lecture 13: Gene Interactions

What are the basic principles of simple Mendelian genetics regarding alleles and traits?

In simple Mendelian genetics, one gene corresponds to one trait, and for each gene, there are two alleles, one inherited from each parent.

What is the meaning of epistasis in genetics?

Epistasis refers to the interaction between multiple genes where one gene affects or masks the expression of another gene, influencing a single trait.

In simple dominance, how many alleles can there be for a single trait?

There can be two alleles for a single trait in simple dominance.

What happens to traits when you have more than two alleles in a population?

If there are more than two alleles in a population, they can produce multiple traits.

How is lethal alleles related to allelic interactions?

Lethal alleles can be part of allelic interactions where one allele combination can cause death to the organism, impacting the observed phenotypes.

Define recessive epistasis.

Recessive epistasis occurs when the homozygous recessive genotype of one gene masks the effect of another gene, controlling the phenotype.

What phenotypic ratio is commonly associated with recessive epistasis?

The phenotypic ratio commonly observed with recessive epistasis is 9:3:4.

During a dihybrid cross, if the total number of offspring adds up to 16, what does that imply?

It implies that the cross includes two genes and follows a dihybrid inheritance pattern.

What is the primary effect of epistasis in genetic interactions?

The primary effect of epistasis is an inhibitory effect where one gene product inhibits or masks the expression of another gene product, influencing the phenotype.

How do gene interactions generally alter phenotypic outcomes?

Gene interactions alter phenotypic outcomes by affecting how individual genes work together to produce a single trait rather than acting independently.