AP Biology Genetics Problems

Front

What is the definition of a dominant trait in genetics?

Back

A dominant trait is a genetic trait that is expressed in the phenotype even when only one copy of the allele is present.

Front

What is the definition of a recessive trait in genetics?

Back

A recessive trait is a genetic trait that is only expressed in the phenotype when two copies of the allele are present.

Front

What does homozygous mean?

Back

Homozygous refers to having two identical alleles for a particular gene.

Front

What does heterozygous mean?

Back

Heterozygous refers to having two different alleles for a particular gene.

Front

In a Punnett square, what does each box represent?

Back

Each box in a Punnett square represents a possible genotype of the offspring from the parental genotypes.

Front

What is the probability of obtaining a homozygous recessive offspring from a cross between two heterozygous parents (Aa x Aa)?

Back

The probability is 25%.

Front

If black fur (B) is dominant over white fur (b), what is the genotype of a guinea pig with black fur?

Back

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

Front

What is the expected phenotypic ratio of a dihybrid cross (AaBb x AaBb)?

Back

The expected phenotypic ratio is 9:3:3:1.

Front

What is the chance of producing an offspring with the genotype aabb from parents Aabb and aaBb?

Back

The chance is 25%.

Front

What is the definition of a genotype?

Back

A genotype is the genetic makeup of an organism, represented by the alleles it possesses.