Exam 36: A: Growth and Development

Stem cells of the early embryo are called totipotent.

The neonatal period lasts from birth until 1 year.

The morula is about three times the size of the zygote.

In most situations,stage II of labor is longer than stages I or III.

One of the early signs of the beginning of labor is the rupture of the amniotic sac.

The infant head is approximately one-fourth the total height of the body.

One possible cause of the degenerative process of aging is the limit on the number of times a human cell can go through mitosis.

The average age-range of adolescence is from 13 to 19 years.

The development of the primary germ layers from the undifferentiated cells of the embryo is called apoptosis.

Experiments have shown that the ovum actually attracts and "traps" sperm with special receptor molecules on the surface of the ovum.

Stage two of labor normally lasts from a few minutes to an hour.

Identical twins are not absolutely identical in terms of structure and function.

By day 35 of development,not only is the heart beating,but the embryo has eyes and limb buds,which will eventually develop into arms and legs.

Stage two of labor is the period from the onset of uterine contractions until expulsion of the placenta through the vagina.

Although there are several thousand primary follicles in the ovary,only one becomes a secondary follicle during each reproductive cycle.

Each primary spermatocyte will produce four functional sperm cells.

When the blastocyst implants too close to the cervix,a condition called abruptio placentae may develop.

The brain and the spinal cord originate in the ectoderm.

If an egg is not fertilized,the first polar body is not formed.

Shortly after birth,all of the systems are fully differentiated; because of that,adults do not have stem cells.