Sexual reproduction in humans：练习题

In the human female reproductive system, what is the specific site where fertilisation typically occurs?

The diagram shows the exchange of materials between a mother and her fetus. Which of the following correctly identifies substances that move by diffusion from the fetal blood to the maternal blood across the placenta?

Which hormonal change is the most direct trigger for ovulation during the human menstrual cycle?

Which part of a sperm cell contains enzymes that are used to penetrate the jelly coat of an egg cell?

Human sperm cells possess a large number of mitochondria within the middle piece of the cell. What is the specific functional advantage of this adaptation?

Identify two useful substances that are transferred from the blood of the mother to the blood of the fetus through the placenta.

State the specific roles of testosterone and oestrogen in the development and regulation of secondary sexual characteristics during human puberty.

Describe the function of the amniotic sac and the amniotic fluid during human fetal development, and explain how these structures provide mechanical protection.

In the human menstrual cycle, several hormones coordinate the changes in the ovaries and the uterus.
(a) Name the two hormones secreted by the pituitary gland that control the menstrual cycle.
(b) Explain how these two hormones interact to trigger ovulation.

During the development of a human fetus, various structures provide protection and nourishment.
(a) State two functions of the amniotic fluid surrounding the fetus.
(b) Explain the role of the umbilical cord in the exchange of materials between the mother and the fetus.
(c) Although the placenta acts as a barrier, explain why pregnant women are advised to avoid nicotine and alcohol.