Mitosis and Meiosis and the Cell Cycle Glossary

alleles

One of the different forms of a gene that can exist at a single locus. A single allele for each locus is inherited separately from each parent.

centromere

The region of the chromosome associated with the attachment of the chromatids to the spindle fibers.

chromatid

One of the two side-by-side replicas of a chromosome produced through DNA replication during mitosis/meiosis.

chromosome

A genetic structure in a cell composed of condensed DNA, which contains the genetic code for an organism.

chromosomes

The genetic structures in cells composed of condensed DNA ,which contain the genetic code for an organism.

cytoplasm

A compartment in a plant or animal cell surrounding the nucleus in which many cell organelles and molecules are suspended.

frequency

A measure of the number of times per second (units of sec-1) that the electric field in a photon vibrates.

gamete

A mature male or female reproductive cell (sperm or ovum) containing half of the total number of chromosomes in a cell (i.e., humans have 46 chromosomes per cell; gametes would have 23).

gametes

Mature male or female reproductive cells (sperm or ovum) containing half of the total number of chromosomes in a cell (i.e., humans have 46 chromosomes per cell; gametes would have 23).

genes

The fundamental unit of heredity that carries genetic information from one generation to the next. A gene is an ordered sequence of nucleotides located on a particular position on a particular chromosome that encodes a specific functional protein.

genotype

The allelic composition of a cell or organism.

germline cells

Cells that give rise to gametes, the reproductive cells of an organism, (such as an egg or sperm), that have only one set of chromosomes. When the two unite, they form a living embryo.

heterozygous

An organism that has two different alleles at one or more locations on a chromosome.

interphase

The stage of cell division when DNA is replicated; a copy of each chromosome is made.

meiosis

A type of cell division which results in the formation of gametes, cells with half the normal number of chromosomes.

nucleus

The part of the plant or animal cell that contains the chromosomes.

replicate

The copying of a DNA molecule in a cell.

replicated

Copied DNA. To make copies of DNA.

replication

The copying of a DNA molecule.

somatic

Body cells.

zygote

The cell formed when the egg and sperm fuse. The cell has two copies of each chromosome (2n) and will continually divide to develop into an entire organism.