Genetics

length of claws eye color size are examples of fur color traits

Gregor Mendel ( ) is the father of genetics.

gene for brown hairgene for black hair Traits are controlled by Genes are passed from parent to offspring. genes.

alleles Brown hair Blonde hair Red hair Black hair These are examples of

Each trait is controlled by two alleles, one from each parent. These alleles are located on homologous chromosomes. homologous chromosomes allele for brown hairallele for blonde hair maternalpaternal

Alleles may be dominate or recessive. TRAITSDOMINANTRECESSIVE Flower colorpurplewhite Pea coloryellowgreen Pea shaperoundwrinkled Pod colorgreenyellow Plant heighttallshort

recessive What type of alleles are t, b, r, g What type of alleles are T, B, R, G dominant

An organism is homozygous for a trait. RR rr red white

An organism is heterozygous for a trait. Rr red white

Is the organism homozygous or heterozygous? Aass Bbtt

The set of alleles such as genogenes genotype = genes Tt Bb Ss Hh RR

phph phenotype = physical appearance Curly hair Red flower Long wings Brown eyes freckles

INCOMPLETE DOMINANCE X red white pink ---- has a blending affect.

both alleles are separately expressed. red & white flower X red flower white flower CODOMINANCE

Examples of polygenic traits in humans include: skin color eye color hair color height Polygenic traits are traits produced by two or more genes.

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recessive dominant

homozygous heterozygous

genotypes

Gray fur brown fur phenotypes

Heterozygous Purple X Homozygous White Heterozygous purple P p p p Homozygous white P P pp pp p p

A red flower is crossed with a white flower Red flower R R W W White flower R R W W W W R R Red flower X white flower pink flower The offspring are pink