Exam 36: A: Growth and Development

The "barrel chest" in some elderly adults results from the calcification of the costal cartilages.

The placenta,a structural "anchor" and nutritive bridge,is also an excretory,respiratory,and endocrine organ.

Degenerative heart and blood vessel disease is one of the most common and serious effects of aging.

Identical twins are always of the same sex.

Once the zygote is formed,it immediately begins to cleave,and in about 3 days a solid mass of cells called a blastocyst is formed.

Atherosclerosis results when fatty accumulations or other substances in blood vessels calcify.

In both oogenesis and spermatogenesis,the cytoplasm is equally divided among the daughter cells.

Both peristaltic contractions and cilia assist the sperm in moving through the uterine tubes.

Cells of the embryonic disk differentiate into distinct types that form each of the three primary germ layers.

In older adulthood,the bones develop indistinct and shaggy-appearing margins with spurs,a process called lipping.

When a sperm enters the egg,the sperm causes an increase in potassium ions in the ovum,which inactivates the sperm receptors in the zona pellucida.

The blastocyst is a solid mass of cells.

The developing baby is referred to as a zygote during the first trimester,an embryo during the second trimester,and a fetus during the third trimester.

Alcohol can cross the placental barrier and cause injury to the developing fetus.

One theory of aging proposes that a lack of ATP in the cell causes aging.

Fraternal twins are always of two different sexes.

The function of polar bodies is to reduce the number of chromosomes in the developing ova.

The end products of both spermatogenesis and oogenesis are gametes.

Human cells contain a total of 23 chromosomes.

Enzymes in the acrosome of the sperm are used to break down the zona pellucida of the egg.