Entrance Exams
Govt. Exams
Frequency of heterozygotes = 2pq = 2(0.6)(0.4) = 0.48 in Hardy-Weinberg equilibrium.
Mutations are random, non-directed changes in DNA that provide genetic variation for natural selection to act upon. They're not inherently harmful or beneficial.
Industrial melanism is a classic example of directional selection where environmental change (pollution) favors one phenotype (dark color) over another.
Inbreeding increases homozygosity and decreases heterozygosity. The relationship is: Ht = H0(1-F), where heterozygosity decreases with increasing F.
In cave environments, eyes provide no selective advantage. Neutral mutations affecting eye development accumulate through genetic drift, resulting in eye loss.
If q² = 0.01, then q = √0.01 = 0.1. This is the frequency of the recessive allele.
Peripatric speciation occurs when a small population is geographically isolated, genetic drift acts strongly, leading to reproductive isolation and speciation.
In a normal test cross (Aa × aa), expected ratio is 1:1 (50% each). 40% dominant suggests some homozygous dominant (AA) offspring are dying, indicating lethal homozygous dominant allele.
Common descent refers to the principle that all organisms share evolutionary ancestry, a fundamental concept in evolutionary biology.
Disruptive selection eliminates intermediate phenotypes and favors both extreme phenotypes, increasing genetic variation.