Bio chapter 8

Codominance

involves the expression of both alleles at a locus producing two different phenotypes.

Mother: IAIO; father: IBIO

A woman of blood group A has a child with a man of blood group B. The child's blood is type O. What are the genotypes of the parents?

epistasis.

Coat color in rabbits involves the effects of multiple gene interactions. If a rabbit has two recessive alleles (cc) for coat color, it is always albino no matter what the genotype of other genes involved in coat color. This is an example of:

from the mother.

Genes located on mitochondrial DNA are usually inherited

Heterozygous: Rr

In a test cross, peas of an unknown genotype are crossed with peas of a known genotype. In this example, smooth peas are the unknown and wrinkled peas are the known (rr). If half of the offspring from that cross are smooth and half are wrinkled, what is the genotype of the unknown plant?

sex chromosome; autosomes

In many animals, including humans, sex is determined by a single _______, or by a pair of them. Both males and females have two copies of each of the rest of the chromosomes, which are called _______.

male offspring who receive the mutant X chromosome would show the trait.

In sex-linked inheritance of a recessive gene, if a normal male and a heterozygous female carrier mated, all:

many combinations of genes and parts of genes that originated from both the organism's male or female parent.

Independent assortment results in gametes containing

can result in bacterial strains resistant to antibiotics.

Lateral gene transfer between individuals of a species

1⁄4

Suppose unattached earlobes are a dominant trait. Phil and Maggie both have unattached earlobes but their daughter, Celia, does not. If Phil and Maggie have a second child, what is the probability that he or she will have attached earlobes?

through a dihybrid cross in which the genes are on different chromosomes.

The 9:3:3:1 ratio is obtained

dihybrid; independent assortment

The cross AaBb × AaBb is an example of a _______ cross; the results of such crosses led Mendel to propose what we now call the law of _______.

multiple alleles and the environmental influences on the expression of these genes.

The fact that a trait such as height in humans varies over a wide range of values is due to:

1⁄4

What fraction of offspring of the cross Aa × Aa is homozygous for the dominant allele?

9⁄16

What fraction of the offspring of the cross AaBb × AaBb would show the dominant phenotypes for both genes?

incomplete dominance.

When a true-breeding red flower is crossed with a white flower, and all the F1 flowers are pink, this is due to:

Sex-linked on X chromosome

Wild-type fruit flies have red eyes. A white-eyed female fly is crossed with a red-eyed male fly. All of the females from the cross are red-eyed and all of the males are white-eyed. What type of inheritance pattern is this?

Heterosis

_______ is the term for when heterozygous offspring have superior fitness than their homozygous parents.

Incomplete dominance

results in a phenotypic ratio of 1:2:1 in the F2 generation from a monohybrid cross