Complex inheritance

Complex inheritance and Expression Phenotype can depend on interactions of alleles. Traits can rely on a wide range of dominance. Phenotype can also be influenced by environment Turtle eggs that are held at warmer temperatures tend to turn into female turtles.

Incomplete dominance Incomplete dominance is when the heterozygous is a blending of traits. Example: When a red flower and a white flower have a pink baby.

Incomplete dominance

Codominance Codominance is when both alleles are expressed equally in the heterozygous. Neither allele is dominant or recessive. Example: Example: When a red flower and a white flower have a red and white spotted baby.

Codominance

Polygenic traits A polygenic trait is when many genes interact to produce 1 trait. Human skin color and eye color are examples of polygenic traits. (Look at figure 7.7 on pg. 206).

Epistasis An epistatic gene is one that interferes with the expression of others. For example albinism is caused when an epistatic gene blocks the genes that produce pigment.

Pedigrees A pedigree uses a chart that can trace the phenotypes and genotypes within a family. They are a useful tool in checking a family's history for genetic disorder or disposition.

pedigree The symbols: -Square=male -Circle=female Shaded=have the trait Half-shaded=carriers

Turn and Talk: In what ways can a pedigree be helpful to a family Turn and Talk: In what ways can a pedigree be helpful to a family? Provide evidence for your thinking.

Mapping chromosomes Karyotype is a picture of all of the chromosomes in a cell. They are stained and lined up from largest to smallest with X and Y last.

karyotype

Incomplete Dominance: Explain the phenotype of the offspring from these parents: White rat and Black rat cross Flat Feet and Arched Feet

CoDominance: Explain the phenotype of the offspring from these parents: White Bulldog and Brown Bulldog Type A Blood and Type B Blood

Blood Types