The middle piece of a sperm contains __________.
1. food necessary to nourish the head of the sperm
2. enzymes necessary to penetrate the egg's outer layers
3. mitochondria to provide energy for movement
4. all of the above

The anterior pituitary secretes gonadotropins:
1. only in females
2. only in males
3. in both males and females
4. only in males, and females after menopause

The location of ovaries in the human body would most accurately be described as:

Epithelial linings of the digestive tract is derived from the embryonic:
1. ectoderm
2. mesoderm
3. endoderm
4. allantois

Oxygen rich blood and nutrients are transported to the fetus by:

Within the fetus, much of the circulating blood bypasses the lungs and flows through the ______________.
1. ductus venosus
2. umbilical vein
3. umbilical artery
4. ductus arteriosus

The developing embryo gets implanted on the wall of uterine endometrium at the stage of:
1. gastrula
2. blastocyst
3. morula
4. zygote

Erythropoiesis in the earliest days of gestation is the function of:

A second pregnancy during an ongoing pregnancy is prevented by:

The most critical period of gestation where the fetus is most vulnerable to genetic birth defects from drugs taken by the mother is: