Govt. Exams
Entrance Exams
1:1 ratio indicates heterozygous tall plant (Tt) crossed with homozygous recessive dwarf (tt).
'Fitness' in evolutionary context means reproductive success—leaving maximum viable offspring, not physical strength.
Female XWXw × Male XwY produces: XWXw (red female), XwXw (white female), XWY (red male), XwY (white male). Correcting: produces XWXw (red female) and XwY (white male) primarily.
Dark moths increased in polluted areas not by developing dark color, but because pre-existing dark variants had survival advantage.
Genetic drift causes random, unpredictable changes in allele frequencies, particularly significant in small isolated populations.
F1 is Rr (all round). F2: 1 RR : 2 Rr : 1 rr. Among round seeds (3 total), only 1 is homozygous RR, so 1/3.
Frequency of Aa = 2pq where p = 0.6 and q = 0.4; 2(0.6)(0.4) = 0.48
Silent mutations occur in the third position of codons (wobble base), changing the DNA sequence but not the amino acid due to codon degeneracy.
Female XwXw × Male XWY produces: XWXw (red female), XwXw (white female), XWY (red male), XwY (white male). 50% of total offspring are white-eyed.
Multiple lines of evidence support evolution: homologous structures indicate common ancestry, vestigial organs show evolutionary remnants, and fossil records show gradual changes over time.
