Fig. 4.1 presents a Bengal tiger. The fur colour of the Bengal tiger is determined by one gene. The gene’s dominant allele gives orange fur. A single alteration in this gene creates a recessive allele, which gives white fur in tigers with the homozygous recessive genotype.
(a(i))[3]
State the meaning of the term gene.
(a(ii))[1]
State the word used for a change in a gene.
(b)[5]
Using $T$ (orange) and $t$ (white) to stand for the alleles that determine fur colour, draw a labelled genetic diagram to illustrate how two orange-furred tigers can produce white-furred offspring.
(c)[3]
Bengal tigers have dark stripes on their fur. Suggest why each of the following is true for the pattern of dark stripes: it is not influenced by whether the fur is orange or white; it is unique to each individual.
Worked solution & mark scheme
This 12-mark question has a full step-by-step worked solution and mark scheme. One marking point: “A segment/piece of DNA or chromosome” …