FLASHCARDS – Lecture 3.1: Monohybrid Cross

Who is the father of genetics?

Gregor Mendel

What type of plants did Mendel study?

Pea plants with traits like flower color and seed shape

What is a monohybrid cross?

A genetic cross that tracks the inheritance of a single gene with two alleles

What is the phenotypic ratio of a monohybrid cross between two heterozygotes?

3 \text{ dominant} : 1 \text{ recessive}

What is the genotypic ratio of a monohybrid cross between two heterozygotes?

1 \text{ homozygous dominant} : 2 \text{ heterozygous} : 1 \text{ homozygous recessive}

What is the difference between genotype and phenotype?

Genotype is the genetic makeup (e.g., Pp), phenotype is the observable trait (e.g., purple flowers)

What does it mean to "breed true"?

Offspring always have the same phenotype; the parent is homozygous

If a purple flower plant (Pp) is selfed, what proportion of its purple offspring are homozygous (PP)?

1/3 of the purple plants

What is a testcross?

A cross between an individual with a dominant phenotype and a homozygous recessive to determine the unknown genotype

In a testcross, what does 100\% dominant offspring indicate?

The tested parent is homozygous dominant, producing 100\% dominant offspring.

In a testcross, what does a 1:1 phenotypic ratio indicate?

The tested parent is heterozygous, producing a 1:1 phenotypic ratio.