Genotype, Phenotype, & Punnett Squares

Front

What is a genotype?

Back

The possible combination of alleles in a gene.

Front

What is a phenotype?

Back

The physical expression of the genes, such as traits like hair color.

Front

What does a Punnett square illustrate?

Back

The possible genetic combinations of offspring from two parents.

Front

In a heterozygous genotype, which allele is expressed in the phenotype?

Back

The dominant allele.

Front

If B = brown fur and b = white fur, what is the genotype of a brown-furred animal that is heterozygous?

Back

Bb.

Front

What is the probability of offspring having white fur from two heterozygous parents (Bb x Bb)?

Back

25%.

Front

What does it mean if an allele is recessive?

Back

It is only expressed in the phenotype if two copies are present (e.g., bb).

Front

What is the genotype of an organism with two dominant alleles?

Back

It can be either homozygous dominant (BB) or heterozygous (Bb).

Front

What is the phenotype of an organism with the genotype 'tt'?

Back

Short (if T = tall and t = short).

Front

Which of the following is a phenotype: Aa, red hair, heterozygous, DNA?

Back

Red hair.