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:
1. last trimester
2. third to sixth month
3. first trimester
4. a week prior to parturition

Implantation does not:
1. involve a blastocyst
2. occur in the uterine tube
3. establishes pregnancy
4. occurs by seventh-eighth day

Seminal plasma has contributions of all the following except:
1. bulbourethral glands.
2. testes.
3. seminal vesicles.
4. prostate gland

Type B spermatogonia divide to form: