BECOMING HUMAN: Prenatal Development

The third stage of prenatal development is known as the __________ stage and lasts from about two months through birth.

C. fetal

__________ refers to the age between 22 and 26 weeks at which a fetus can survive in the event of a premature birth.

D. Age of viability

What condition results in the mother's body beginning to fight off foreign blood protein produced by the fetus?

D. Rh-factor incompatibility

In which prenatal stage is a fetus' genitalia clearly male or female?

D. fetal stage

Which prenatal stage begins when a zygote is created through fertilization?

D. germinal stage

During weeks 17-20, quickening occurs, which is when the __________.

D. mother is able to feel the fetus move inside her womb

The organ that provides oxygen and nutrition to the fetus and filters out bodily wastes is the __________.

D. placenta

Which of the following does not occur during the embryonic stage?

A. The bones become fully developed.

A(n) __________ is a one-celled organism formed by the union of a sperm and an egg.

A. zygote

__________ introduced during pregnancy may have harmful effects on a fetus.

B. Harmful environmental agents

__________ occurs when the mother's body begins to fight off foreign blood protein produced by the fetus.

B. Rh-factor incompatibility

Neural tube defects are birth defects of the __________ and __________.

B. brain . . . spinal cord

The __________ stage is the third stage of development and lasts from two months through birth.

B. fetal

Severe malnutrition of the mother affects the development of the fetus with all of the following problems except __________.

psychological disorders

Major organs form and cells continue to divide in the __________ stage.

NOT A. zygote

When a mother's immune system reacts to the fetus' blood due to an incompatibility in blood cell type, it is called __________.

Rh incompatibility

A woman's primary concern during her pregnancy should be prenatal care.

T

At the embryonic stage, the zygote becomes the embryo.

T

Harmful environmental agents can sometimes allow fewer nutrients to reach the developing fetus.

T

What is the age of viability, and during what weeks does a fetus reach this age?

The age of viability is the age at which a baby can survive in the event of a premature birth. Most fetuses reach this age between 22 and 26 weeks. Chances of survival are slim at 22 weeks, but they steadily increase over the next few weeks.

Identify and define the three stages of prenatal development.

The three stages of development are the germinal stage, the embryonic stage, and the fetal stage. The germinal stage is the stage from conception to about two weeks. During this stage, a zygote becomes a mass of cells that implants in the uterine wall, marking the start of the placenta's formation. The embryonic stage is the second stage of development and lasts from two weeks until the end of the second month. During this stage, most of the vital organs and various bodily systems begin to develop. The third stage of development is the fetal stage, and it lasts from two months through birth.

All non-harmful environmental agents that a pregnant woman ingests aid in the development of the fetus.

F

The embryonic stage is the first phase of the prenatal stage, lasting only two weeks after conception.

F

Toxoplasmosis is a disease a pregnant woman can contract during the second trimester that can cause congenital varicella syndrome (CVS).

F