Study Guide Answers

Name: ______________________ Date _____ Unit 7 Study Guide: Meiosis, Asexual Reproduction, and Lifecycles •

Meiosis • BE SURE YOU KNOW WHAT HAPPENS DURING EACH STAGE! 1. What is the process in which one diploid cell produces 4 haploid cells? Meiosis 2. At the end of meiosis how many genetically different cells are produced? 4 genetically different cells 3. How many divisions of the nucleus are in meiosis? What are they called? There are 2 divisions, meiosis I and meiosis II 4. What happens in prophase I? Chromosomes condense, nuclear envelope breaks down, homologous chromosomes pair up and cross over 5. What is crossing over, when does it occur, and why is it important? Occurs in prophase, one portion of each chromatid is exchanged, causes genetic recombination 6. What happens in metaphase I Homologous chromosomes move to the middle of the cell 7. What happens in anaphase I? Homologous chromosomes separate 8. When does the cell go from diploid to haploid? Anaphase I or telophase I of meiosis I 9. What happens in telophase I? Chromosomes gather at poles, nuclear envelope forms, cytoplasm divides 10. At the end of meiosis I, how many cells are there and are they haploid or diploid? 2 haploid 11. Do the centromeres divide in anaphase I? No 12. What happens during prophase II? New spindles form 13. What happens during metaphase II? Chromosomes align in center, spindle fibers attach to centromeres 14. What happens during anaphase II? Centromere divides, chromatids move to opposite poles 15. What happens during telophase II? Nuclear envelope forms

Name: ______________________ Date _____ 16. What is independent assortment and why is it important? Each pair of chromosomes separate independently; causes multiple gametes to be produced 17. What is random fertilization and why is it important? A lot of different possibilities for the gamete combination of the zygote 18. What is spermatogenesis? Formation of sperm cells 19. What is oogenesis? Formation of egg cells 20. When do homologous chromosomes separate? Anaphase I 21. When do homologous chromosomes move to the center of the cell? Metaphase I 22. What is the difference between anaphase I and anaphase II? Anaphase I separates homologous chromosomes; anaphase II separates chromatids Asexual Reproduction: 1 – What is Sexual Reproduction? How many parents are needed for this process to occur? Process by which organisms produce more of their own kind; 2 parents 2 – What types of cells merge together to form a diploid cell in sexual reproduction? What is that diploid cell called? 2 haploid gametes; zygote 3 – What is the difference between the life cycles of Plant and Animals? Plants exist in 2 forms and have 2 parts to their life cycle --> alteration of generations - What are the Haploid Cells in a Plant called? __gametophyte - What are the Diploid Cells in a Plant called? __sporophyte 4 – What is Asexual Reproduction (Hint – how many parents?) reproduction with only 1 parent 5 – True or False: In Asexual Reproduction, the offspring are genetically identical to their parents. true 6 – List five types of Asexual Reproduction: mitosis binary fission budding fragmentation parthenogenesis vegetative propagation 7 – Describe what happens in Mitosis. Are the cells Haploid or Diploid? Exact duplication of nucleus to form 2 identical nuclei; diploid 8 – Describe what happens in Binary Fission. Give an example of an organism that reproduces this way.

Name: ______________________ Date _____ Occurs in single celled organisms, nucleus divides by mitosis and cytoplasm divides 9 – Describe what happens in Budding. What part of the cell is smaller than the parent in this process? New individuals split off from the parent the bud is the part that splits off 10 – Describe what happens in Fragmentation. Body breaks apart 11 – Describe what happens in Parthenogenesis. Unfertilized eggs develop into new individuals 12 – Describe what happens in Vegetative Propagation. What parts can a new plant develop from? (plants only) new plants develop from roots, stems, or leaves of a parent plant 13 – List one advantage and one disadvantage for sexual reproduction and one advantage and one disadvantage for asexual reproduction. Asexual Advantage: produce a lot of offspring in short period of time without a mate Disadvantage: DNA does not vary Sexual advantage: makes different combinations of genes Disadvantage: individuals have to find a mate