Gause’s ‘Competitive Exclusion Principle’ states that -

The correct answer is Option (3) → Two closely related species competing for the same resources cannot co-exist indefinitely and the competitively inferior one will be eliminated eventually.

Option (1) Two closely related species competing for the different resources cannot co-exist indefinitely and the competitively inferior one will be eliminated eventually. — Incorrect. Species that use different resources do not compete at all, so neither is pushed out.

Option (2) Two distantly related species competing for the same resources cannot co-exist indefinitely and the competitively inferior one will be eliminated eventually. — Incorrect. The principle speaks of closely related species, because they have the most similar needs.

Option (3) Two closely related species competing for the same resources cannot co-exist indefinitely and the competitively inferior one will be eliminated eventually. — Correct. All three parts of the principle are present: closely related, same resources, inferior one eliminated.

Option (4) Two closely related species competing for the same resources can co-exist indefinitely and the competitively inferior one will be eliminated eventually. — Incorrect. It contradicts itself. If the inferior species is eliminated, the two cannot co-exist indefinitely.

Note: The same question was also asked in CUET (UG) 2025 on 23-05-2025 (Slot 2), and a similar question in CUET (UG) 2026 on 24-05-2026 (Slot 1), and in CUET (UG) 2025 on 02-06-2025 (Slot 2).

NCERT Extract:
Population Interactions – “… Gause’s ‘Competitive Exclusion Principle’ states that two closely related species competing for the same resources cannot co-exist indefinitely and the competitively inferior one will be eliminated eventually. This may be true if resources are limiting, but not otherwise. More recent studies do not support such gross generalisations about competition.”