Biology 0610 · IGCSE · Monohybrid inheritance

Monohybrid inheritance — practice question

A pea plant species can produce peas that are either green or yellow. One gene controls the colour of the peas. The dominant allele for yellow peas is shown by the letter G, whereas the recessive allele for green peas is shown by g.
(a(i))[3]

Apply your own knowledge together with this information to complete Table 3.1.

(a(ii))[2]

Complete the genetic diagram in Fig. 3.2 to show the outcome of the cross. State the ratio of yellow offspring to green offspring.

(b(i))[1]

State how many people have cystic fibrosis.

(b(ii))[1]

Identify the letter for a person who must have a heterozygous genotype.

(b(iii))[1]

Circle the probability that person U will have a child with cystic fibrosis: 0%, 25%, 50%, 75% or 100%.

Worked solution & mark scheme

This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: homozygous recessive genotype $\text{gg}$

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