MCQs

The prokaryotic 30S small ribosomal subunit contains the 16S rRNA molecule, which plays a key role in identifying the Shine-Dalgarno sequence.

The wobble hypothesis states that non-standard base pairing can occur between the third base of a codon and the first base of an anticodon.

Complementary bases within the single-stranded tRNA bend back and form hydrogen bonds, creating its characteristic shapes.

AUG is the universal start codon that codes for methionine in eukaryotes and formyl-methionine in prokaryotes.

Without a nuclear envelope separating DNA from ribosomes, prokaryotes can simultaneously transcribe and translate a genetic message.

The poly-A tail protects mRNA from 3' exonucleases, extending its operational lifespan within the cytoplasm.

Aminoacyl-tRNA synthetase is the specific enzyme that catalyzes the esterification of a specific amino acid to its cognate tRNA.

Written from the 3' to 5' direction (or 5'-CCA-3' read towards the 3' terminus), this terminal sequence attaches to the specific amino acid.

Introns are non-coding regions that must be excised, and exons are the coding sequences that are ligated together to form mature mRNA.

The large ribosomal subunit contains rRNA that acts as a ribozyme (peptidyl transferase) to catalyze peptide bond formation.

In eukaryotes, RNA Polymerase I is specialized for transcribing the major ribosomal RNA genes within the nucleolus.

The cloverleaf pattern arises due to localized base pairing within a single tRNA strand, creating loops and stems.

Chargaff's rules apply only to double-stranded nucleic acids where base pairing forces a 1:1 ratio between complementary bases.

The 5' cap protects the transcript from exonuclease degradation and assists in ribosome binding during translation initiation.

RNA polymerase adds new nucleotides exclusively to the free 3'-OH group of the growing RNA polymer, moving in a 5' to 3' direction.

A nucleoside consists only of a sugar and a base; adding a phosphate group converts it into a nucleotide.

Retroviruses lack DNA in their viral particles and utilize RNA to store their complete hereditary information.

Messenger RNA is rapidly degraded by ribonucleases after translation to control the rate of protein synthesis dynamically.

Transfer RNA contains an anticodon loop with three specific bases complementary to an mRNA codon.