Self Quiz 46/47

Diploidy is first reestablished following

fertilization

An advantage of internal fertilization over external fertilization is that

internal fertilization prevents the drying out of gametes in a dry environment.

In humans, the ___ of the sperm enter(s) the oocyte

nucleus

In humans, oogenesis is completed

once the sperm penetrates the oocyte.

Spermatogenesis and oogenesis differ in that

oogenesis produces one egg and spermatogenesis produces four sperm.

Cleavage of the zygote begins in the

oviduct

An infant suckling on the breast of a woman who has recently given birth sends a nerve impulse to the pituitary gland. The pituitary gland then secretes oxytocin, which stimulates the mammary glands in the breasts to release milk. What type of hormonal feedback is this?

positive feedback

A blood sample taken from a woman in her 40s showing high levels of estrogen, progesterone, hCG, and prolactin suggests that

she is pregnant.

The formation of the fertilization membrane and the slow block to polyspermy are dependent on

the entrance of calcium ions into the egg.