Genetics

Front

What is an allele?

Back

An allele is a variant form of a gene that can produce different traits. For example, a gene for flower color may have a purple allele and a white allele.

Front

How many alleles does an offspring receive from each parent?

Back

An offspring receives one allele from each parent for a specific trait.

Front

What is the difference between genotype and phenotype?

Back

Genotype refers to the genetic makeup of an organism (the alleles it carries), while phenotype refers to the physical expression of those genes (how the organism appears).

Front

What is a dominant allele?

Back

A dominant allele is an allele that expresses its trait even when only one copy is present. For example, in pea plants, the allele for tall plants is dominant.

Front

What is a recessive allele?

Back

A recessive allele is an allele whose trait only shows up when two copies are present (i.e., when no dominant allele is present).

Front

What is a Punnett Square used for?

Back

A Punnett Square is a diagram used to predict the outcome of a genetic cross by showing the possible combinations of alleles from the parents.

Front

What is the phenotypic ratio in a cross between two heterozygous plants for a dominant trait?

Back

The phenotypic ratio is 3:1, meaning three offspring will show the dominant trait for every one that shows the recessive trait.

Front

What does homozygous mean?

Back

Homozygous refers to having two identical alleles for a particular gene, such as AA or aa.

Front

What does heterozygous mean?

Back

Heterozygous refers to having two different alleles for a particular gene, such as Aa.

Front

What is the role of DNA in genetics?

Back

DNA carries the genetic information necessary for the growth, development, and functioning of living organisms.