Genotypes and phenotypes

Front

What is a phenotype?

Back

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

Front

What is a genotype?

Back

A genotype is the genetic constitution of an individual, specifically the alleles present for a particular gene.

Front

Give an example of a phenotype.

Back

An example of a phenotype is having blue eyes.

Front

Give an example of a genotype.

Back

An example of a genotype is 'Aa', where 'A' is a dominant allele and 'a' is a recessive allele.

Front

What does heterozygous mean?

Back

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

Front

What does homozygous mean?

Back

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

Front

What is the probability of inheriting a recessive trait if both parents are heterozygous?

Back

The probability is 25%.

Front

What is the difference between dominant and recessive traits?

Back

Dominant traits are expressed in the phenotype even if only one allele is present, while recessive traits are expressed only when two recessive alleles are present.

Front

What is an allele?

Back

An allele is a variant form of a gene that can produce different traits.

Front

What does it mean if an organism is described as 'purebred'?

Back

A purebred organism has identical alleles for a specific trait, either homozygous dominant or homozygous recessive.