Trait- a distinguishing quality that all members of a species have in common.

Varaitions-different forms of the same trait.

Heredity- The passing of of traits from parents to offspring.

Gene-A small segment of DNA that carries Hereditary information.

Alleles- Different forms of a single gene.

Genotype- the combination of an organisms genetic makeup.

Phenotype- The observable traits of an organism.

Nucleotide- The combination of nitrogen base, sugar, and phosphate that form a subunit of the DNA chain.

Mutation- A change in the sequence of one or more nucleotides in a DNA molecule.

Karyotype- the arrangment of chromosome pairs by shape, size, and chromosome number.

Biosphere- The part of earth and its atmosphere in which living organisms exist.

Ecosystem- a system in which organisms and their enviornment interact.

community- all of the living things in a ecosystem.

Habitat- The place in which an organism lives-the place where all of its needs are met.

Food chain-The food and energy links in a community.

food web- The network of food chains in an ecosystem.