Question

Write short notes on the following: (i) Translation (ii) Hardy-Weinberg Principle.

Hint:

Translation: AUG start → codon-by-codon → stop codon. Hardy-Weinberg: p²+2pq+q²=1, no-evolution baseline.

Answer 1

Step 1: (i) Translation — definition:
Translation is the process by which the genetic message carried by mRNA is used to synthesise a polypeptide (protein), occurring on ribosomes in the cytoplasm.

Step 2: (i) Translation — process:
Translation begins when a charged tRNA recognises the start codon (AUG) on the mRNA at the ribosome (initiation). The ribosome then moves along the mRNA in the 5'→3' direction; successive tRNAs, each carrying a specific amino acid, pair their anticodon with the corresponding mRNA codon, and peptide bonds form between adjacent amino acids (elongation). This continues until a stop codon (UAA/UAG/UGA) is reached, at which point a release factor terminates translation and releases the completed polypeptide (termination).

Step 3: (ii) Hardy-Weinberg Principle:
The Hardy-Weinberg principle states that, in a large, randomly mating population with no mutation, migration, genetic drift or natural selection, the allele frequencies (p and q) and genotype frequencies remain constant from one generation to the next, described by the equation p² + 2pq + q² = 1. It is used as a baseline (null hypothesis) — any observed deviation from these expected frequencies indicates that evolution is acting on the population.

Final Answer:
(i) Translation converts the mRNA codon sequence into a protein via initiation, elongation and termination at the ribosome. (ii) The Hardy-Weinberg principle describes the constant allele/genotype frequencies of a non-evolving population (p²+2pq+q²=1), serving as a reference to detect evolutionary change.