Exercise 43
CHAPTER 43
1)
1. C 7. B 2. B 8. A 3. A 9. B 4. B 10. C 5. C 11. B 6. A 12. B
2) Describe the process of synapsis
The pairing of homologous chromosomes (23 tetrads become attached to spindle fibers & begin to align on the equator.
3) How does crossover introduce variability in the daughter cells?
The homologues separate from one another, breaking & exchanging parts- where crossovers occur
4) Define homologous chromosomes
Egg & sperm chromosomes that carry genes for the same traits (1 paternal, 1 maternal)
5)
1. Primitive stem spermatogonium
2. Haploid secondary spermatocyte, spermatid, sperm
3. Provides nutrients to developing sperm sustentacular cells
4. Products of meiosis II spermatid
5. Product of spermiogenesis sperm
6. Product of meiosis I spermatocyte
6) Why are spermatids not considered functional gametes?
They are non-motile and have too much excess baggage to function well in a reproductive capacity.
7) Differentiate between spermatogenesis and spermiogenesis
Spermiogenesis is the final stage of spermatogenesis, which sees the maturation of spermatids into mature, mobile spermatozoa. * Formation of haploid gametes by male sloughing off excess spermatid cytoplasm to form a functioning sperm
8) Draw a sperm, label: acrosome, head, mid piece and tail. Beside each label, note the composition, and function of each sperm structures. Acrosome :( composition & function) penetrating device containing digestive enzymes Head :( composition & function) genetic region, nucleus
Mid piece :( composition & function) contains mitochondria which provide ATP
Tail :( composition & function) contractile filaments (loco motor region)
9) The lifespan of a sperm is very short? What anatomical characteristics might lead you to suspect this even if you don't know its life span?
No cytoplasm in which to store nutrients
10) The sequence of events leading to germ cell formation in the female begins during fetal
1)
1. C 7. B 2. B 8. A 3. A 9. B 4. B 10. C 5. C 11. B 6. A 12. B
2) Describe the process of synapsis
The pairing of homologous chromosomes (23 tetrads become attached to spindle fibers & begin to align on the equator.
3) How does crossover introduce variability in the daughter cells?
The homologues separate from one another, breaking & exchanging parts- where crossovers occur
4) Define homologous chromosomes
Egg & sperm chromosomes that carry genes for the same traits (1 paternal, 1 maternal)
5)
1. Primitive stem spermatogonium
2. Haploid secondary spermatocyte, spermatid, sperm
3. Provides nutrients to developing sperm sustentacular cells
4. Products of meiosis II spermatid
5. Product of spermiogenesis sperm
6. Product of meiosis I spermatocyte
6) Why are spermatids not considered functional gametes?
They are non-motile and have too much excess baggage to function well in a reproductive capacity.
7) Differentiate between spermatogenesis and spermiogenesis
Spermiogenesis is the final stage of spermatogenesis, which sees the maturation of spermatids into mature, mobile spermatozoa. * Formation of haploid gametes by male sloughing off excess spermatid cytoplasm to form a functioning sperm
8) Draw a sperm, label: acrosome, head, mid piece and tail. Beside each label, note the composition, and function of each sperm structures. Acrosome :( composition & function) penetrating device containing digestive enzymes Head :( composition & function) genetic region, nucleus
Mid piece :( composition & function) contains mitochondria which provide ATP
Tail :( composition & function) contractile filaments (loco motor region)
9) The lifespan of a sperm is very short? What anatomical characteristics might lead you to suspect this even if you don't know its life span?
No cytoplasm in which to store nutrients
10) The sequence of events leading to germ cell formation in the female begins during fetal