Suppose that a dominant allele (P) codes for a polka-dot tail and a recessive allele (p) codes for a solid colored tail. In addi
tion, suppose that a dominant allele (L) codes for long eyelashes and a recessive allele (l) codes for short eyelashes. If two individuals heterozygous for both traits (tail color and eyelash length) mate, what's the probability of the phenotypic combinations of the offspring? A. 1:1 ratio (half are polka-dot tails and short eyelashes; half are solid tails and long eyelashes)
B. 1:1 ratio (half are polka-dot tails and long eyelashes; half are solid tails and short eyelashes)
C. 9:3:3:1 ratio (9 polka-dot tails and short eyelashes, 3 polka-dot tails and long eyelashes, 3 solid tails and short eyelashes, 1 solid tail and long eyelash)
D. 9:3:3:1 ratio (9 polka-dot tails and long eyelashes, 3 polka-dot tails and short eyelashes, 3 solid tails and long eyelashes, 1 solid tail and short eyelash)
I believe the answer is c) 9:3:3:1 ratio (9 polka-dot tails and short eyelashes, 3 polka-dot tails and long eyelashes, 3 solid tails and short eyelashes 1 solid tail and long eyelash)
Genetic drift is change in allele frequencies in a population from generation to generation that occurs due to chance events
The genetic drift occurs due to random fluctuation of any allele in a gene pool and is more efficient in small population
The founder effect and the bottleneck effect are cases in which a small population is formed from a larger population which means they may experience strong drift for generations
In founder effect a genotype from a homogeneous gene pool migrate to a newer habitat and colonize there and form a newer community which leads to the genetic drift to the original population, speciation which occurs in this effect is the peripatric speciation
In bottleneck effect the elimination of inferior genotype from a homogeneous gene pool occurs due to the strong selection pressure and changing environmental conditions which leads to genetic drift and a only a few most adapted genotype survives and flourish
Natural Selection
Natural selection is a selection pressure which operates in a population and allow the best fitted genotype to survive in changing environmental conditions and eliminate the other genotype which are not fit
Genetic drift, mutation and sexual selection are important causes of natural selection
Directional natural selection favours the superior genotype and eliminate the inferior and intermediate genotype, in the history of evolution the most common natural selection is directional natural selection
Stabilizing natural selectionfavours the intermediate genotype but eliminates the extreme genotype
Bidirectional natural selection favours the extreme genotypes but eliminate the intermediate genotypes
