Answer:
4
Explanation:
According to Mendel's law of purity of gametes, each gamete contains single allele for a gene. The alleles of a gene segregate during gamete formation and each gamete has one allele for a gene irrespective of the total number of alleles for a gene.
If the gene for skin color in a fish species has four alleles, an individuals fish would have only two alleles which in turn would segregate during gamete formation.
Since there are four different alleles of the gene (let's assume a,b,c, and d), total possible gametes produced by this organism will be = 4. A gamete can have one of the total 4 alleles making total 4 types of the gametes each with a or b or c or d allele.
Answer:
The homozygous dominant phenotype is higher than expected, indicating that evolution has occurred.
Explanation:
At the start there are 200 fishes in the pond, 100 of them are AA(50%) and 100 of them are aa(50%). Using the Hardy-Weinberg Equilibrium equation we can say that the gene frequency is
A=0.5
a=0.5
With those frequency, the expected percentage of offspring with dominant genotype will be:
AA= 0.5 * 0.5 = 0.25 = 25%
The number of homozygous dominant found is 35% which is higher than expected (25%). Higher homozygous dominant frequency than expected means the Hardy-Weinberg Equilibrium is changed. In this case, evolution probably the cause that shifts the gene frequency.
