Question

1. How is reproduction different in birds and humans?
2. Do you think genetics have anything to do with producing eggs you buy in the store?
3. Why don’t birds generally reproduce during winter?
4. If birds do not reproduce during winter, why are eggs always available in the grocery store?
5. Why are light and heat useful environmental factors for controlling reproduction?
6. Describe the hormones that control reproduction in males and females.
7. Why did it take some time for reproduction to be triggered?
8. What different characteristics and behaviors were changed in the quail?
9. Why is it necessary to have genes under various controls in a cell?
10. Would any negative effects result from artificially creating a year-round breeding environment for quail or chickens?

Answer 1

4In humans men have XY chromosome and women two X chromosome but the Birds hv evolved similar system with a twist its the male that have two of the same chromosome. Their Chromosome are called Z and W which are derived from different pair of ancestral chromosomes then X and Y.The Z evolution hs in several ways paralleled that of X EVEN THOUGH EACH IS ASSOCIATED WITH A DIFFERENT SEX..In BIRDS X chromosome too has added sperm related genes which flies in face of common wisdom about the X THAT IT MUST BE A FEMALE BIASED CHROMOSOME.In humans default condition is female and reproductive organs develop as male in presence of male determining gene protein.Birds embryo expose to a single dose develop as female;two copies of gene make a male.

Birds will freeze to death when temperature drops and they therefore store fat during short days of winters to keep themselves warm during long winter nights.During those winter they fluff their weathers to trap heat and slow their metabolism to conserve energy so they cannot reproduce during this time.

Artificial light control reproductive tract development of birds during puberty and heat enhances reproduction .

The Leydig cells produce testosterone which is responsible for secondary sexual characters of male and FSH and LH cause ESTROGEN and PROGESTERONE to be produced.They regulate female ovarian and menstrual cycle

Artificial lighting stimulate egg production during winters so eggs are always available in grocery stores.