Question

. Describe the hormonal changes that occur as a result of implantation, including production of human chorionic gonadotropin (HCG) to maintain the corpus luteum and increased production of progesterone by the corpus luteum

Part C: Read these passages from the text and answer the questions that follow. The only obvious difference between boys and girls at birth is their reproductive organs. However, even the reproductive organs start out the same in both sexes. In the first several weeks after fertilization, males and females are essentially the same except for their chromosomes. Females have two X chromosomes (XX), and males have an X and a Y chromosome (XY). Then, during the second month after fertilization, genes on the Y chromosome of males cause the secretion of testosterone. Testosterone stimulates the reproductive organs to develop into male organs. (Without testosterone, the reproductive organs always develop into female organs.) Although boys have male reproductive organs at birth, the organs are immature and not yet able to produce sperm or secrete testosterone. The reproductive organs grow very slowly during childhood and do not mature until puberty. Puberty is the period during which humans become sexually mature. In the U.S., boys generally begin puberty at about age 12 and complete it at about age 18. What causes puberty to begin? The hypothalamus in the brain “tells” the pituitary gland to secrete hormones that target the testes. The main pituitary hormone involved is luteinizing hormone (LH). It stimulates the testes to secrete testosterone. Testosterone, in turn, promotes protein synthesis and growth. It brings about most of the physical changes of puberty.

1) What is the difference between the male and female chromosomes?

2)Describe the role of testosterone during development.

3)3. Define “puberty.” When does puberty begin in boys?

4. What causes puberty to begin?

5. What is luteinizing hormone? What does it do?

Answer 1

1. The main difference is male and female chromosomes are X and y chromosomes

Female has two x chromosomes where as male has one X and one Y chromosome.

2 during the second month after fertilization gene of Y chromosomes secretes the  testosterone. It is used to develop the male reproductive organs. Without testosterone the it develop female reproductive organs.

3. Puberty means it is period which humans become sexually mature. In the US boys are generally start puberty at the age of 12 and complete at 18.

4 the hypothalamus in the brain tells to the pitutary gland to secrete the hormones that target the testes.

5

4.