The Reproductive System

Skin

An organ made of skin cells that helps protect the body.

Cell Theory

States that all living things are made up of cells and that the cell is the basic unit of life.

Neurons

Brain cells that transmit signals throughout the nervous system.

Cardiac Muscle Cells

A type of muscle cell in the heart specialized for pumping blood.

Chromosomes in Human Cells

Most human cells have 46 chromosomes (23 pairs), except for gametes, which have 23 chromosomes (1 from each pair).

Gametes

Sex cells; male gametes are called sperm and female gametes are called eggs.

Somatic Cells

Body cells that make up all tissues and organs in the body, except for gametes.

Diploid

A term describing somatic cells that contain two sets of chromosomes (one from each parent).

Sexual Reproduction

The process by which two parent organisms combine their genetic material to produce offspring with genetic variation.

Egg

The female gamete produced in the ovaries.

Sperm

The male gamete produced in the testes.

Fertilization

The union of the male gamete (sperm) and the female gamete (egg), resulting in the formation of a zygote.

Zygote

A fertilized egg that results from the fusion of sperm and egg; it is the first cell of a new organism.

Haploid cell

cells that have one set of chromosomes (23 in humans)

Diploid cells

cells that have two sets of chromosomes (46 in humans).