CHAPTER 3 - LESSON 4 - PREGNANCY AND CHILDBIRTH REVIEW

The reproductive system enables ...

• living beings to produce offspring. The reproductive system in males and females produces cells for reproduction.
• the sum of traits that have been transmitted from a person's biological parents.
• 22 chromosomes plus an X or a Y chromosome.
• observable trait only if the other gene in the pair is the same.

Males produce ...

• egg cells.
• sperm cells.

Females produce ...

• egg cells.
• sperm cells.

Each person begins as ...

• a fetus (FEE-tuhs).
• a single cell produced by fertilization.

Fertilization (fuhr-tuh-luh-ZAY-shun) is the ...

• joining of a sperm cell and an egg cell to make a single cell called a fertilized egg. The fertilized egg divides and attaches itself to the uterus.
• the sum of traits that have been transmitted from a person's biological parents.
• a muscular organ in a woman's body that supports the development of the fertilized egg during pregnancy.

The uterus (YOOtuh-rus) is ...

• a muscular organ in a woman's body that supports the development of the fertilized egg during pregnancy.
• the sum of traits that have been transmitted from a person's biological parents.
• strands of matter found in the nucleus of a cell. Most human cells contain 46 chromosomes, but reproductive cells contain only half as many.

Heredity is ...

• the time between fertilization and birth, about nine months.
• an observable trait.
• the sum of traits that have been transmitted from a person's biological parents.

You inherit traits through chromosomes (KROH»muh»sohmz), ...

• 22 chromosomes plus an X chromosome.
• strands of matter found in the nucleus of a cell. Most human cells contain 46 chromosomes, but reproductive cells contain only half as many.
• 22 chromosomes plus an X or a Y chromosome.

An egg cell has ...

• 22 chromosomes plus an X or a Y chromosome.
• 22 chromosomes plus an X chromosome.

A sperm cell has ...

• 22 chromosomes plus an X or a Y chromosome.
• 22 chromosomes plus an X chromosome.