Entrance Exams
Govt. Exams
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.
Phenotypic plasticity is the ability of a single genotype to produce different phenotypes in response to environmental variation (e.g., hydrangea flower color).
Natural selection is the non-random differential reproduction of organisms with traits that increase fitness. Organisms with advantageous traits leave more offspring.
Silent mutation occurs in the third position of a codon and does not change the amino acid due to degeneracy of genetic code. No phenotypic effect.
Cross: XᴮXᵇ × XᴮY produces sons: 50% XᴮY (normal) and 50% XᵇY (color blind). Therefore, 50% of sons are color blind.
Haemophilia A (clotting factor VIII deficiency) is X-linked recessive. Affected males (XᵃY) pass the allele to all daughters but no sons.