Bio Unit 10b: Who Am I - Genetics

Trait

A characteristic that an organism can pass on to its offspring through its genes.

Gene

A segment of DNA on a chromosome that codes for a specific trait

Allele

one of a number of different forms of a gene

Genotype

An organism's genetic makeup, or allele combinations.

Phenotype

An organism's physical appearance, or visible traits.

Heterozygous

An organism that has two different alleles for a trait

Homozygous

An organism that has two identical alleles for a trait

dominant allele

An allele whose trait always shows up in the organism when the allele is present.

recessive allele

An allele that is hidden whenever the dominant allele is present

monohybrid cross

A cross between two individuals, concentrating on only one definable trait

monogenic traits

Traits determined by a single gene.

polygenic traits

traits controlled by two or more genes

Pedigree

A chart or "family tree" that tracks which members of a family have a particular trait

Carrier

a person who has one dominant allele and one recessive allele for a trait