Skip to content
Question 52 of 70

Q.(a) How does Hardy-Weinberg's expression (p^2 + 2pq + q^2 = 1) explain that genetic equilibrium is maintained in a population ? List any four factors that can disturb the genetic equilibrium. OR

(b) Explain any five bacterial disease.
Tamil Nadu DgeTamil Nadu HSC (DGE) Board 2022Subjective· 5mImportance★★★★★
74% · 52/70 Questions
🔒 Locked · start free trial →

You're viewing a preview — the full solution, concept, methods & PYQ mapping are locked.

Start your 14-day free trial to unlock the full solution →

(a) Hardy-Weinberg equilibrium means allele and genotype frequencies stay constant across generations under ideal conditions; mutation, migration, genetic drift and selection disturb it. (b) Typhoid, cholera, tuberculosis, diphtheria, and pertussis/whooping cough are five major bacterial diseases.

(a) The Hardy-Weinberg principle states that, in a large, randomly mating population with no mutation, no migration, and no natural selection, the allele frequencies (p for the dominant allele, q for the recessive allele, where p + q = 1) remain constant from generation to generation, and consequently the genotype frequencies also remain constant, distributed as p^2 (homozygous dominant), 2pq (heterozygous), and q^2 (homozygous recessive), summing to 1. Because these ratios do not change over successive generations under the stated ideal conditions, the population is said to be in genetic (Hardy-Weinberg) equilibrium, meaning no evolutionary change is occurring at that locus. In reality, however, populations rarely stay in perfect equilibrium because certain factors act to change allele frequencies and drive evolution: mutation introduces new alleles into the gene pool; gene migration (gene flow), the movement of individuals (and their alleles) into or out of a population, alters local allele frequencies; genetic drift, random chance fluctuations in allele frequency (especially significant in small populations, e.g., founder effect, bottleneck effect); and natural selection, the differential survival and reproduction of individuals with certain genotypes due to their fitness advantage. (Non-random mating is another factor sometimes listed.) Any of these forces disturbs the Hardy-Weinberg equilibrium and results in evolutionary change in the population.

…

Unlock everything free for 14 days

  • Full step-by-step solutions
  • Concept-first explanations
  • Methods, shortcuts & mistakes
  • PYQ mapping + timed mock tests

Full access for 14 days. No credit card required.