Genetics: Alleles and Phenotypes

Front

What are genotypes?

Back

Genotypes are the genetic makeup of an organism, represented by the combination of alleles (e.g., Aa, BB, etc.).

Front

What are phenotypes?

Back

Phenotypes are the observable traits or characteristics of an organism, such as eye color or height, influenced by its genotype.

Front

How many alleles does each person carry for a trait?

Back

Each person carries 2 alleles for a trait, one inherited from each parent.

Front

What is an allele?

Back

An allele is a variant form of a gene that can produce different traits, such as brown or blue eyes.

Front

What does the term homozygous mean?

Back

Homozygous refers to having two identical alleles for a particular gene (e.g., AA or aa).

Front

What does the term heterozygous mean?

Back

Heterozygous refers to having two different alleles for a particular gene (e.g., Aa).

Front

What is a dominant allele?

Back

A dominant allele is one that expresses its trait even when only one copy is present (e.g., B in Bb).

Front

What is a recessive allele?

Back

A recessive allele is one that only expresses its trait when two copies are present (e.g., aa).

Front

What is a Punnett square?

Back

A Punnett square is a diagram used to predict the genetic outcomes of a cross between two organisms.

Front

If two brown-eyed parents (Bb) have a baby, what is the chance the baby is blue-eyed?

Back

The chance the baby is blue-eyed is 25%.