Chapter 4

Question 1

Incomplete dominance and codominance and how to distinguish between the two

Answer 1

incomplete dominance: in between the phenotypes of the two homozygotes (purple, violet, white)

codominance: phenotype of the heterozygote includes the phenotypes of both homozygotes (blood type)

both are a 1:2:1 phenotypic and genotypic ratio in F2

codominant - both are expressed at the same time
incomplete dominance - true mix

Question 2

Lethal alleles and how they affect phenotypic ratio.

Answer 2

alleles can be lethal

taking drugs example.

the ones that are lethal (homozygous), become dead and affect phenotypic ratio.

Question 3

Know what epistasis is, the expected phenotypic ratio, and how to distinguish epistatic and hypostatic genes

Answer 3

epistasis - interaction between genes at different loci so that an allele in one gene (epistatic gene) masks the expression of the phenotype of another gene (labrador example)

recessive epistasis (9:3:4)

Question 4

Understand the basic concepts of sex-linked traits and cytoplasmic inheritance

Answer 4

display different patterns from traits encoded by autosomes

cytoplasmic inheritance - mendel’s laws are based in genes carried on chromosomes in the nucleus
some characters are inherited as genes located in mitochondria or chloroplasts

cytoplasmic genes are passed from the mother only, in the large egg