Types of Monohybrid Cross – Post Lesson Practice

Copy and complete the following sentences.

1. A test cross is used to find the ______________ of an individual

showing a ______________ characteristic. In this type of cross the

individual with the unknown genotype is crossed with a

______________ recessive individual. (3)

2. In mice, the allele for black coat (B) is dominant to the allele for

brown coat (b). When a black mouse of unknown ______________

is used in a test cross, if all the offspring are black then its

genotype is ______________. If some of the offspring are brown

then its genotype is ______________. (3)

3. The human family tree diagram shows the inheritance of an allele

which causes albinism (a) . This allele is recessive to the normal allele

(A).

The genotype of individual P is _____. Of the four people

labelled in the family tree, only ______ could be a heterozygous

female. Individual R has a sister ______ and is married to

________. (4)

Total = 10