Explanation

• A substitution mutation occurs when one nucleotide is replaced by another.
• It may be silent, missense or nonsense depending on its effect on the protein.
• Its consequences depend on the location and nature of the change.

Last verified on 07-11-2026

Explanation

• A locus is the specific physical position of a gene on a chromosome.
• Each gene occupies a particular locus on a chromosome.
• The plural of locus is loci.
• Different forms of the same gene, called alleles, occupy the same locus on homologous chromosomes.

Last verified on 07-11-2026

Explanation

• Plants need gas exchange for photosynthesis and respiration.
• Exchange of CO₂, O₂, and water vapor occurs through stomata on leaves.
• Stomata are tiny pores controlled by guard cells.

Additional information:

• Helps maintain internal water balance and gas diffusion.
• Essential for growth, energy production, and transpiration.

Last verified on 22-01-2026

Explanation

• Auxin promotes cell elongation in many plant tissues.
• It helps maintain apical dominance by suppressing lateral bud growth.
• It also participates in root formation and tropic responses.

Last verified on 07-11-2026

Explanation

• The pulmonary artery carries deoxygenated blood from the right ventricle of the heart to the lungs.
• In the lungs, blood releases carbon dioxide and absorbs oxygen.
• The pulmonary veins carry oxygenated blood from the lungs back to the left atrium of the heart.

Last verified on 07-11-2026