In investigations into genetic inheritance in Syrian hamsters (Mesocricetus auratus), breeders studied coat colour. A black coat is dominant over an albino (white) coat.
Use the following symbols for the alleles:
A pure-breeding black hamster (Hamster 1, genotype BBBBBB) was crossed with an albino hamster (Hamster 2). All the offspring (F1 generation) had black coats.
Two of these F1 offspring (Hamster 3 and Hamster 4, both heterozygous) were then crossed.
State the genotype of Hamster 2.
Complete the cross to find the male gametes and the four offspring genotypes (A, B, C, and D) represented in the table below:
| Female | BBB | bbb |
|---|---|---|
| Male ? | A | B |
| Male ? | C | D |
Determine the expected phenotypic ratio of black coat hamsters to albino coat hamsters in the offspring.
What does the term 'heterozygous' mean?
State one reason why the importance of Mendel's work on genetics was not recognized by other scientists in 1866.
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.