Exam 36: A: Growth and Development

Sperm are attracted to the warmer temperatures of the uterine tubes; this attraction is called thermotaxis.

The chorion develops from the trophoblast to become an important fetal membrane in the placenta.

Adult stem cells are called pluripotent.

Several thousand primary oocytes formed in the fetus do not survive to puberty.

In mitosis,DNA replicates once.In meiosis,DNA replicates twice.

A woman is fertile for only about 24 hours during each reproductive cycle.

Over the next 40 years,the fastest growing age group will be people between the ages of 45 and 65.

It is possible for fraternal twins to have two different biological fathers.

A tubal pregnancy is an example of an ectopic pregnancy.

The placenta is composed of both maternal and embryonic tissue.

The postnatal period begins at birth and ends when sexual maturity is attained.

By the end of the first trimester,the sex of the baby can be identified.

During meiosis II,the phenomenon of "crossing over" occurs.

Childhood lasts from the end of infancy to puberty,which is from 10 to 12 years of age in girls and 12 to 14 years of age in boys.

With aging,the skin thickens,causing wrinkles.

The ultimate purpose of the human chorionic gonadotropin is to maintain the lining of the uterus.

Both spermatogenesis and oogenesis rely on polar bodies to reduce the chromosome number.

By the second month of gestation,all organ systems of the embryo are formed and functioning.

By day 35 of gestation,the heart of the embryo is beating.

Identical twins share an umbilical cord and a placenta.