IGCSE Biology Inheritance

Front

What term is used to describe a version of a gene?

Back

allele

Front

What term is used to describe an organism that carries two identical alleles for a gene?

Back

homozygous

Front

What term is used to describe an organism that carries two different alleles for a gene?

Back

heterozygous

Front

Observable features of an organism due to its genotype

Back

phenotype

Front

Gary and Fiona are both healthy but produce a child with a genetic disease caused by a recessive allele. Which of the following must be true? Options: The child could be heterozygous, Gary is homozygous and Fiona is heterozygous, Gary and Fiona are both homozygous, Gary and Fiona are both heterozygous.

Back

Gary and Fiona are both heterozygous

Front

Phenotype and genotype of a plant with two different alleles of gene G resulting in a green seed. Options: A, B, C, D.

Back

C

Front

What is the correct description of the genotype Aa?

Back

heterozygous, with two different alleles of the same gene

Front

What conclusion can be made about the genetic disease shown in the pedigree chart?

Back

It is caused by a dominant allele

Front

The pedigree chart shows the inheritance of a genetic disorder in a family.

What conclusion can be made about this genetic disease?

Back

It is caused by a recessive allele

Front

The pedigree chart shows the inheritance of a genetic disorder in a family.

It is caused by a recessive allele, h.

What conclusion can be made about the people in the chart?

Options: Peri must have the genotype HH, Sarah Jane must have the genotype Hh, Steven must have at least one H allele, Martha and Ian must have the genotype Hh

Back

Martha and Ian must have the genotype Hh