B. Answer the following questions in detail :
1. Differentiate between internal and external fertilization.
2. How does fertilization occur?
3. How is the sex of a child determined?
4. How does external fertilization occur?
5. What are important functions of endocrine glands?
6. What are hormones? List some hormones and their functions.
Answers
Explanation:
(1) Internal fertilizationis the process when the syngamy (union of male and female gamete) occurs inside the female body after insemination using copulation. In contrast, External fertilization is thesyngamy outside the female body, that is in the outer environment especially in water bodies.
(2)A pregnancy starts with fertilization, when a woman's egg joins with a man's sperm. Fertilization usually takes place in a fallopian tube that links an ovary to the uterus. If the fertilized egg successfully travels down the fallopian tube and implants in the uterus, an embryo starts growing.
(3)Men determine the sex of a babydepending on whether their sperm is carrying an X or Y chromosome. An X chromosome combines with the mother's X chromosome to make ababy girl (XX) and a Y chromosome will combine with the mother's to make a boy (XY).
(4)Most external fertilization happensduring the process of spawning where one or several females release their eggs and the male(s) release sperm in the same area, at the same time. The release of the reproductive material may be triggered by water temperature or the length of daylight.
(5)Endocrine glands release hormones into the bloodstream. This lets the hormones travel to cells in other parts of the body. The endocrine hormones help control mood, growth and development, the way our organs work,metabolism , and reproduction. The endocrine system regulates how much of each hormone is released.
Answer: