19. Answers will vary but should include that asexual reproduction allows organisms to produce a large number of offspring in a short amount of time. It also allows an organism to reproduce without a mate. 20. Answers will vary but should include that sexual reproduction produces offspring that have half their genetic material from each of two parents, which produces genetic variation among the offspring. Thus, each offspring has a slightly different set of traits, which might make it resistant to disease or help it survive if the environment changes. Chapter Test B (page 55) Multiple Choice 1. C 2. A 3. B T11 Answers continued Matching 4. B 5. C 6. D 7. A among the offspring. Disadvantages are that sexual reproduction takes a lot of time and energy to carry out. Moreover, offspring have to mature to an age when they can produce sex cells, find a mate (which has risks), and reproduce (in some cases only at certain times). 8. F Chapter Test C (page 58) 9. I Multiple Choice 1. A 10. G 11. J 12. H Chapter Test B (page 56) Interpreting a Diagram 13. a. egg; b. sperm; c. fertilization; d. zygote; e. mitosis 14. The egg and sperm are haploid cells and have half the number of chromosomes as the diploid zygote and the diploid parents’ body cells. 15. Meiosis produces the sex cells (egg and sperm) and ensures that these cells have the haploid number of chromosomes. Chapter Test B (page 57) Short Answer 16. The organism’s sex cells each have 39 chromosomes, and the body cells of the organism’s offspring each have 78 chromosomes. 18. Answers will vary but should include that vegetative reproduction and animal regeneration are forms of asexual reproduction that involve an offspring growing from a part of its parent. Animal regeneration occurs in some animals, whereas vegetative reproduction occurs in some plants. Concept Application 19. Answers will vary. Advantages are that asexual reproduction allows organisms to produce a large number of offspring in a short amount of time. It also allows an organism to reproduce without a mate. Disadvantages include that the offspring are genetically identical to their parents, which means that they are vulnerable to the same disease and problems as their parents. Also, mutations can occur and then be passed to offspring, which can have a negative impact on the offspring’s ability to survive. 20. Answers will vary. Advantages include that sexual reproduction produces offspring that have half their genetic material from each of two parents, which produces genetic variation T12 3. C Completion 4. haploid 5. meiosis 6. homologous chromosomes 7. diploid 8. fission 9. unicellular 10. budding 11. fertilization 12. cloning Chapter Test C (page 59) Interpreting a Diagram 13. a. egg; b. sperm; c. fertilization; d. zygote; e. mitosis 14. The sperm and egg are haploid. The zygote and parents’ body cells are diploid. 15. The sex cells would not have the correct number of chromosomes—they would be diploid rather than haploid. When the egg and sperm combined, the zygote would have twice as many chromosomes as a normal cat. Short Answer 16. Answers will vary. Students might agree that sexually reproducing organisms always have an even number of chromosomes in their body cells because the cells have pairs of chromosomes (homologous chromosomes). If students disagree, they must justify their answer, perhaps by saying that there are always exceptions to the rule. Chapter Test C (page 60) 17. Answers will vary but should include that mistakes in chromosome replication or separation would result in the sex cells containing a different number of chromosomes than half the diploid number. In this case, the resulting zygote might not be completely normal or viable. 18. Answers will vary. Students should choose two of the following and compare them: budding, fission, mitotic cell division, animal regeneration, vegetative reproduction, cloning. Reproduction of Organisms Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 17. The mouse’s body cells contain pairs of chromosomes, whereas its sex cells contain one chromosome of each pair. Thus, the sex cells have half the number of chromosomes in the body cells. 2. C Answers continued Concept Application 19. Answers will vary but should describe a form of asexual reproduction that involves one parent and produces genetically identical offspring. Advantages include that asexual reproduction allows organisms to produce a large number of offspring in a short amount of time and without having to find a mate. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 20. Answers will vary but should link the advantages and disadvantages of sexual reproduction to the life of a mammal. Advantages include that sexual reproduction produces genetic variation among offspring, which can be beneficial to the survival of some offspring. Disadvantages are that sexual reproduction takes a lot of time and energy to carry out. In addition, offspring have to mature to an age when they can produce sex cells, find a mate, and so forth. Reproduction of Organisms T13