Biology 0610 · IGCSE · Monohybrid inheritance

Monohybrid inheritance — practice question

Hair length in cats is determined by a single gene. The allele for short hair is dominant - H. The allele for long hair is recessive - h. Fig. 3.1 shows a photograph of two cats.
(a(i))[3]

Table 3.1 displays some genetic and physical characteristics of the cats in Fig. 3.1. Complete Table 3.1.

(a(ii))[1]

State the genotype of a pure-breeding cat with short hair.

(a(iii))[1]

Two cats with genotypes HH and hh were crossed. Predict the percentage of offspring that are heterozygous.

(b)[2]

The statements refer to continuous variation or discontinuous variation. Identify which type of variation each statement describes. Write C for continuous variation or D for discontinuous variation in the spaces provided. Height is an example of this type of variation. There are no intermediate phenotypes with this type of variation. This type of variation results in a limited number of phenotypes.

(c)[2]

A student defined variation as: ‘the similarities between individuals of the same kingdom’. Identify the two incorrect words in the student's definition.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: Cat A should be recorded as long hair with genotype hh.

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