Consider the following statements: 1) Biodiversity is normally greater in the lower latitudes as compared to the higher latitudes. 2) Along the mountain gradients, biodiversity is normally greater in the lower altitudes as compared to the higher altitudes. Which of the statements given above is/are correct?

Both statements are correct, so the answer is C. Statement 1 describes the latitudinal diversity gradient: species richness rises as we move from the poles towards the equator. Tropical regions have stable climates, high solar energy input, high primary productivity, long periods free of glaciation, and more niches, which together support more species. The Amazon and the Western Ghats are classic examples, while tundra and boreal regions near the poles are poor in species.

Statement 2 describes the altitudinal gradient. Along a mountain slope, species numbers generally fall as altitude increases, because temperature drops, growing seasons shorten, and habitat area shrinks towards the summit. Some mid-elevation slopes show a hump-shaped pattern, which is why the word 'normally' is used in the statement.

• Option A is wrong because statement 2 is also correct.
• Option B is wrong because statement 1 is also correct.
• Option D is wrong because both statements hold as general patterns.

Core concept: latitudinal and altitudinal diversity gradients, linked to climate, productivity and habitat area. This sits under Environment and Ecology and connects to Mains questions on biodiversity conservation and species shifting upslope and poleward under climate change.

Trap: candidates often reject statement 2 because they assume diversity peaks at mid-altitudes, or they read 'normally' as making the statement false. The general trend is what matters here.