Pakistan MCQs

RNA polymerase copies one DNA strand into RNA.
In eukaryotes, transcription occurs mainly in the nucleus.

RNA polymerase binds near a gene and builds an RNA strand.
It uses complementary ribonucleotides.

RNA uses uracil instead of thymine.
Uracil pairs with adenine.

MRNA contains codons specifying amino-acid sequence.
It is translated by ribosomes.

TRNA has an anticodon and an amino-acid attachment site.
It matches amino acids to mRNA codons.

Hydrogen bonding produces specific pairing.
This complementarity supports accurate replication.

RRNA combines with proteins to form ribosomal subunits.
It helps catalyze peptide-bond formation.

ATP stores usable energy in phosphate bonds.
Hydrolysis of ATP powers many cellular processes.

Glycolysis breaks glucose into pyruvate.
It occurs in the cytosol and does not directly require oxygen.

Cellular respiration oxidizes fuel molecules.
Most ATP in aerobic cells is produced through oxidative phosphorylation.

The Krebs cycle oxidizes acetyl-CoA.
It produces reduced electron carriers and carbon dioxide.

Photosynthesis builds carbohydrates from carbon dioxide and water.
Light energy is captured by pigments such as chlorophyll.