Practice Questions

Silent mutations take advantage of the redundancy of the genetic code, where multiple codons translate into the same amino acid.

Each G-C pair has three hydrogen bonds (5×3=15) and each A-T pair has two (3×2=6). The total is 15+6=21.

Alleles are alternative nucleotide variants of a gene found at the same chromosomal locus, governing variations of the same trait.

To form proper hydrogen bonds across the core, the twin strands must line up in opposite orientations, pairing a 5' end with a 3' end.

A locus refers to the fixed geographic coordinate or position where a gene or genetic marker resides on a chromosome.

Coined by Francis Crick, the Central Dogma outlines the unidirectional transfer of functional sequence information during gene expression.

Lacking a 2'-OH group allows deoxyribose to prefer a C2'-endo sugar pucker, which drives the flexible, uncrowded B-DNA geometry.

An operon is a functional genetic unit found in bacteria that allows several genes in a shared pathway to be transcribed together as a single mRNA.

Heating a DNA sample provides enough thermal energy to break the hydrogen bonds and base-stacking interactions, separating the strands.

A nonsense mutation introduces a premature stop signal (UAA, UAG, or UGA), halting translation and yielding a truncated protein.