Eco system practice · Hard

Assertion: Capillary water is the readily available soil water to plants.
Reason: Capillary water is the thin film of water which is retained around soil particles.

The pyramid of number in grassland ecosystem is:

Consider the following statements about limitations of ecological pyramids
I. It never takes into account the same species belonging to two or more trophic levels
II. It assumes a simple food chain, which never exists in nature
III. In split of the vital role played by saprophytes/decomposers, they are not given any position in ecological pyramids
Which of the statements given above are correct?

Consider the following statements
I. In a food chain one organism holds only one position
II. In a food chain the flow of energy can be easily calculated
III. In food chain competition is limited to the members of same trophic level
Which of the statements given above are correct?

Identify the wrong pair of statements.
I) During plant succession, some species colonise an area and populations become more numerous,whereas
populations of other species decline and even disappear.

II) Both hydrarch and xerarch successions lead to mesic conditions.

III) Secondary succession is a slow process when compared to primary succession.

IV) In the successive seral stages, there is no change in the diversity of species of organisms.

Assertion: Insectivorous habitat of plants is to cope up ${N}_2$ deficiency.

Reason: Insectivorous plants are partly autotrophic and partly heterotrophic.

Statement I: The most productive area of the ocean is near the shore.
Statement II: Decomposition takes place at maximum rate on upper layer of soil.

Assertion: The conversion of productivity at next trophic level is $10 \%$.

Reason: Energy is lost in the respiration process.

The flow of DDT through the food chain, culminating in the deaths of cats in Borneo, represents the:

Blue whale, which inhabits Antarctica, has a requirement of more than a million calories per day. Which one of the following planktonic organisms forms the bulk of food to fulfill its caloric requirement?

Given below are two statements
Statement I: According to one estimate $4 \times 10^{13} \mathrm{~kg}$ of carbon is fixed annually in the biosphere through photosynthesis.
Statement II: Decomposers also contribute substaintially to $\mathrm{CO}_2$, pool by their processing of waste material and dead organic matter of land or oceans.
Choose the correct answer from the option given below:

Assertion: The number of species increases, the community biomass increases and the community's ratio of respiration to photosynthesis also increases. During an ecological succession.

Reason: The rate of photosynthesis of a community is almost equal to the rate of respiration, respiration, at climax community of an ecological succession.