11.4 Sexual Reproduction (IB Biology)

The diagram shows a section through the seminiferous tubules. What is the cell labelled X?

• Spermatid that will differentiate into sperm

• Primary spermatocyte that will undergo meiosis to form secondary spermatocytes

• Sertoli cell that provides nutrients

• Stem cell that will divide by mitosis to form spermatogonia

The image shows a light micrograph of tissue stained with a dye that binds to the nucleic acids in a cell. What is the major purpose of the tissue depicted in the image?

• Absorption of digested food

• Production of insulin

• Spermatogenesis

• Fertilization

The image shows a flow chart. Which sequence would correspond to the stages shown in the flow chart?

• sexual intercourse--ovulation--pregnancy--maintenance of endometrium

• disintegration of corpus luteum--pituitary gland activity-estrogen production-- ovulation

• mitosis--growth--differentiation--pregnancy

• implanted embryo--corpus luteum of ovary--progesterone production--maintenance of endometrium

If the ovaries of a pregnant woman have to be removed during the first five months of pregnancy, a miscarriage results and the pregnancy fails. If the ovaries are removed in the last four months of pregnancy, the miscarriage does not occur. What is the reason for this?

• After the fifth month, the ovaries can regenerate rapidly.

• The placenta produces sufficient hormones to sustain the pregnancy.

• The pituitary gland takes over the function of sustaining the pregnancy.

• Before removal the ovaries produce sufficient hormones to sustain the pregnancy.

Which interaction occurs between hormones in the reproductive systems of women?

• Estrogen from the corpus luteum stimulates secretion of FSH.

• Estrogen from the follicle stimulates secretion of LH at midcycle.

• Progesterone stimulates secretion of LH after ovulation.

• During birth, progesterone stimulates secretion of oxytocin.

The diagram shows the female reproductive system. Which structures do K and L identify?

• K: endometrium L: uterine wall

• K: placenta L: endometrium

• K: amnion L: placenta

• K: fetus L: uterine wall

Which hormone is inhibited during pregnancy in order to prevent contractions of the uterus?

• Oxytocin

• Progesterone

• Estrogen

• FSH

The diagram shows the exchange processes that take place in the placenta between the maternal and fetal blood. Which process requires endocytosis?

• A

• B

• C

• D

What does the blastocyst secrete?

• HCG

• Estrogen

• ADH

• Progesterone

What helps to prevent polyspermy?

• The unequal division of oocytes

• The placental barrier

• The contraceptive pill

• The cortical reaction