Genetics

Front

What is an allele?

Back

An allele is a variant form of a gene that determines a specific trait. Each individual inherits two alleles for each gene, one from each parent.

Front

How many alleles does an offspring receive from each parent?

Back

One allele from each parent.

Front

What is a phenotype?

Back

A phenotype is the observable physical or biochemical characteristics of an organism, as determined by both genetic makeup and environmental influences.

Front

Give an example of a phenotype.

Back

Blue eyes.

Front

What is a genotype?

Back

A genotype is the genetic constitution of an individual, represented by the alleles inherited from the parents.

Front

What does homozygous mean?

Back

Homozygous refers to having two identical alleles for a particular gene, such as 'YY' or 'yy'.

Front

What does heterozygous mean?

Back

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

Front

What is the significance of recessive genes?

Back

Recessive genes only express their trait when two copies are present (homozygous). If only one copy is present (heterozygous), the dominant trait will be expressed.

Front

What is a Punnett square?

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

If one parent is homozygous dominant (SS) and the other is homozygous recessive (ss), what is the probability of offspring having the dominant trait?

Back

100% of the offspring will have the dominant trait.