A. The most valuable and the richest ecosystems on earth
B. They play a critical pat in the earth’s life support systems and house 50% and possibly as much as 90% of all the species on earth
C. They are a key storehouse of foods, oils and minerals and source of ingredients that make up a range of medical treatments
D. All of the above
Related Mcqs:
- The most striking difference between tropical rain forests and temperate forests is that:
A. The tropical rain forests have preponderance of angiosperms while the temperate ones have preponderance of gymnosperms
B. The trees of temperate forests are taller than these of tropical rain forests
C. Plants of temperate forests are comparatively more mesophytic
D. Tropical forests are comparatively homogenous - Tropical littoral and swamp forests is/are:
A. Tidal Swamp Forests
B. Littoral Grassland
C. Both (a) & (b)
D. None of these - Dry sub-tropical broad-leaved forests having:
A. Low forest of branchy trees forming a canopy
B. Varying in density from complete closure
C. Under the most favourable conditions to scattered single trees or groups on the driest sites
D. Typically field in with a shrub growth which similarly varies in density
E. All of the above - Tropical thorn forests are these:
A. Which thorny usually hard wooded species predominate, Acacia spp. Being particularly characteristic
B. The trees usually have short boles and low branching crowns which rarely meet except on exceptionally favourable spots
C. Both (a) & (b)
D. None of these - These are generally, but not always, developed above the birch zone and in patches, sometimes extensive, within it, probably conditioned by edaphic and biotic factors, in Kashmir, Gilgit, Chitral and Hazara. This type ascends normally to ______ or more above the sub-alpine forests and climate must be similar but more severe than in sub-alpine forests:
A. 140 m
B. 150 m
C. 160 m
D. 170 m - The moist tropical deciduous forest biomes show predominace of plants like:
A. Larix and Abies
B. Zizyphus and Butea
C. Shorea and Tectona
D. All of these - Generally seeds of species growing in cool temperate and dry tropical areas need some sort of pre-sowing treatment is/are:
A. Weathering: Seed is exposed to sunlight, wind and rain
B. Mechanical treatment: In order to break hard seed coat seed is beaten or crushed
C. Fire treatment: Seed is covered with grass etc. And grass is put on fire
D. Water treatment: Seed is soaked in hot or cold water for some hours or even days before sowing
E. All of the above - Tropical dry deciduous forest having:
A. An open rather low forest composed
B. A few trees of the thorn forest type
C. With a predominantly deciduous shrub layer
D. All of the above - Plants, such as Prosopis, Acacia, and Capparis represent examples of tropical:
A. Grasslands
B. Evergreen forests
C. Deciduous forests
D. Thorn forests - Tropical dense forest is due to:
Tropical dense forest is due to:
A. Low temperature and excess rain
B. High temperature and excess rain
C. High temperature and lesser rain
D. Wild animals (tigers, lions, bears etc.)
The correct answer to the question: "Tropical rain forests are:" is "All of the above".
