Skills Worksheet Test Prep Pretest In the space provided, write the letter of the term or phrase that best completes each statement or best answers each question. 1. As a cell prepares to divide, a DNA molecule and its associated proteins coil to form a a. chromatid. b. gene. c. chromosome. d. centromere. 2. What is the number of chromosomes found in a human body cell? a. 23 c. 48 b. 46 d. 64 3. The sex of a human offspring is determined by a. the female. b. the male. c. both the female and the male. d. neither the female nor the male. 4. Bacteria reproduce through an asexual process called a. meiosis. b. cytokinesis. c. interphase. d. binary fission. 5. In plant cells, cytokinesis requires the formation of a new a. Golgi apparatus. b. cell wall. c. centromere. d. series of protein threads. 6. Gene mutations that result in cancer often cause the a. overproduction of growth-promoting proteins. b. underproduction of growth-promoting proteins. c. activation of control proteins that slow or stop the cell cycle. d. Both (a) and (c) 7. Which of the following is NOT part of the spindle apparatus in animal cells? a. microtubules c. spindle fibers b. belt of protein threads d. centrioles Holt Biology 21 Chromosomes and Cell Reproduction
Test Prep Pretest continued Complete each statement by writing the correct term or phrase in the space provided. 8. A(n) is a segment of DNA that transmits information from parent to offspring. 9. An individual with an extra copy of chromosome 21 demonstrates traits collectively known as. 10. The 22 pairs of chromosomes in human somatic cells that are the same in males and females are called. 11. The human chromosomes that determine an individual s sex are called the. Questions 12 17 refer to the sequence below. G 1 S G 2 M C 12. The sequence above represents the. 13. The S in the sequence represents the phase in which occurs. 14. Phases G 1, S, and G 2 in the sequence above are collectively called. 15. Each individual protein structure that helps to move the chromosomes apart during mitosis is called a(n). 16. A disease caused by uncontrolled cell division is. 17. In the first stage of binary fission, the DNA is. Read each question, and write your answer in the space provided. 18. What happens to the structure of DNA in your cells prior to cell division? Holt Biology 22 Chromosomes and Cell Reproduction
Test Prep Pretest continued 19. Explain the difference in the number of chromosomes between a frog somatic cell and a frog egg cell. 20. What happens when nondisjunction takes place during cell division? 21. Describe what happens at each checkpoint during the cell cycle. 22. What are the four stages of mitosis in the correct order? 23. Explain the events that take place during each stage of mitosis. Holt Biology 23 Chromosomes and Cell Reproduction
Test Prep Pretest continued 24. Describe the events that take place during each phase of interphase. 25. List four types of events that take place in a eukaryotic organism, such as a deer, that require cell division. Holt Biology 24 Chromosomes and Cell Reproduction
TEACHER RESOURCE PAGE SECTION: THE CELL CYCLE 1. cell cycle, interphase 2. cell cycle: repeating sequence of growth and division during the life of a cell; interphase: first three phases of the cell cycle 3. It is in the process of dividing. 4. d 5. a 6. e 7. c 8. a 9. d 10. b 11. c 12. b 13. a 14. d 15. Both are phases of the cell cycle in which a cell part divides. However, during mitosis, a nucleus divides, while during cytokinesis, cytoplasm divides. 16. d SECTION: MITOSIS AND CYTOKINESIS 1. p 5. b 2. b 6. p 3. a 7. d 4. p Vocabulary Review 1. c 11. b 2. a 12. c 3. b 13. b 4. d 14. a 5. c 15. b 6. d 16. c 7. a 17. a 8. c 18. c 9. a 19. d 10. b Concept Mapping 1. prokaryotes 2. eukaryotes 3. growth 4. repair 5. asexual reproduction 6. sexual reproduction 7. first growth phase 8. synthesis phase 9. second growth phase 10. cytokinesis (Items 3 6 are interchangeable. Items 7 10 are interchangeable.) Science Skills SEQUENCING 1. b 2. e 3. g 4. a 5. d 6. h 7. c 8. f 9. anaphase 10. telophase 11. metaphase 12. prophase 13. 3 14. 2 15. 4 16. 1 Critical Thinking 1. a 14. b 2. d 15. a 3. e 16. f 4. b 17. b, f 5. c 18. i, d 6. e 19. j, h 7. a 20. g, a 8. c 21. c, e 9. d 22. c 10. b 23. c 11. d 24. b 12. e 25. a 13. c Test Prep Pretest 1. c 2. b 3. b 4. d 5. b 6. a 7. b 8. gene 9. Down syndrome 10. autosomes 11. sex chromosomes Holt Biology 83 Chromosomes and Cell Reproduction
TEACHER RESOURCE PAGE 12. cell cycle 13. DNA synthesis 14. interphase 15. microtubule 16. cancer 17. copied 18. Prior to cell division, the DNA and proteins associated with the DNA coil into structures called chromosomes. 19. A frog somatic cell is diploid and therefore has twice the number of chromosomes of the haploid frog egg cell. 20. When one or more chromosomes fail to separate properly during cell division in gamete production, one new cell will receive both chromosomes, and the other new cell will receive none. As a result, one gamete will be produced that has one extra chromosome, and another gamete will be produced that is missing one chromosome. 21. If conditions are favorable for cell division during the first growth phase, certain proteins will stimulate the cell to begin the synthesis phase, during which DNA is duplicated. During the second growth phase, the DNA replication is checked by DNA repair enzymes. If everything is in order, proteins then initiate the beginning of mitosis. At the final checkpoint, the cell is prompted to exit from the mitosis phase and to begin the first growth phase again. 22. prophase, metaphase, anaphase and telophase 23. During prophase, chromosomes coil up and become visible, the nuclear envelope dissolves, and the spindle apparatus forms. During metaphase, the chromosomes line up in the center of the cell. During anaphase, the centromeres divided and the chromatids are drawn to opposite poles by spindle fibers. During telophase, a nuclear envelope forms around the chromosomes at each pole. The chromosomes uncoil, and the spindle dissolves. 24. The phases of interphase are the first growth (G 1 ) phase, the synthesis (S) phase, and the second growth (G 2 ) phase. The G 1 phase is the growth phase of a cell when the cell grows rapidly and carries out its routine functions. DNA is copied during the S phase. In the G 1 phase, preparations are made for nuclear division. Proteins needed for cell division are synthesized. 25. growth, development, repair, reproduction Quiz SECTION: CHROMOSOMES 1. d 6. c 2. b 7. b 3. e 8. c 4. c 9. b 5. a 10. d SECTION: THE CELL CYCLE 1. d 6. b 2. e 7. a 3. b 8. c 4. a 9. b 5. c 10. b SECTION: MITOSIS AND CYTOKINESIS 1. e 6. c 2. a 7. b 3. d 8. d 4. c 9. a 5. b 10. d Chapter Test (General) 1. f 11. d 2. e 12. b 3. h 13. c 4. i 14. c 5. a 15. b 6. c 16. d 7. d 17. a 8. g 18. d 9. j 19. a 10. b 20. d Holt Biology 84 Chromosomes and Cell Reproduction