GENETICS

Gregory MENDELWHO?

Father of Genetics = Pea Plants

Independent Assortment

Genes that segregate independently, do NOT influence each other’s inheritance.

Separate genes for separate traits are passed independently of one another from parents to offspring

Dominant vs. Recessive

Traits

Dominant Recessive

Dominant Recessive

Dominant Recessive

Dominant Recessive

Dominant Recessive

Dominant Recessive

Dominant Recessive

Dominant Recessive

Some alleles are neither dominant nor recessive, and many traits are controlled by multiple alleles or

multiples genes.

Incomplete Dominance

Where one allele is not completely dominant over another.

Heterozygous phenotype is somewhere in between the two homozygous phenotypes.

Codominance

Both alleles contribute to the phenotype (physical characteristics).

Both alleles are FULLY EXPRESSED.

Multiple Alleles

Genes that have more than 2 alleles.

More than 2 possible alleles exist in the population.

Polygenic Traits

Traits controlled by two or more genes.

Traits that are produced by the interaction of several genes.

The FOIL method is ONLY used when finding the gametes from parents with

two traits. Use the FOIL method to find the

gametes:(RrYy)

(R + r)(Y + y). F tells you to put the FIRST of the two

traits’ alleles together.

RY

(R + r)(Y + y). O tells you to put the OUTER alleles

together.

Ry

(R + r)(Y + y). I tells you to put the INNER alleles

together.

rY

(R + r)(Y + y). L tells you to put the LAST alleles

together.

ry

Remember, FOIL reminds you to match up the:

First alleles

Outer alleles

Inner alleles

Last alleles