Govt. Exams
Entrance Exams
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.
UAA is a stop codon. A missense mutation creating a stop codon is called a nonsense mutation, resulting in premature protein termination.
Cross: XAXa (female) × XaY (male). Male offspring: 1/2 XAY (red) and 1/2 XaY (white). Therefore, 50% white-eyed males.
Microevolution involves allele frequency changes within a population over relatively short periods. Macroevolution is long-term divergence into new species.
A color-blind female must be homozygous recessive (XbXb) because she has only two X chromosomes. She has two copies of the recessive allele.
Ligers are viable hybrids but sterile, representing post-zygotic isolation where hybrids have reduced fitness or viability.
