Name Class Date Skills Worksheet Meiosis SEQUENCING/ORGANIZING INFORMATION In the space provided in the figure below, write the letter of the stage of meiosis from the list below (a–h) that matches each stage in the figure. 1. _________ 5. _________ 2. _________ 6. _________ 3. _________ 7. _________ 4. _________ 8. _________ Stages of Meiosis a. anaphase II e. telophase II and cytokinesis b. metaphase I f. telophase I and cytokinesis c. anaphase I g. prophase I d. metaphase II h. prophase II Copyright © by Holt, Rinehart and Winston. All rights reserved. Holt Science: Biology 13 Science Skills Worksheets Name Class Date Meiosis continued In the space provided, write the letter of the description that best matches the stage of meiosis. ______ 9. metaphase I ______10. prophase II ______11. telophase I ______12. metaphase II ______13. telophase II ______14. anaphase II ______15. prophase I ______16. anaphase I a. A new spindle forms around the chromosomes. b. Chromatids remain attached at their centromeres as the spindle fibers move the homologous chromosomes to opposite poles of the cell. c. A nuclear envelope forms around each set of chromosomes, the spindle breaks down, and the cytoplasm divides, resulting in four haploid cells. d. Chromosomes gather at the poles; the cytoplasm divides. e. The nuclear envelope breaks down; genetic material is exchanged through crossing-over. f. Chromosomes line up at the equator. g. Pairs of homologous chromosomes line up at the equator. h. Centromeres divide, enabling the chromatids, now called chromosomes, to move to opposite poles of the cell. Copyright © by Holt, Rinehart and Winston. All rights reserved. Holt Science: Biology 14 Science Skills Worksheets TEACHER RESOURCE PAGE Cell Transport Meiosis PREDICTING SEQUENCING/ORGANIZING INFORMATION 1. Thirty grams of substance A will be in solution on side 1, and 30 g will be in solution on side 2. Because the membrane is permeable to substance A, diffusion will take place. Molecules of substance A will move from the side of the membrane where they are less concentrated until equilibrium is reached. 2. The original 20 g of substance B will remain in solution on side 1, and the original 40 g will remain in solution on side 2 because substance B cannot pass through the membrane. 3. The water level will be higher on side 2 of the U-tube. As substance A molecules move across the membrane from side 1 to side 2, there will be more dissolved molecules on side 2 than on side 1. This will cause water to move across the membrane by osmosis from side 1 to side 2. 4. The cells will swell and will take in water until they and the flask solution are isotonic. 5. The cells will remain the same size because the solutions are isotonic. 6. The cells will shrink, and water will move out of the cells until they and the flask solution are isotonic. 1. 2. 3. 4. 5. 6. 7. 8. ANALYZING EXPERIMENTS 1. a. R i. R b. R j. r c. r k. R d. Rr l. RR e. Rr m. Rr f. r n. r g. Rr o. Rr h. Rr p. rr 2. Only one phenotype is present—plants with round seeds; only one genotype is present—Rr. 3. There are two phenotypes present— round seeds and wrinkled seeds. They are present in the ratio of three with round seeds to one with wrinkled seeds. 4. Mendel’s hypothesis is supported by this analysis. When both the R and r alleles appeared together, only the dominant phenotype was expressed (round seeds). 5. Mendel probably did not observe an exact ratio of 3:1. These numbers represent probabilities. For example, there is a 75 percent chance that any one offspring will have the round phenotype. Assuming Mendel obtained large numbers of offspring to analyze, he would have calculated a ratio of approximately 3:1. SEQUENCING b e g a anaphase telophase metaphase prophase 3 2 4 1 5. 6. 7. 8. g a d f c h e b Genetics Cell Cycle and Mitosis 1. 2. 3. 4. 9. 10. 11. 12. 13. 14. 15. 16. 9. 10. 11. 12. 13. 14. 15. 16. g b c f h d a e d h c f Copyright © by Holt, Rinehart and Winston. All rights reserved. Holt Science: Biology 92 Science Skills Worksheets Answer Key