GEGE2001 Quiz 1

In a pedigree, autosomal recessive inheritance for a rare trait is characterised by the following:

A test cross refers to a:

A cross between two different pure-breeding breeds of “coloured wing parrots” (red wing x white wing) gave the following progenies in the F1 and F2 generations: F1 = all pink; F2 = ¼ red, ½ pink, ¼ white. These results indicate that:

The principle of independent assortment means that:

If a χ2 (chi-square) test of a genetic ratio gives a Probability of 0.02 (2%), then:

Dominance is the determination of the phenotype by:

Complete linkage means that:

From a cross of sheep (Rr female parent, rr male parent), the progeny will be of genotype:

A cross is made between two pure breeding cattle breeds, where one breed is resistant to a tick species due only to a dominant allele of a gene for resistance, and the other breed is resistant only due to a recessive allele at a different gene to the first for resistance. Both genes are autosomal. The F1 between the breeds was resistant; what is the expected ratio of resistant to susceptible cattle in the F2 generation assuming independent assortment of the two autosomal genes? (Hint: once a cattle individual is resistant because of its genotype at one of the genes, having resistance determined by the other gene does not give increased resistance, i.e. there are only 2 phenotypes: resistant and susceptible)

Repulsion double heterozygotes: