Assertion: In tropical rain forests, O-horizon and A-horizon of soil profile are shallow and nutrient-poor.
Reason: Excessive growth of micro-organisms in the soil depletes its organic content.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
B.
If both assertion and reason are true but reason is not the correct explanation of assertion
A cross section of well developed soil shows more or less distinct layers called horizons.
0- horizon is the topmost layer of soil and A-horizon comes below O horizon. In the topmost layer, vegetation grows and various biological activities takes place. Tropical rain forests are found in tropical zone of the world and are characterized by very high temperature and abundance of rainfall. Soil in these area arc red latosols and are exceedingly thick. Leaching of minerals from the top soil occurs rapidly but cycling of nutrients also occur here. The laterite soils arc generally infertile because of intensive leaching and not due to growth of micro-organism.
Given below is one of the types pyramids.
This type represents
pyramid of numbers in a grassland
pyramid of biomass in a fallow land
pyramid of biomass in a lake
energy pyramid in a spring
Biological Oxygen Demand (BOD) is a measure of
industrial wastes poured into water bodies
extent to which water is polluted with organic compounds
amount of carbon monoxide inseparably combined with haemoglobin
amount of oxygen needed by green plants during night
Assertion : In a food chain members of successive higher levels are fewer in number.
Reason : Number of organisms at any trophic level depends upon the availability of organisms which serve as food at the lower level.
If both Assertion and Reason are true and the reason is the correct explanation of the assertion
If both Assertion and Reason are true but the reason is not the correct explanation of the assertion
If Assertion is true statement but Reason is false
If both Assertion and Reason are false statements
Acid rain is due to increase in atmospheric concentration of :
Ozone
CO2 and CO
SO3 and CO
SO2 and nitrogen oxide
Which of the following factor is biotic
Photoperiod
CO2 content to the soil
Texture and porosity of soil
Rainfall
The pyramid of energy-in a forest ecosystem is
always upright
always inverted
both (a) and (b)
none of the above
Identify which one of the following is an example, of incomplete ecosystem?
Grassland
Cave
River
Wetland
