Match the following and select the correct option:
(d) Detrivores, (e.g. earthworm) break down detritus into smaller particles. The species that invade a bare area in succession is called pioneer species. The products of ecosystem processes are termed as ecosystem services, e.g., healthy forest ecosystems purify air and water, mitigate droughts and floods etc. Natality refers to number of births during a given period in the population.
Rachel Carson's famous book "Silent Spring" is related to : [2015 RS]
(d) Rachel Carson’s book ‘Silent Spring’ reveals the harmful effect of DDT, a fatal pesticide. The writer opposed to chemical industry in U.S.A. This book influenced the national policy over pesticide use in many countries all over the world.
Vertical distribution of different species occupying different levels in a biotic community is known as:
(a) Stratification is the occurrence of vertical zonation in the ecosystem & indicates the presence of favorable environmental conditions, for e.g., trees occupy top vertical strata or layer of a forest, shrubs the second. Herbs & grasses occupy the bottom layers. It is absent or poor where environmental conditions are unfavorable, e.g. desert ecosystems have very few trees & shrubs.
The mass of living material at a trophic level at a particular time is called :
(c) Standing crop is the amount of living biomass in an ecosystem. It indicates theproductivity & luxuriance of growth. It is expressed in the form of number or biomass of organisms per unit area
In an ecosystem the rate of production of organic matter during photosynthesis is termed as:
(a) Gross Primary Productivity (GPP) is the rate of production of biomass or accumulation of energy by green plants per unit area per unit time. GPP depends on the chlorophyll content.
Secondary Succession takes place on/in :
(a) Secondary succession takes place in disturbed area having poor vegetation.
The following graph depicts changes in two populations (A and B) of herbivores in a grassy field A possible reason for these changes is that:
(a) The given graph illustrates that population B got success in the grassy field in comparison to population A.
During ecological succession:
(d) The gradual and predictable change, in the composition of species takes place in a given area during ecological succession.
Increase in concentration of the toxicant at successive trophic levels is known as :
(d) Biomagnification means an increase in concentration of toxins through the trophic levels of a food chain.
Industrial melanism is an example of :
(a) Industrial melanism occured in England due to industrial revolution. It caused black coating of moths for the adaptation in the present environment.
In which of the following both pairs have correct combination ?
(d) Carbon and Nitrogen are gaseous nutrient cycle. Sulphur and phosphorus are sedimentary nutrient cycle
During biological nitrogen fixation, inactivation of nitrogenase by oxygen poisoning is prevented by :
(d) Leghemoglobin prevents oxygen poisoning which causes inactivation of nitrogenase.
An association of individuals of different species living in the same habitat and having functional interactions is:
(a) Biotic community is an association of individuals of different species living in the same habitat and showing functional interactions.
Which of the following is a characteristic feature of cropland ecosystem ?
(b) Cropland ecosystem is largest anthropogenic ecosystem characterized by less diversity and high productivity
Which of the following would appear as the pioneer organisms on bare rocks?
(a) Lichens produce small amounts of carbonic acids from their "roots" and these slowly dissolve the rock, releasing nutrients. Other nutrients are obtained from water-borne or air-borne particles of both organic and inorganic materials. The body of a lichen contains an alga; this is able to photosynthesise sugars, some of which are passed on to the fungal component of the lichen. In return the alga gets a tiny but significant amount of shelter within the tissues of the lichen.
The term ecosystem was coined by
The term ecosystem was first used in 1935 in a publication by British ecologist Arthur Tansley.