HEREDITY Passing traits from parent to

offspring.

Traits Physical characteristics inherited by the

offspring from the parents. Ex. Hair color Eye color Skin tone Ear shape

Traits are Controlled by Genes Genes are located on your chromosomes Individuals inherit genes from your

parent. Your cells contain 23 chromosome pairs

Your are literally half your mother and father.

You receive half the pair from you mother.

You receive half the pair from your father .

Though the gene may be present on both, the form of the gene may be different

Different forms of the same gene are called alleles.

Human Chromosomes

Genetics The study of how traits are

inherited through the inactions of alleles.

Alleles interact to produce traits

Phenotype describes the physical characteristic that is displayed by your genes

Ex. Blue eyes

Genotype describes the actual genes that you have on your DNA

Ex. (blue allele)+(blue allele)

Dominant Alleles When paired a dominate allele will cover up

the phenotype of a recessive allele. Dominate alleles are described with a capital

letter Ex. brown eyes (B) or blue (e) produces “Be” a

brown eye. “BB” will also produce a brown eye.

Recessive Alleles The phenotype for recessive alleles will only

appear if two recessive alleles are paired. Recessive alleles are described with a lower

case letter Ex. A blue eye allele (e) and a blue eye allele

(e) produces “ee” blue eyes

Heterozygous This means “not pure or different.”

Allele pairs are heterozygous if the gene pairs are dominate/recessive pairs.

Ex. Ee, Bd, Aa, Ts

This means “pure or the same.” Allele pairs are homozygous if both alleles are either both dominate or both recessive.

Ex. EE, TT, aa, bb, CC, ff

Homozygous