In guinea pigs, the inheritance of coat texture is controlled by a gene with two alleles. The allele for a rough coat (RRR) is dominant to the allele for a smooth coat (rrr).
In a first cross, a heterozygous parent mates with a homozygous recessive parent.
State the genotypes of both parents.
State the potential phenotypes of the offspring from this cross.
In a second cross, two heterozygous guinea pigs (RrRrRr) mate.
State all the possible genotypes of their offspring.
Calculate the probability that a single offspring from this second cross will have a rough coat. Give your answer as a percentage, fraction, or decimal.
66 exam-style questions on Edexcel IGCSE Biology Inheritance. Each one has a worked solution and a mark scheme showing where the marks go.