In mice, the allele for normal pigmented fur (AAA) is dominant over the allele for albino (white) fur (aaa).
A researcher crossed a homozygous normal-pigmented mouse (genotype AAAAAA) with a homozygous albino mouse. All resulting F1F_1F1 offspring had normal-pigmented fur.
State the genotype of the homozygous albino parent mouse.
Two of the F1F_1F1 offspring mice (both with genotype AaAaAa) are crossed. Complete the genetic diagram (Punnett square) below by determining the missing genotypes of the offspring.
Male gamete: AMale gamete: aFemale gamete: AAA(i)Female gamete: a(ii)(iii) \begin{array}{c|c|c} & \text{Male gamete: } A & \text{Male gamete: } a \\\hline \text{Female gamete: } A & AA & \text{(i)} \\\hline \text{Female gamete: } a & \text{(ii)} & \text{(iii)} \end{array} Female gamete: AFemale gamete: aMale gamete: AAA(ii)Male gamete: a(i)(iii)Identify the genotypes for (i), (ii), and (iii).
State the expected ratio of normal-pigmented mice to albino mice in the offspring of this cross in its simplest form.
76 exam-style questions on AQA GCSE Biology 6.1 Reproduction, covering 6.1.1 Sexual and asexual reproduction, 6.1.2 Meiosis, 6.1.3 Advantages and disadvantages of sexual and asexual reproduction, 6.1.4 DNA and the genome, 6.1.5 DNA structure, 6.1.6 Genetic inheritance, 6.1.7 Inherited disorders, and 6.1.8 Sex determination. Each one has a worked solution and a mark scheme showing where the marks go.