By the Third Week After Conception, a Sheet of Primitive

question 503

Multiple Choice

By the third week after conception, a sheet of primitive neural cells has formed:

• A) a hollow tube called the neural tube.
• B) a cavity called the ventricle.
• C) a hollow tube called the stem cell.
• D) a cavity called the amniotic sac.

---

Definitions:

Gynecomastia

The benign enlargement of breast tissue in males, which can result from an imbalance of estrogen and testosterone hormones.

Gyncomastia

A disorder characterized by the enlargement of breast tissue in males, often due to hormonal imbalance.

Hypospadias

a birth defect in males in which the opening of the urethra is not located at the tip of the penis.

Epispadias

A rare congenital defect in which the opening of the urethra is on the upper (dorsal) side of the penis, in males, or in an abnormal position in females.