Genetics Vocab & Punnett Squares

Front

What is a genotype?

Back

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

Front

What does homozygous mean?

Back

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

Front

What does 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 an allele that expresses its trait even when only one copy is present (e.g., P in PP or Pp).

Front

What is a recessive allele?

Back

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

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

What is the probability of an offspring being purple if the parents are Pp and Pp?

Back

The probability is 75% for purple offspring (PP or Pp).

Front

What does it mean if an organism is homozygous dominant?

Back

It means the organism has two dominant alleles for a trait (e.g., AA).

Front

What does it mean if an organism is homozygous recessive?

Back

It means the organism has two recessive alleles for a trait (e.g., aa).

Front

In a Punnett Square, what does each box represent?

Back

Each box represents a possible genotype of the offspring resulting from the combination of parental alleles.