Heredity - Key terms



ALLELE:

For any locus, one of two (or more) slightly different forms of a gene. These differing forms mean that alleles code for different versions of the same trait.

AUTOSOMES:

The 22 non-sex chromosomes.

CHROMOSOME:

A DNA-containing body, located in the cells of most living things, that holds most of the organism's genes.

DNA:

Deoxyribonucleic acid, a molecule in all cells, and many viruses, that contains genetic codes for inheritance.

DOMINANT:

In genetics, a term for a trait that can manifest in the offspring when inherited from only one parent. Its opposite is recessive.

GENE:

A unit of information about a particular heritable trait. Usually stored on chromosomes, genes contain specifications for the structure of a particular polypeptide or protein.

GENE POOL:

The sum of all the genesshared by a population, such as that of aspecies.

GENETIC DISORDER:

A condition, such as a hereditary disease, that can be traced to an individual's genetic makeup.

GENETIC DOMINANCE:

The ability of a single allele to control phenotype.

GENOTYPE:

The sum of all genetic input to a particular individual or group.

GERM CELL:

One of two basic types of cells in a multicellular organism. In contrast to somatic, or body, cells, germ cells are involved in reproduction.

HEREDITY:

The transmission of genetic characteristics from ancestor to descendant through the genes.

HETEROZYGOUS:

Having two different alleles—for example, Bb.

HOMOZYGOUS:

Having two identicalalleles, such as BB or bb.

LOCUS:

The position of a particular gene on a specific chromosome.

MUTATION:

Alteration in the physical structure of an organism's DNA, resulting in a genetic change that can be inherited.

NUCLEUS:

The control center of a cell, where DNA is stored.

PHENOTYPE:

The actual observable properties of an organism, as opposed to its genotype.

RECESSIVE:

In genetics, a term for a trait that can manifest in the offspring only if it is inherited from both parents. Its opposite is dominant.

SEX CHROMOSOMES:

Chromosomes that determine gender. Human females have two X chromosomes (XX), and males have an X and a Y (XY).

SYNTHESIZE:

To manufacture chemically, as in the body.

Also read article about Heredity from Wikipedia

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