Genotype and Phenotype Concepts

Front

What is a genotype?

Back

The genetic makeup of an organism, represented by the alleles it possesses (e.g., AA, Aa, aa).

Front

What is a phenotype?

Back

The observable physical or biochemical characteristics of an organism, determined by its genotype and environment.

Front

What is the phenotypic ratio of a monohybrid cross between two heterozygous parents (Aa x Aa)?

Back

3:1

Front

What is the difference between homozygous and heterozygous?

Back

Homozygous has identical alleles (e.g., AA or aa), while heterozygous has different alleles (e.g., Aa).

Front

What does it mean if an organism is homozygous dominant?

Back

It has two identical dominant alleles for a trait (e.g., AA).

Front

What does it mean if an organism is homozygous recessive?

Back

It has two identical recessive alleles for a trait (e.g., aa).

Front

What does it mean if an organism is heterozygous?

Back

It has one dominant and one recessive allele for a trait (e.g., Aa).

Front

What is a dominant allele?

Back

An allele that expresses its trait even in the presence of a recessive allele.

Front

What is a recessive allele?

Back

An allele that only expresses its trait when two copies are present (homozygous recessive).

Front

In a monohybrid cross, if a parent with a dominant phenotype is crossed with a parent with a recessive phenotype, what can be inferred about the dominant parent?

Back

The dominant parent is heterozygous for the trait.