Inheritance III: Complex Traits

These flashcards are designed to help students review key concepts related to inheritance, complex traits, and genetic principles discussed in the lecture.

What is the expected phenotype ratio from a cross of BbVgVg x bbvgvg if alleles assort independently?

965 gray, normal; 944 black, vestigial; 206 gray, vestigial; 185 black, normal.

According to Mendel’s Law of Independent Assortment, how do alleles assort during gamete formation?

Alleles for different genes sort independently of one another.

If B is dominant for gray body and b is recessive for black body, what will the phenotype be of a Bb fly?

Gray body.

What factors can cause two genes on the same chromosome to assort independently?

Recombination or crossing over during meiosis.

What is pleiotropy?

A condition where one gene affects multiple characteristics.

In the context of X-linked traits, what does hemizygous mean?

An individual with only one allele for a gene, such as males with X-linked traits.

What is the outcome for the male children of a colorblind man and a non-colorblind carrier woman?

There is a 50% chance the sons will be colorblind.

What is polygenic inheritance?

A trait that is controlled by two or more genes.

What phenotype does the black coat color in dogs indicate about their genotype?

They can be either homozygous (BB) or heterozygous (Bb) due to complete dominance.

Explain the concept of epistasis.

When multiple genes interact to influence a single phenotype.

What kind of inheritance pattern is shown by the frizzle feather phenotype in chickens?

Pleiotropy, since frizzle feathers can affect metabolic rates.

How can one determine if genes are linked based on progeny phenotypes?

If the offspring phenotypes deviate from the expected ratios of independent assortment.

What is a possible genotype for a yellow lab if both parents are brown labs?

bbee.

What is a critical feature of quantitative traits?

Phenotypes are continuous rather than discrete categories.

What is the significance of recombination frequency in genetic mapping?

It helps determine the distance between genes on a chromosome.

What does it mean when alleles on separate chromosomes assort independently?

They are inherited without regard to the inheritance of each other.

What evidence suggests that two genes do not assort independently?

Results from crosses that do not fit Mendel’s predicted ratios indicate linkage.