Mitosis
Transcription
Mitosis
Teacher’s Guide Mitosis Grades 5-9 MTTV CREDITS Program Production S u n b u r s t Vi s u a l M e d i a Te a c h e r ’s G u i d e Te r r y G a t e s Print Material Design Cecile Foshee © 2004 Sunburst Visual Media, a division of Global Video, LLC Hawthorne, NY 10532 Approximate running time: 32 minutes Mitosis Video Quiz Table of Contents Guide Information ....................................05 Fast Facts..................................................07 Before Viewing Activities ..........................10 During Viewing Activities ..........................14 After Viewing Activities ............................16 After Viewing Quizzes ..............................20 Additional Resources ................................25 Answer Keys ............................................27 Script........................................................37 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz About This Guide Guide Information Providing students with visual media is an excellent way to take them out of the classroom and into the real world. Our programs offer real-world footage, dynamic graphics, engaging dramatizations, and first-person testimonials that keep students interested and help them visualize difficult concepts. More importantly, they reinforce critical learning objectives shaped by state and national educational standards. However, the learning doesn’t begin and end when the program does. You can make the learning experience even more effective by using the materials provided in this Teacher’s Guide. This guide is divided into the following sections: • Fast Facts are designed to give your students a quick overview of the information presented within the video. • Before Viewing Activities help identify what students already know about the subject, what they are curious about, and what they hope to learn. • During Viewing Activities may be used during viewing to enhance students’ understanding of the video. • After Viewing Activities help students summarize and draw conclusions from the information that was presented. • After Viewing Quizzes test students’ retention of the information presented in the program and activity sheets. • Additional Resources are designed to help you extend the information presented in the program into other areas of your curriculum. • Answer Keys are provided for relevant activities or reproducible pages. • Script content is provided in an unabridged version for future reference. 5 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz Program Overview Guide Information Join Professor Science as he presents the basic concepts about mitosis. He explains what mitosis is, names and describes the main parts of the cell that are involved in mitosis as well as exploring the steps of its process. The program is divided into two sections and at the conclusion of each one, interesting characters assess your students’ understanding of the concepts through multiple-choice and true/false questions. Answers are provided at the conclusion so students can self check their work. Viewing Objectives Upon watching the Mitosis Video Quiz DVD/Video, participating in the discussions, and completing the activities given in the program guide, students will be able to: • Define mitosis • List the stages of the mitosis process • Describe what occurs in each stage of the process • Explain why mitosis is important in the creation of new cells • Define key vocabulary related to mitosis • Respond to multiple choice and true/false questions 6 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC Mitosis Fast Facts Fast Facts 1. Every living thing is made of cells. • All living things go through mitosis in order to grow. 2. When organisms grow up, the cells don’t get larger, they multiply in number. • Living things need to create new cells as bones, muscles, and skin grows. • Cells don’t last forever so our bodies are always replacing old or damaged cells with new ones. • Tissue cells are called somatic; they are the basic unit that makes up our body tissues and organs such as hair, skin, or lung cells. • These somatic cells are for growth; they are not for reproduction. 3. Mitosis is the division of somatic cells to create new, identical cells. • During mitosis, each cell divides to make two new cells. • These two cells divide to make four new cells, and these four make eight new cells, etc. 4. Each • • • • cell has parts: The nucleus controls the cell functions. Organelles outside the nucleus perform specialized tasks. Cytoplasm holds the organelles in place. The cell membrane separates the cell from other cells and lets nutrients in and waste out. 5. Different cell types have different cycles. • Not all cells reproduce and replace themselves, such as nerve cells. • Some cells have a faster division rate than others. 6. A cell’s cycle begins with the longest stage called interphase. • During this stage, the organelles produce energy and proteins to grow and build new cells. • Organelles duplicate themselves during interphase. • Genetic material in the nucleus is duplicated. • The cell is now ready for mitosis. 7. Somatic cells are eukaryotic, that is, they have a distinct nucleus. • The nucleus is like the brain or control center of the cell. • The nucleus contains DNA, which is our genetic code. • DNA molecules join together to make up a complex strand called a chromosome. • Genetic codes are different for every person in the world. 7 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz Mitosis Fast Facts Fast Facts 8. Somatic cells have a certain number of chromosomes inside their nuclei, depending on what organism it is. • Examples are: pea plants have 14, gorillas have 48, and goldfish have 94 chromosomes in each cell. 9. Somatic human cells have 23 pairs of chromosomes or a total of 46. • Humans have 23 pairs or 46 chromosomes in each cell. • This is a diploid cell, which means it has the full number of chromosomes. • Other cells are haploid cells, which means they have one-half of the chromosomes. • Haploid cells are the result of cell division for reproduction only. 10. Chromosomes start out as a tangled ball of long thin strands called chromatin. • During interphase the chromosomes extend and replicate. • The duplicated chromosomes join together at a central point called a centromere. • At this stage, the joined chromosomes are called chromatids. 11. The original cell is called the parent cell and new cells are called daughter cells. • The pairs of chromosomes from the original cell are called sister chromosomes and the duplicate ones are called daughter chromosomes. 12. There are four stages to mitosis: prophase, metaphase, anaphase, and telophase. 13. Prophase • The chromosomes condense. • Nuclear membrane and nucleolus disappear. • Spindle fibers form and centrioles migrate apart. • Chromatids attach to spindle fibers. 14. Metaphase • Chromatids align at center or equator of the cell. • Chromatids are pulled by the spindle fibers. 15. Anaphase • Centromere of each chromatid splits. • One chromatid from each chromosome moves to centrioles at poles of cell. 8 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC Mitosis Fast Facts Fast Facts 16. Telophase • Spindle fibers break down. • Chromosomes elongate and become tangled in a ball of chromatin again. • Nucleolus reappears. • Nuclear envelope forms around separate set of chromosomes. 17. The rest of the cell divides. • Cytokinesis occurs, that is, the cytoplasm divides as the cell membrane pinches inward and cuts the cell in half. • Now there are two new daughter cells, separated and independent of each other and each with its own nucleus and organelles. • The formation of these two new daughter cells now has the correct number of chromosomes. 18. Mitosis starts over again. 19. Cells separate differently in plants and animals. • Wall of plant cells is more rigid than animal cell membrane. • A cell plate develops until two cells are separated. 9 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz Before Viewing Activity 1 Name What We Know Prior to watching Mitosis Video Quiz video/DVD, provide students with an opportunity to share what they know about mitosis using this KWL chart. PURPOSE OF MITOSIS ANIMAL VS PLANT CELLS K W L MITOSIS PROCESS INTERPHASE 10 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC Before Viewing Activity 2 Name Before Viewing Discussion Teacher Note: Prior to asking your students to complete “Think-Pair-Share” on page 13, ask the following questions to help them focus on the topic. Space has been provided below for notes, additional questions, or their reflections of this activity. 1. Why is mitosis important to all living things? 2. How do animal and plant cells behave differently during mitosis? 3. What are the four stages of mitosis? 4. How do traits of a mother and father get passed on to their offspring? 5. What connection does the cell cycle called interphase have to do with mitosis? NOTES: 11 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz Before Viewing Activity 3 Name Vocabulary Teacher Note: Prior to watching the program, be sure to provide your students an opportunity to become familiar with the following vocabulary words and their meanings. 1. DNA – deoxyribonucleic acid; the unique genetic code for every living thing 2. INTERPHASE – a stage of mitosis during which exact copies of chromosomes are made 3. CENTROMERE – a single point where two chromatids are held together 4. CHROMOSOMES – strands of genetic codes made up of DNA molecules 5. SOMATIC – any cell that is not a reproductive cell 6. HAPLOID – in humans, a type of cell that contains a total of 23 chromosomes, half of what a diploid cell has 7. CHROMATIDS – two identical chromosomes that split and contain the same genetic material 8. MITOSIS – division of somatic cells to create new cells 9. DIPLOID – a type of cell that contains 23 pairs or a total of 46 chromosomes 10. EUKARYOTIC – cells that have a clear, distinct nucleus 11. CENTRIOLES – two small parts in animal cells that direct the movement of chromosomes during mitosis 12. POLES – opposite ends of a cell 13. CYTOKINESIS – when a cell’s cytoplasm divides and cuts the cell in half and the result is two cells in place of one 14. ANAPHASE – third stage of mitosis; spindle fibers pull chromatids to opposite poles 15. DUPLICATE – to make an exact copy of 16. NUCLEAR MEMBRANE – envelope around nucleus of a cell 17. PROPHASE – first stage of mitosis; chromosomes become visible and centrioles move towards poles 18. ALIGN – to line up 19. METAPHASE – second stage of mitosis; nuclear membrane dissolves and chromatids align in center of cell 20. TELOPHASE – fourth stage of mitosis; chromosomes at opposite poles, spindle fibers break down, and a nuclear envelope forms around both sets of chromosomes 12 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC Before Viewing Activity 4 Name Think-Pair-Share Teacher Note: Two heads are better than one and this activity will jump-start your students’ journey into the world of mitosis! The following process will help your class generate questions they have about cell division. SUPPLIES: • index cards • pens/pencils • large sheet of paper/ overhead/white board Step 1: THINK – Provide several minutes of quiet time for students to think about the process of mitosis and the questions they may have. Step 2: PAIR – Assign each student a partner. Hand each pair 5 note cards. Direct the partners to discuss questions they have and to write down five of the most interesting ones. Step 3: SHARE – Ask each group to stack their cards with their “best” question on top. Go around the room and ask each group to share their top question. Write the question where all can see. After collecting the best question from each group, continue with more questions. Review them prior to watching Mitosis Video Quiz video/DVD. Use these as the focus for watching the program. 13 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz During Viewing Activity 1 Name Sequencing Wheel Graphic Organizer Complete the graphic organizer as you watch Mitosis Video Quiz video/DVD. The Mitosis Process 14 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC During Viewing Activity 2 Name Stages Web What is mitosis? What are the stages? What happens during each stage? Complete this graphic organizer while viewing the Mitosis Video Quiz video/DVD. Definition of mitosis: The stages: Purpose of mitosis: What occurs: 15 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz After Viewing Activity 1 Name The “What” Web Organizer After watching the Mitosis Video Quiz video/DVD, fill in the information missing from the following “what” questions below. • What is mitosis? • What is the purpose of this process? • What happens before cell division can take place? • What are the stages of mitosis? • What do chromosomes have to do with mitosis? • What is the reason this process is so important to all life? 16 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC After Viewing Activity 2 Name Extra! Extra! Read All About It! Go back in time to the moment scientists discovered the process of mitosis! Imagine what the front page of a major newspaper would look like. Create a headline, lead article, and illustration that shares key information. Use at least five vocabulary words in your article. _____________________________________________________________________ _____________________________________________________________________ Headline ____________________________________ ____________________________________ ____________________________________ ____________________________________ ____________________________________ ____________________________________ ____________________________________ ____________________________________ ____________________________________ ____________________________________ ____________________________________ ____________________________________ ____________________________________ ____________________________________ ____________________________________ ____________________________________ ____________________________________ Illustration ____________________________________ 17 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz After Viewing Activity 3 Name Stages of Mitosis Name each stage of mitosis and write a brief description in the box of what takes place during that stage. Make a sketch of each stage in each of the circles. Stage: Description: Stage: Description: The Stages of Mitosis Stage: Description: Stage: Description: 18 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC After Viewing Activity 4 Name Cell Division Match the different steps of cell division with the correct label. cell division parent cell cell growth daughter cells Draw the steps in the proper order. Label each. The last step has been completed for you. Then, write a summary statement about this process. ______________ ______________ ______________ daughter cells Summary: _______________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ 19 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz After Viewing Quiz 1 Name Mitosis Quiz Mark the correct answer. 1. Mitosis: a. Takes place only in brain tissue b. Is how cells reproduce and tissues grow c. Divides only the cell nucleus d. Creates cells that are different from each other 2. Human haploid cells have: a. 23 pairs of chromosomes b. 46 chromosomes c. 23 chromosomes d. A and B 3. TRUE OR FALSE: Mitosis is the division of somatic cells to create new, identical cells. 4. Humans have _____chromosomes in their somatic cells. a. 47 b. 46 c. 23 d. 48 5. A eukaryotic cell has: a. No nucleus b. A distinct nucleus c. An indistinct nucleus d. Two nuclei 6. Chromosomes are made of: a. Sugar and spice b. DNA molecules c. DNA and cytoplasm d. The liquid from the cell 7. Chromatids are joined together at a point called the ___________. a. Center point b. Middle c. Nucleus d. Centromere 20 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC After Viewing Quiz 1 Name Mitosis Quiz (cont.) 8. Diploid cells have: a. 23 pairs of chromosomes b. 46 chromosomes c. 23 chromosomes d. A and B 9. The genetic information for an organism is found: a. In the cell nucleus b. In the cytoplasm c. In the cell membrane d. All of the above 10. The cytoplasm: a. b. c. d. Is a thick liquid Is another name for the nucleus Holds many of the cell’s organelles A and C 11. During prophase, the centrioles: a. b. c. d. Join together Move to center of cell and form 2 separate poles Move to opposite ends of cell and form 2 separate poles None of the above 12. The four stages of mitosis in their correct order are: a. b. c. d. Prophase, metaphase, anaphase, telophase Prophase, telophase, anaphase, metaphase Anaphase, prophase, metaphase, telophase Telophase, metaphase, anaphase, prophase 13. TRUE OR FALSE: In plants and animals, the cell membrane pinches the divided cell mass into two cells. 14. The chromosomes are pulled apart by the spindle fibers during which stage: a. b. c. d. Anaphase Interphase Telophase Prophase 21 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz After Viewing Quiz 1 Name Mitosis Quiz (cont.) 15. During interphase: a. b. c. d. The cell grows Chromosomes start to duplicate The cell prepares for mitosis All of the above 16. During metaphase: a. b. c. d. The chromosomes duplicate The spindle fibers attach to the centromere The cell membrane closes around the new cells The chromatids split at the centromere 17. TRUE OR FALSE: During metaphase, the nuclear membrane finishes breaking down. 18. In which stage do the nuclear envelopes form around the separate sets of chromosomes: a. Anaphase b. Interphase c. Telophase d. Prophase 19. After mitotic cell division, or mitosis, the daughter cells contain: a. b. c. d. Half of the chromosomes of the parent cell The same number of chromosomes as the parent cell A random number of chromosomes An unknown number of chromosomes 20. What structure inside the cell helps pull the chromatids apart: a. b. c. d. Centromere Spindle Fibers Nucleus Membrane 22 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC After Viewing Quiz 2 Name Vocabulary Quiz A Choose the vocabulary word to make each statement correct. 1. A. DNA B. INTERPHASE C. D. E. F. CENTROMERE CHROMOSOMES SOMATIC HAPLOID G. CHROMATIDS H. I. MITOSIS DIPLOID J. EUKARYOTIC deoxyribonucleic acid; the unique genetic code for every living thing a stage of mitosis during which exact copies of chromosomes are made a single point where two chromatids are held together strands of genetic codes made up of DNA molecules any cell that is not a reproductive cell a type of cell that contains a total of 23 chromosomes, half of what a diploid cell has two identical chromosomes that split and contain the same genetic material division of somatic cells to create new cells a type of cell that contains 23 pairs or a total of 46 chromosomes has a clear, distinct nucleus When an organism grows or repairs damaged tissue, new cells are created through a process called_____. 2. Your body has two types of cells: reproductive cells and _____cells that make up all the other body cells. 3. These cells have a distinct control center, or nucleus, which means they are _____. 4. Each nucleus contains the genetic code or _____for that organism. 5. Each human has 46 special genetic codes or _____that determine what characteristics we get from our parents. 6. A cell’s cycle begins with_____, a stage where the genetic information in chromosomes is copied. 7. Almost all of the cells in humans are _____which means having 46 chromosomes. 8. _____cells have only 23 chromosomes because they will combine with another set of 23 chromosomes during reproduction. 9. When each chromosome splits, the duplicates are called _____. 10. During interphase, the region of the chromosome where two are held together is called the_____. 23 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz After Viewing Quiz 3 Name Vocabulary Quiz B Choose the vocabulary word to make each statement correct. two small parts in animal cells that direct the movement of chromosomes during mitosis B. POLES opposite ends of a cell C. CYTOKINESIS when a cell’s cytoplasm divides and cuts the cell in half D. ANAPHASE third stage of mitosis; chromatids separate into chromosomes and spindle fibers pull them to opposite poles E. DUPLICATE to make an exact copy of F. NUCLEAR MEMBRANE envelope around nucleus of a cell G. PROPHASE first stage of mitosis; chromosomes become visible and centrioles move towards poles H. ALIGN to line up I. METAPHASE second stage of mitosis; nuclear membrane dissolves and chromatids align in center J. TELOPHASE fourth stage of mitosis; chromosomes at opposite poles, spindle fibers break down, and a nuclear envelope forms around both sets of chromosomes A. CENTRIOLES 1. The phase of mitosis where the nuclear membrane dissolves is the_____. 2. The envelope that surrounds the cell’s nucleus is the_____. 3. Another word to describe opposite ends of a cell is_____. 4. It is the function of the _____to assist the movement of chromosomes during mitosis. 5. During _____, the centrioles move towards opposite ends of the cell. 6. During _____, a cell is cut in half when the cytoplasm divides. 7. Before mitosis, each pair of chromosomes makes an exact copy or a_____. 8. It is during _____that new nuclear envelopes form around both sets of chromosomes. 9. During metaphase, the chromatids _____ at the center of the spindle. 10. Chromosomes move to opposite poles during _____. 24 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC Suggested Reading List Additional Resources Alberts, Bruce, Alexander Johnson, Julian Lewis, Martin Raff, Keith Roberts, and Peter Walter. Molecular Biology of the Cell. This book is a classic in-depth text reference in cell biology. The authors talk about the story of cell biology and help the non-expert reader create a framework to grasp the subject. The authors also explore the implications and possibilities that await us in the future. Written clearly and concisely, this beautifully illustrated book is a joy to read. Bowen, I. D., M. Bowen, and A. Jones. Mitosis and Apoptosis: Matters of Life and Death. This intriguing book takes a close look at the delicate balance between the birth and death of cells as well as the molecular processes involved in cellular cycles. Illustrated with line drawings and cartoons, this book is a treasure of information for young biologists. Klug, William and Michael Cummings. Concepts of Genetics. A clear writing style plus an emphasis on basic concepts makes this book very attractive to those interested in the world of genetics. Includes recent research and findings. Reider, Conly. Methods in Cell Biology, Volume 61: Mitosis and Meiosis. Mitosis and meiosis, those great processes for nuclear division in cells is the topic of this volume. It is a practical handbook that wraps itself around the modern technologies that are used to study these two processes. The author places an emphasis on the composition and function of centrosomes, spindle pole bodies, and kinetochore structure. Steingraber, Sandra. Living Downstream: A Scientist’s Personal Investigation of Cancer and the Environment. Application of scientific information to the real world, this book draws parallels from Rachel Carson’s work. It’s time to ask the big questions of the relationship between cancer and the environment. An important contribution to the future of cell biology. Thomas, Lewis. The Lives of a Cell: Notes of a Biology Watcher. This incredible collection of essays covers various biology subjects. Although the vocabulary can be challenging, the string of essays lead the reader through a stream of extremely interesting readings. 25 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz Internet Sites Additional Resources Below is a list of sites that you may use to find more information about mitosis. Due to routine web maintenance, not all of the links will be accurate at the time of access. If the link is not available, try to conduct a search on that topic from the main site or from a search engine. http://www.cellsalive.com/mitosis.htm Animal cell animation that demonstrates the stages of mitosis. Control buttons aid in running the animation. Click on intermediate stages for a representative still frame. http://www.accessexcellence.org/AB/GG/mitosis.html Graphics gallery that includes vocabulary. http://www.biology.arizona.edu/cell_bio/tutorials/cell_cycle/cells3.html Interesting tutorial site for studying cells, mitosis, meiosis, the cell cycle, prokaryotes, eukaryotes, & viruses. In English and Spanish. http://www.bio.unc.edu/faculty/salmon/lab/mitosis/mitosis.html Includes Mitosis World, Lab, Movies, Links, and Journals buttons. http://biology.nebrwesleyan.edu/benham/mitosis/ Colorful photographs of the stages of mitosis. http://www.bioweb.uncc.edu/biol1110/mitosis.htm Great outline format detailing the stages. http://www.microscopy.fsu.edu/micro/gallery/mitosis/mitosis.html Photo gallery. http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/M/Mitosis.html Stages of mitosis with electron microscope images. http://www.nature.com/ncb/celldivision/ Nature journal website. http://www.bioweb.uncc.edu/biol1110/Stages.htm Brilliant color photographs of stages of mitosis. http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/cell_division.html Interactive questions and answers about the process of mitosis. http://www.sci.sdsu.edu/multimedia/mitosis/navigator.html Features mitosis animations. 26 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC Answer Key - During Viewing Activity Sheet 1 Sequencing Wheel Graphic Organizer Complete the graphic organizer as you watch Mitosis Video Quiz video/DVD. Chromosomes replicate as the cell prepares for the next four stages of mitosis Nuclear membrane reappears; spindles disappear; two daughter cells form as cytoplasm divides; cytokinesis occurs The Mitosis Process One chromatid from each chromosome moves to poles of cell; there are now twice as many chromosomes in the cell as in parent cell Chromosomes become visible and attach to spindle fibers; nuclear membrane disappears Chromosomes are pulled by spindle fibers and line up in the center of the cell 27 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz Answer Key - During Viewing Activity Sheet 2 Stages Web What is mitosis? What are the stages? What happens during each stage? Complete this graphic organizer while viewing the Mitosis Video Quiz video/DVD. Definition of mitosis: Mitosis is cell division of somatic cells The stages: Prophase Purpose of mitosis: The purpose of mitosis is to create new cells for growth or tissue repair What occurs: Chromosomes become visible and attach to spindle fibers; nuclear membrane disappears Metaphase Chromosomes are pulled by spindle fibers and line up in center of cell Anaphase One chromatid from each chromosome moves to poles of cell; there are now twice as many chromosomes in the cell as in parent cell Telophase Nuclear membrane reappears; spindles disappears; two daughter cells form as cytoplasm divides; cytokinesis occurs 28 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC Answer Key - After Viewing Activity Sheet 1 The “What” Web Organizer After watching the Mitosis Video Quiz video/DVD, fill in the information missing from the following “what” questions below. • What is mitosis? Mitosis is cell division of somatic cells. • What is the purpose of this process? The purpose of mitosis is to create new cells for growth or tissue repair. • What happens before cell division can take place? Interphase is the first stage before cell division can begin. This is when the chromosomes replicate as the cell prepares for the next four stages of mitosis. • What are the stages of mitosis? After interphase the four stages of mitosis are prophase, metaphase, anaphase, and telophase. • What do chromosomes have to do with mitosis? The chromosomes are the genetic codes for each organism and it is through the stages of mitosis that the chromosomes are replicated. • What is the reason this process is so important to all life? All living things are made of cells. It is through the process of mitosis that new cells are created to replace old or damaged cells. 29 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz Answer Key - After Viewing Activity Sheet 3 Stages of Mitosis Name each stage of mitosis and write a brief description in the box of what takes place during that stage. Make a sketch of each stage in each of the circles. Stage: Prophase Description: Chromosomes become visible and attach to spindle fibers; nuclear membrane disappears Stage: Telophase Description: Stage:Metaphase Description: The Stages of Mitosis Nuclear membrane reappears; spindles disappear; two daughter cells form as cytoplasm divides; cytokinesis occurs Chromosomes are pulled by spindle fibers and line up in center of cell Stage: Anaphase Description: One chromatid from each chromosome moves to the poles of the cell; there are now twice as many chromosomes in the cell as in parent cell 30 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC Answer Key - After Viewing Activity Sheet 4 Cell Division Match the different steps of cell division with the correct label. cell division parent cell cell growth daughter cells Draw the steps in the proper order. Label each. The last step has been completed for you. Then, write a summary statement about this process. parent cell Summary: cell growth cell division daughter cells Answers may vary but should include the key concepts of mitosis being the process of cell division as cells go from a parent cell, through a period of growth, then cell division, and finally ending as new daughter cells. 31 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz Answer Key - After Viewing Quiz 1 Mitosis Quiz Mark the correct answer. 1. Mitosis: a. Takes place only in brain tissue b. Is how cells reproduce and tissues grow c. Divides only the cell nucleus d. Creates cells that are different from each other 2. Human haploid cells have: a. 23 pairs of chromosomes b. 46 chromosomes c. 23 chromosomes d. A and B 3. True or False: Mitosis is the division of somatic cells to create new, identical cells. 4. Humans have _____chromosomes in their somatic cells. a. 47 b. 46 c. 23 d. 48 5. A eukaryotic cell has: a. No nucleus b. A distinct nucleus c. An indistinct nucleus d. Two nuclei 6. Chromosomes are made of: a. Sugar and spice b. DNA molecules c. DNA and cytoplasm d. The liquid from the cell 7. Chromatids are joined together at a point called the ___________. a. Center point b. Middle c. Nucleus d. Centromere 32 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC Answer Key - After Viewing Quiz 1 Mitosis Quiz (cont.) 8. Diploid cells have: a. 23 pairs of chromosomes b. 46 chromosomes c. 23 chromosomes d. A and B 9. The genetic information for an organism is found: a. In the cell nucleus b. In the cytoplasm c. In the cell membrane d. All of the above 10. The cytoplasm: a. Is a thick liquid b. Is another name for the nucleus c. Holds many of the cell’s organelles d. A and C 11. During Prophase, the centrioles: a. Join together b. Move to center of cell and form 2 separate poles c. Move to opposite ends of cell and form 2 separate poles d. None of the above 12. The four stages of mitosis in their correct order are: a. Prophase, metaphase, anaphase, telophase b. Prophase, telophase, anaphase, metaphase c. Anaphase, prophase, metaphase, telophase d. Telophase, metaphase, anaphase, prophase 13. True or False: In plants and animals, the cell membrane pinches the divided cell mass into two cells. 14. The chromosomes are pulled apart by the spindle fibers during which stage: a. Anaphase b. Interphase c. Telophase d. Prophase 33 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz Answer Key - After Viewing Quiz 1 Mitosis Quiz (cont.) 15. During interphase: a. The cell grows b. Chromosomes start to duplicate c. The cell prepares for mitosis d. All of the above 16. During metaphase: a. The chromosomes duplicate b. The spindle fibers attach to the centromere c. The cell membrane closes around the new cells d. The chromatids split at the centromere 17. True or False: During metaphase, the nuclear membrane finishes breaking down. 18. In which stage do the nuclear envelopes form around the separate sets of chromosomes: a. Anaphase b. Interphase c. Telophase d. Prophase 19. After a. b. c. d. mitotic cell division, or mitosis, the daughter cells contain: Half of the chromosomes of the parent cell The same number of chromosomes as the parent cell A random number of chromosomes An unknown number of chromosomes 20. What structure inside the cell helps pull the chromatids apart: a. Centromere b. Spindle Fibers c. Nucleus d. Membrane 34 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC Answer Key - After Viewing Quiz 2 Vocabulary Quiz A Choose the vocabulary word to make each statement correct. 1. A. DNA B. INTERPHASE C. D. E. F. CENTROMERE CHROMOSOMES SOMATIC HAPLOID G. CHROMATIDS H. I. MITOSIS DIPLOID J. EUKARYOTIC deoxyribonucleic acid; the unique genetic code for every living thing a stage of mitosis during which exact copies of chromosomes are made a single point where two chromatids are held together strands of genetic codes made up of DNA molecules any cell that is not a reproductive cell a type of cell that contains a total of 23 chromosomes, half of what a diploid cell has two identical chromosomes that split and contain the same genetic material division of somatic cells to create new cells a type of cell that contains 23 pairs or a total of 46 chromosomes has a clear, distinct nucleus When an organism grows or repairs damaged tissue, new cells are created through H a process called_____. 2. E Your body has two types of cells: reproductive cells and _____cells that make up all the other body cells. 3. J These cells have a distinct control center, or nucleus, which means they are_____. 4. A Each nucleus contains the genetic code or _____for that organism. 5. D Each human has 46 special genetic codes or _____that determine what characteristics we get from our parents. 6. B a stage where the genetic information in A cell’s cycle begins with_____, chromosomes is copied. 7. I Almost all of the cells in humans are _____which means having 46 chromosomes. 8. F _____cells have only 23 chromosomes because they will combine with another set of 23 chromosomes during reproduction. 9. G When each chromosome splits, the duplicates are called _____. 10. During interphase, the region of the chromosome where two are held C together is called the_____. 35 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz Answer Key - After Viewing Quiz 2 Vocabulary Quiz B Choose the vocabulary word to make each statement correct. two small parts in animal cells that direct the movement of chromosomes during mitosis B. POLES opposite ends of a cell C. CYTOKINESIS when a cell’s cytoplasm divides and cuts the cell in half D. ANAPHASE third stage of mitosis; chromatids separate into chromosomes and spindle fibers pull them to opposite poles E. DUPLICATE to make an exact copy of F. NUCLEAR MEMBRANE envelope around nucleus of a cell G. PROPHASE first stage of mitosis; chromosomes become visible and centrioles move towards poles H. ALIGN to line up I. METAPHASE second stage of mitosis; nuclear membrane dissolves and chromatids align in center J. TELOPHASE fourth stage of mitosis; chromosomes at opposite poles, spindle fibers break down, and a nuclear envelope forms around both sets of chromosomes A. CENTRIOLES I 1. The phase of mitosis where the nuclear membrane dissolves is the_____. F 2. The envelope that surrounds the cell’s nucleus is the_____. B 3. Another word to describe opposite ends of a cell is_____. A 4. It is the function of the _____to assist the movement of chromosomes during mitosis. G the centrioles move towards opposite ends of the cell. 5. During _____, C a cell is cut in half when the cytoplasm divides. 6. During _____, E 7. Before mitosis, each pair of chromosomes makes an exact copy or a_____. J 8. It is during _____that new nuclear envelopes form around both sets of chromosomes. H at the center of the spindle. 9. During metaphase, the chromatids _____ D 10. Chromosomes move to opposite poles during _____. 36 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC Script CAST Professor Science ....................................................host Ricky Wave ................................................................DJ Star Stuck ............................................................reporter Salty Gales ............................................................pirate Quizitor ....................................................................robot Victor Velocity............................................racecar driver Sandy Space ....................................................astronaut Nuke Rockney ......................................................coach Quiz Clown ............................................................clown Wendy River ........................................................cowgirl Fizzle ........................................................................genie SCENE 1 PROFESSOR SCIENCE Hello there! Welcome to another wacky episode of the Wonderful World of Science, starring… Me, PROFESSOR SCIENCE!! Do I have a great show for you today! We are going to explore the amazing world of cell division, mitosis, to be exact!! So let’s dive into this whole mitosis thing and see what is happening! You see, every living thing is made of cells. Every living thing goes through mitosis in order to grow. Trees, cats, elephants, and humans all undergo mitosis. When an organism grows, the cells don’t keep getting bigger and bigger; they multiply. The body has to create new cells to make bigger bone, muscle and skin tissues! New cells are also created to repair our tissues. The cells in our body don’t last forever, you know. Whoa! What did I just say? The cells in our body don’t last forever!?! That sounds pretty scary, doesn’t it? Well, it’s really not. Our bodies constantly replace old or damaged cells with new ones. Like when you cut your finger, new cells are created to replace the damaged ones. 37 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz Script These tissue cells are called somatic. They are the basic unit that makes up our body tissues and organs. When these cells divide, the process is called mitosis. Mitosis is the division of somatic cells to create new, identical cells. During mitosis, the cell divides to make two cells. And two cells divide to make four, and four make eight, and eight . . . Alright. Let’s talk about the cell. Each cell has parts: a nucleus that controls the cell function, organelles outside of the nucleus that perform specialized tasks, cytoplasm to hold the organelles in place, and a cell membrane that separates the cell from other cells, and lets nutrients in and waste out. Did you know that cells have cycles? Different cell types have different cycles. And not all cells reproduce. Nerve cells aren’t replaced once they become mature. Some cells have a faster division rate than others. And mitotic rates vary slightly among people, depending on one’s diet and age. This is why some people’s hair and nails grow faster than others. Check this out! A bacteria cell, E. coli, reproduces every thirty minutes! A sea urchin has cells that double every two hours. Human cells divide much slower than that. Adult skin cells, like right here on my arm, divide about once every 24 hours! A cell’s cycle begins with a stage called interphase. During this stage, the organelles produce energy and proteins to grow and build new cells. The organelles duplicate themselves during interphase. Also during this phase, the genetic material in the nucleus is duplicated. Next, the cell undergoes mitosis! A cell’s cycle is completed in the final stages of mitosis, when the cytoplasm divides and the cell membranes form around the two new cells. SCENE 2 PROFESSOR SCIENCE Before we examine the stages of mitosis, or the actual division of a cell, it is probably a good idea to know what is in the cell that is dividing. A somatic cell is a typical body cell, like a skin, hair, or lung cell. It’s eukaryotic, meaning it has a distinct nucleus. The nucleus is kind of like a brain; it controls everything the cell does. The nucleus contains the DNA, or deoxyribonucleic acid. 38 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC Script DNA is our genetic code. This code is different for each person in the whole world! That’s right! You are the only person in the entire world with your genetic code, unless, of course, you have an identical twin! DNA molecules join together to make up a complex strand called a chromosome. Now, somatic cells have a certain number of chromosomes inside their nuclei, depending on what organism it is. The number of chromosomes differs for each type of organism Pea plants have 14; humans have 46; gorillas have 48, and goldfish have 94 chromosomes in each cell. Notice that all of these numbers are even. That’s because our chromosomes exist in pairs. Humans have 23 pairs of chromosomes or a total of 46. Of each pair, one chromosome comes from our mother and the other from our father. Now, the number of chromosomes in a cell is very important. Somatic cells in humans must have 23 pairs of chromosomes, or a total of 46. This type of cell is called a diploid cell, because it has the full number of chromosomes. Almost all of the cells in the human body are diploid. The rest are haploid cells, with only one chromosome from each pair. Haploid cells are produced for organism reproduction through a cell division called meiosis. But that’s another show, completely. Now, in the cell cycle, chromosomes actually start out as long thin strands, or chromatin, which is like a ball of tangled thread. During interphase, the chromosomes duplicate. When mitosis begins, the chromatin condense and break up into short pieces that are chromosomes. This is what a chromosome looks like at this stage. The duplicated chromosomes join together at a single point called the centromere, and at this stage they are called chromatids. Now we’re ready to study the phases of mitosis. Remember, every cell in our body has identical chromosomes, which are made from DNA molecules. This is all because of mitosis! Isn’t that amazing? Well, I think you are ready to tackle your first set of questions. Take it away guys! 39 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz Script SCENE 3 RICKY WAVE Hey, I’m glad you tuned in. This is DJ Ricky Wave broadcasting the first question from SQRD- science quiz radio. And away we gooooo! 1. Mitosis: a. Takes place only in brain tissue b. Is how cells reproduce and tissues grow c. Divides only the cell nucleus d. Creates cells that are different from each other How did you do? Get that answer on paper and we’re movin’ and groovin’ to the next question! See you on the flip side! STAR STRUCK Hello movie fans, this is Star Struck coming to you live from the latest big movie star premiere. I’m excited to be here and I hope you are ready because it’s time for… 2. Human haploid cells have: a. 23 pairs of chromosomes b. 46 chromosomes c. 23 chromosomes d. A and B Any luck? Write those answers down. Hang in there! That’s what I tell all the super stars! SALTY GALES Ahoy! Salty Gales here. I’ve just come back from a grand adventure. Maybe someday I’ll tell ye all about it. But first, here’s the next question… 3. True or False: Mitosis is the division of somatic cells to create new, identical cells Well, what do you think? Be sure to write your answer down. Well, the seven seas are calling me again so I’m shipping out! 40 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC Script QUIZITOR Hello. I am Quizitor. I hope you are doing well so far. Let’s get connected and download the next question. 4. Humans have _____chromosomes in their somatic cells. a. 47 b. 46 c. 23 d. 48 This is a fill-in-the- blank question so pick a number and write it down. It’s time for me to juice up my circuits. VICTOR VELOCITY Vroom, vroom! Oh hello, there! Just let me make this turn…. All right, while we’re in the open stretch, here’s a question to test the ability of your knowledge! 5.A eukaryotic cell has: a. No nucleus b. A distinct nucleus c. An indistinct nucleus d. Two nuclei How did you do? Write down your answer before I speed away on my next lap! SANDY SPACE Hello from the Space Station. I’m Sandy Space. 6. Chromosomes are made of: a. Sugar and spice b. DNA molecules c. DNA and cytoplasm d. The liquid from the cell So how did you do? Did you get an answer down? Good. Don’t float away because the next question is coming up. 41 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz Script NUKE ROCKNEY All right team, way to retain that knowledge! (Blows whistle) Time for a quick drill! 7. Chromatids are joined together at a point called the _______. a. Center point b. Middle c. Nucleus d. Centromere Hmm. That’s interesting. Pick one and write it down- you have a 50-50 chance. It’s not whether you win or lose it’s how you play the game! QUIZ CLOWN (Trying to juggle) You wouldn’t believe how hard this is! Before I get back to practicing, try this out! 8. Diploid cells have: a. 23 pairs of chromosomes b. 46 chromosomes c. 23 chromosomes d. A and B What’s your answer? Write it down. Well, I’ve got to keep on juggling. The head clown is testing me later! WENDY RIVER Howdy, y’all! I thought I’d see if you could wrangle up the correct answer to this question for me! 9. The genetic information for an organism is found: a. In the cell nucleus b. In the cytoplasm c. In the cell membrane d. All of the above So how’d you do? Get your answer on paper and let’s mosey on to the next question! 42 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC Script FIZZLE Hi there! You won’t need three wishes if you know the answer to this! 10. The cytoplasm: a. Is a thick liquid b. Is another name for the nucleus c. Holds many of the cell’s organelles d. A and C I wish I could help you on that one. But I’m sure you don’t need it. You already have an answer down, right? Great! Now on to more fun and excitement with Professor Science! SCENE 4 PROFESSOR SCIENCE Welcome back! I bet you plowed right through those questions! Now that we know about the cell cycle, and what happens to chromosomes before mitosis begins, it’s time to learn the different phases of Mitosis and see how this stuff really works! When discussing Mitosis, scientists refer to the original cell as the parent cell, and the new cells as daughter cells. The pairs of chromosomes from the original cell are sister chromosomes, the duplicate ones are daughter chromosomes. Interphase is the longest phase in the cell cycle because there are many things the cell must do to prepare for mitosis. During interphase, the cell grows and DNA duplicates. After this happens, the cell is ready to divide. There are FOUR stages to Mitosis: Prophase, Metaphase, Anaphase, and Telophase. It is in Prophase that the chromatin goes from a tangled ball to individual, condensed chromosomes. Animal cells have centrioles that move to opposite ends of the cell and form distinct poles. Plant cells do not have centrioles, but are still able to accurately divide. The centrioles produce tiny fibers that span across the cell between the two poles. This forms a spindle. The cell is shaped like a football at this point. Next, the cell’s nuclear membrane begins to break down. 43 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz Script The second stage is Metaphase. At this stage, the nuclear membrane finishes dissolving, and the chromatids align at the center of the cell. The spindle fibers attach to each centromere. The chromatids are most compact at the end of Metaphase. During Anaphase, the chromatids separate into chromosomes when the spindle fibers pull them apart at the centromere. Each identical set of new chromosomes moves to opposite sides of the cell, or the poles. At the start of Telophase, the chromosomes are at opposite poles and the spindle fibers break down. The chromosomes elongate and become tangled in a ball of chromatin again. A nuclear envelope forms around the separate sets of chromosomes. Now, remember, since the 46 chromosomes duplicate right before mitosis takes place, each new cell has an identical set of 46 chromosomes, or 23 pairs. SCENE 5 PROFESSOR SCIENCE Now it’s time to divide the rest of the cell. The cytoplasm, cell membrane, and organelles were duplicated earlier during interphase. In animal cells, the cytoplasm divides as the cell membrane pinches inward, cutting the cell in half. This is called cytokinesis. Fully divided, there are now two daughter cells completely independent of each other. Each cell has its own nucleus with identical DNA, cytoplasm, cell membrane, and organelles. These new cells each start interphase where they will grow until they are ready to divide. Then, mitosis will begin all over again. Cells separate a little differently in plants than in animals. The wall of a plant cell is more stiff and rigid than an animal’s cell membrane. Rather than moving inward, a cell plate forms in the center of the two dividing cells. The plate is made of hard cellulose deposits, which develops outward until the two cells are completely separate. A cell wall for each cell stems from the cell plate. 44 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC Script And there you have it, folks! Cell division by Mitosis! Don’t forget how important cell division is! Cell division is the process that enables plants, animals and other eukaryotes to reproduce and grow. Pretty cool, isn’t it? With all this information fresh in your brains, my friends are going to come back out to see what you know! SCENE 6 SALTY GALES Batton down the hatches, all of yee- a storm’s a brewin’! Ahoy matie. Time again for ole Salty here to give you another question. 11. During Prophase, the centrioles: a. Join together b. Move to center of cell and form 2 separate poles c. Move to opposite ends of cell and form 2 separate poles d. None of the above Whew! Did you catch all that? Remember to write down yer answer. I’ve got to see if my crew battoned down those hatches! STAR STRUCK Hi everyone, Star Struck here with the latest entertainment news. Ooops! Sorry, I mean the latest science quiz question. 12. The four stages of mitosis in their correct order are: a. Prophase, metaphase, anaphase, telophase b. Prophase, telophase, anaphase, metaphase c. Anaphase, prophase, metaphase, telophase d. Telophase, metaphase, anaphase, prophase Well, there’s starphase and moviephase…just kidding. I’m sure you know all of them. Just write those phases down before the next question comes up! 45 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz Script SANDY SPACE Wow! That asteroid was too close for comfort. Hi, Sandy Space bringing you the next cell-estial science question! 13. True or False: In plants and animals, the cell membrane pinches the divided cell mass into two cells. Hmm. Good question. You know the answer, right? Just write it down and we’ll be moving along. I’ve gotta go maneuver through this asteroid belt. QUIZITOR Hello. I am Quizitor. It is time again for another question. I hope you are ready. Here we go! 14. The chromosomes are pulled apart by the spindle fibers during which stage: a. Anaphase b. Interphase c. Telophase d. Prophase What do you think? Use a writing utensil and a piece of paper to mark your response. Thank you for stopping by; it’s time for me to go oil my sprockets. VICTOR VELOCITY Vroom, vroom! Eeeerch!!! Thought I’d make a quick pit stop and spin a question out to you! 15. During interphase: a. The cell grows b. Chromosomes start to duplicate c. The cell prepares for mitosis d. All of the above Don’t rush through that one. Pick an answer and write it down. Oh, I see the flag going down. I’ve gotta run! 46 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC Script RICKY WAVE Hi everyone from SQRD- science quiz radio. It’s me Ricky Wave. I’m here to continue the countdown of the top 20 mitosis questions. This one has had major radio play…it’s a big hit in Europe.. it’s 16. During metaphase: a. The chromosomes duplicate b. The spindle fibers attach to the centromere c. The cell membrane closes around the new cells d. The chromatids split at the centromere So, what do you think? Does it make the cut? Write down your choice and keep listening to the wonderful tunes of SQRD! NUKE ROCKNEY All right team, we’ve been practicing for this moment! (Blows whistle) Now get out there and show them what you’re made of! 17. True or False: During metaphase, the nuclear membrane finishes breaking down. How did it go? It’s a 50-50 chance. So take it! Write down an answer and keep on moving. Go team go! QUIZ CLOWN (Trips on feet) I haven’t quite got the hang of these big shoes yet! While I dust myself off, see if you can do any better with this! 18. In which stage do the nuclear envelopes form around the separate sets of chromosomes: a. Anaphase b. Interphase c. Telophase d. Prophase What do you think? Write down an A, B, C, or D. I’m going to give these big shoes another try. Clown College was never like this! 47 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz Script WENDY RIVER Yee-haw!! I love these broncs! Why don’t y’all test your skills on this one here! 19. After mitotic cell division, or mitosis, the daughter cells contain: a. Half of the chromosomes of the parent cell b. The same number of chromosomes as the parent cell c. A random number of chromosomes d. An unknown number of chromosomes Before I ride off into the sunset, make sure you’ve got an answer down. See y’all at the next round-up! FIZZLE Hi there! Before I return to my bottle, a wish was used to see if you’ve been paying attention! 20. What structure inside the cell helps pull the chromatids apart: a. Centromere b. Spindle Fibers c. Nucleus d. Membrane We’ve reached the end! Did you get the last answer on paper? Great! Now back to Professor Science while I return to my home sweet home. SCENE 7 PROFESSOR SCIENCE Well folks, there you have it, all you need to know about the amazing cell division process called mitosis! Coming up are the answers to the questions my friends gave you! Now I gotta split! I’ll see you next time on the Wonderful World of Science!! 48 Mitosis Video Quiz © Sunburst Visual Media, a division of Global Video, LLC Script ANSWERS 1. b. Mitosis is how cells reproduce and grow. 2. c. 23 chromosomes 3. True. Mitosis is the division of somatic cells to create new, identical cells. 4. b. Humans have 46 chromosomes in their somatic cells. 5. b. An eukaryote has a distinctive nucleus. 6. b. Chromosomes are made of DNA molecules. 7. d. centromere 8. d. Diploid cells have 23 pairs of chromosomes or 46 single chromosomes. 9. a. The genetic information for an organism is found in the cell nucleus. 10. d. The cytoplasm is the living substance of the cell, the cell membrane. 11. c. During prophase, the centrioles, if there are any, move to opposite ends of the cell and form 2 separate poles. 12. a. Prophase, Metaphase, Anaphase, Telophase 13. False. Plants have a hard cell plate that grows in the middle to split the two cells.. 14. a. The sister chromosomes split completely in anaphase. 15. d. During interphase, the cell grows, chromosomes start to duplicate, and the cell prepares for mitosis. 16. b. The spindle fibers attach to the centromeres. 17. True. 18. c. The nuclear envelopes form around the separate cells during telophase. 19. b. After mitotic cell division, the daughter cells contain the same number of chromosomes as the parent cell. 20. b. The spindle fibers pull the chromosomes apart. During metaphase, the nucleus is completely broken up. 49 © Sunburst Visual Media, a division of Global Video, LLC Mitosis Video Quiz
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