Reproduction, growth and development：練習問題

Which organ in the human female reproductive system is primarily responsible for providing a suitable environment for the implantation and development of an embryo?

During the human menstrual cycle, after ovulation, which hormone is primarily responsible for maintaining the thickened uterine lining, preparing it for possible implantation?

In the human female reproductive cycle, the maintenance of the corpus luteum is crucial for sustaining the uterine lining after ovulation. In a cycle where fertilization does not occur, the corpus luteum degenerates, leading to menstruation. However, if implantation of a fertilized egg occurs, the corpus luteum persists for several months. Which of the following accurately describes the mechanism responsible for preventing the degeneration of the corpus luteum during early pregnancy?

Which gland in the human male reproductive system produces a fluid rich in fructose to provide energy for sperm motility?

Which of the following adaptive features is most characteristic of an insect-pollinated flower?

State three essential environmental conditions required for the germination of seeds.

Explain why the presence of amniotic fluid in the amniotic sac is essential for the physical protection of a developing human foetus during pregnancy.

State the biological principle of a vasectomy as a permanent method of birth control in the human male.

(a) Distinguish between the formation of identical twins and fraternal twins in terms of the number of gametes involved and the genetic composition of the offspring.
(b) The placenta is a vital organ for the survival of the foetus. Describe three structural adaptations of the placenta that facilitate the efficient exchange of materials such as oxygen \( (O_2) \) and glucose \( (C_6H_{12}O_6) \).
(c) Explain how the placenta functions as a barrier, and identify two types of substances or agents that can bypass this barrier to negatively affect the foetus.