Download Chap. 11 Meiosis Notes Review Key Chap. 11 Meiosis

Chap. 11 Meiosis Notes Review
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Name _________________________
Vocabulary (1 pt ea)
1. gamete: ________egg or sperm__________________________
2. haploid _________only one version of a chromosome – just mom’s or just dad’s________
3. zygote __________a fertilized egg__________________________________________________
4. synapsis ________locating/stacking of homologous chromosomes during Prophase I___
5. synaptonemal complex ___the cohesion proteins that hold the homologous chromosome pairs together during
synapsis_____
6. chiasmata ___the location where non-sister chromatid exchanged genes during genetic recombination_____
7. nondisjunction ___the failure of homologous chromosome pairs to separate during Anaphase I or sister chromatid to
separate during Anaphase II______
8. aneuploid gamete ___an egg or sperm that has too much or too little genetic information due to
nondisjunction______
Discussion:
9. What is the purpose of meiosis? (1 pt) ____production of gametes (egg or sperm)_______________
10. Why does the cell spend the energy to locate and pair homologous chromosomes? (2 pts) ___________________
The chromosomes need to be separated properly (one of each to each new cell) during both anaphase stages.
Pairing them up ensures that the separation goes smoothly.
11. Genetic recombination occurs between non-sister chromatid. Why? (2 pts) _______________________________
___If it occurred between sister chromatid (the original chromosome and it’s duplicate) the same information would be
exchanged._
12. In Metaphase I, chromosomes are randomly lined up along the metaphase plate. What affect does this independent
assortment have on future offspring and what is the evolutionary benefit of independent assortment? (3, 3 pts)
___This allows more variation in the phenotype of the offspring. Offspring can have any combination of genes from both
parents. (Think how siblings look similar but different). ____
___The more genetic variation in the offspring of one generation, the more genetic variation there will be in future
generations. These future generations might have combinations of genes that improve the species, eventually
causing it to evolve.
13. Contrast the processes of mitosis and meiosis.
(Don’t use meiosis happens once and mitosis happens twice)
Mitosis
Cellular repair
No synapsis
No genetic recombination
Diploid daughter cells
2 daughter cells
No reduction division
Meiosis
Production of gametes
Synapsis
Genetic recombination
Haploid daughter cells
4 daughter cells
Reduction division
14. Compare Meiosis I to Meiosis II. (4 pts)
Meiosis I
Synapsis
Genetic recombination
Reduction division
Homologous chromosome pairs are separated
Meiosis II
No synapsis
No genetic recombination
No reduction division
Sister chromatid are separated
15. Identify the phases when nondisjunction can occur. (Hint there are two). (2 pts) __Anaphase I and ___
____Anaphase II___________. What does this mean for the gametes and future offspring? (2 pts)
____The gametes will have too much or too little genetic information. The offspring will have something wrong with
them because of the missing/conflicting information. This could cause birth defects or cause death.___
16. Choose one of the forms of asexual reproduction discussed in the chapter.
- Explain how offspring are produced in this form of reproduction. (1 pt)
- Explain how this form of reproduction is beneficial for the species. (3 pts)
- Explain how this form of reproduction could be detrimental to the species. (3 pts)
_____Budding occurs when the offspring grows from the body of the adult. When it is completely formed, it breaks off
and grows to adulthood.
____Fragmentation occurs when a part of the adult is broken off through injury. The piece grows into an adult.
____Parthenogenesis occurs when there are no males present. The female lays eggs that will hatch into almost
genetically identical offspring.
This form of reproduction is beneficial because it helps to keep the population strong in numbers of individuals. This will
protect the population from dropping too low due to predation, accident, injury etc.
This form of reproduction is detrimental because all of the offspring are almost genetically identical. Any genetic
problems that the mother had are also in the offspring. If a disease should come to the population that the original
female is sensitive to, everyone will get it.