Answer:
Genotype ratio: 1 (RR) : 2 (RW) : 1 (WW)
Phenotype ratio: 1 Red : 2 Roan : 1 White
Explanation:
Codominance is a kind of inheritance pattern in which both alleles are equally dominant in a gene. This means that both alleles when in a heterozygous state will be simultaneously expressed. According to this question, allele for a red coat (R) and the allele for a white coat (W) results in offspring with a roan coat (RW) in cattle.
Hence, in a cross between a a roan cow (RW) and a roan bull (RW), the following gametes will be produced: R and W.
Using these gametes in a punnet square (see attached image), the offsprings with the following genotypes will be produced: RR, RW, RW, WW.
Therefore, based on the results of the cross;
Genotype ratio: 1 (RR) : 2 (RW) : 1 (WW)
Phenotype ratio: 1 Red : 2 Roan : 1 White
Gel electrophoresis is a technique used to separate DNA fragments according to their size. This is from Khan academy so I believe it is reliable.
The answer is A, anti-fungal drugs.
According to the passage, "but if the problem persists, see a doctor who can prescribe anti-fungal drugs". In additional, at the beginning of the passage, it already stated that athlete's foot is caused by a fungus, so we can sure that the answer is A.