Answers to genetics test. One . Duroc – bbww Hampshire – BBWW F1 - BbWw. One . b) For achieved Pure breeding means that the individual has a homozygous genotype / can produce only one type of allele.
Duroc – bbww
Hampshire – BBWW
F1 - BbWw
b) For achieved Pure breeding means that the individual has a homozygous genotype / can produce only one type of allele.
For Merit Homozygous parent can pass on only one type of allele (for that trait) to its offspring (there is NO variation in the alleles) so offspring have same alleles and phenotype as the parent.
c) Someone draw on the board
(Gametes correct for A, whole punnet correct for M)
d) For achieved One of bbWWor bbWw
For Merit Both (above) and no other genotype given.
e) For achieved 3/16 or 3:15 or correct decimal or correct %
f) For achieved Gives genotypes as bbWW and describes breeding suspect pigs with recessive genotype (bbww) pigs and check whether offspring have white bands or are solid red only.
For M As for A, and also:
For E Need M + explanation of the need for several breedings. Eg. If no solid red (bbww) pigs occur in the large numbers of offspring, then the suspect pig is (almost certainly) bbWW so pure breeding.
Answer must be supported with correct punnet squares (bbWw x bbww) and (bbWW x bbww)
b) For A Mutation must occur in gamete producing cells for it to enter the gene pool.
For M If the gamete with the mutation is fertilised and the offspring produced is viable, then the mutation will enter the gene pool of the population.
c) For A Describes natural selection as causing:
For M Explains one of:
b) For A Describes inbreeding:
b) For M Explains inbreeding: