W12 L1 - Mendelian Genetics and Evolution - Lecture 7

Flashcards covering key concepts from lecture 7, including Mendelian genetics, independent assortment, epistasis, polygenic inheritance, genetic linkage, and recombination.

What happens in a monohybrid Punnett square?

One gene segregates; since there is one gene, it has two alleles, there are two columns and two rows in that Punnett square.

What happens in a dihybrid Punnett square?

Two genes segregate, and since there are two genes, there are two alleles for each gene, there are four columns and four rows.

What are epistatic interactions between genes?

This is where you have two genes that are working together to control the trait, and they're working in some kind of master control and subsidiary control locus.

Define polygenic inheritance

Where you have many genes controlling your trait and the phenotype is determined not by one gene, but by the interaction of multiple genes.

What is a complementation test?

A test to determine if two animals with the same recessive phenotype have mutations in the same gene or in different genes.

Define pleiotropy.

When one gene controls several different traits.

What is the general rule for creating a pedigree?

A square is a male, and a circle is a female

Define genetic linkage.

The causative allele for male patella syndrome is on the same chromosome as the gene for ABO blood group and it is close to that gene, which means they get inherited together most of the time

What is crossing over and recombination?

During meiosis, homologous chromosomes line up next to each other and undergo recombinational exchange.

What does genetic distance indicate?

The likelihood of crossing over between two genes indicates how far apart they are on the chromosome.

Describe parental types.

The combinations of alleles that an individual inherited from their parents.

Describe recombinant types.

New combinations of alleles that result from crossing over during meiosis.

What is a two-point test cross?

A method to measure linkage between two genes by crossing a doubly heterozygous parent with a fully recessive parent.

What is the definition of centimorgans?

A unit of measurement for genetic distance, where one centimorgan equals 1% recombination frequency.