IGCSE Biology - Monohybrid Inheritance

What term is given to an organism that carries two identical alleles of a gene

• heterozygous

• homozygous

• dominant

• recessive

What term is given to an organism that carries two different alleles of a gene

• homozygous

• dominant

• heterozygous

• recessive

What term is used to describe the alleles that a person carries for a gene

• genotype

• dominant

• phenotype

• recessive

What term is used to describe the observable features that an organism has due to the alleles that it carries?

• genotype

• inheritance

• phenotype

• dominant characteristic

What word is used to describe the transmission of genetic information from generation to generation?

• phenotype

• genotype

• allele

• inheritance

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

• genotype

• phenotype

• allele

• chromosome

What word is used to describe a thread-like structure of DNA that carries genes?

• nucleus

• chromosome

• genotype

• phenotype

Which of the following is true of a dominant allele?

I. it is always expressed if it is present

II. two copies are needed to show its feature

III. it always causes a genetic disease

• I only

• I and II only

• II only

• I and III only

Which of the following is true of a recessive allele?

I. it is only expressed if the dominant allele is absent

II. two copies are needed to show its feature

III. it always causes a genetic disease

• I only

• I and II only

• II only

• I, II and III

When carrying out a test cross, what is the organism of unknown genotype always crossed with?

• homozygous dominant (e.g. RR)

• heterozygous (e.g. Rr)

• homozygous recessive (e.g. rr)

• all three of these can be used