During adverse season, therophytes survive by
[1997]
The rate at which light energy is converted to the chemical energy of organic molecules is the ecosystem’s
[1998]
1 Crore+ students have signed up on EduRev. Have you? Download the App |
Approximately how much of the solar energy that falls on the leaves of a plant is converted to chemical energy by photosynthesis?
Upper part of sea / aquaticeco system contains
[1988]
What is true of ecosystem?
[1988]
In an ecosystem, which one shows one-way passage
[1988]
Sudden mass killing of fishes is likely in
[1999]
Pneumatophores are characteristic of plants growing in
[2000]
The greatest biomass of autotrophs in the oceans is that of
[2000]
Bamboo plant is growing in a fir forest then what will be the trophic level of it?
[2002]
Which of the following is expected to have the highest value (gm/m2/yr) in a grassland ecosystem?
[2004]
If by radiation all nitrogenase enzymes are inactivated, then there will be no
[2004]
An ecosystem which can be easily damaged but can recover after some time if damaging effect stops will be having
[2004]
Barophilic prokaryotes:
[2005]
More than 70% of world’s freshwater is contained in:
[2005]
Which one of the following is not used for construction of ecological pyramids?
[2006]
Which one of the following ecosystem types has the highest annual net primary productivity?
[2007]
About 70% of total global carbon is found in
[2008]
The slow rate of decomposition of fallen logs in nature is due to their
[2008]
Consider the following statements concerning food chains
(a) removal of 80% tigers from an area resulted in greatly increased growth of vegetation
(b) removal of most of the carnivores resulted in an increased population of deers
(c) the length of food chains is generally limited to 3-4 trophic levels due to energy loss
(d) the length of food chains may vary from 2 to 8 trophic levels
Which two of the above statements are correct?
[2008]
The correct sequence of plants in a hydrosere is:
[2009]
Which one of the following types of organisms occupy more than one trophic level in a pond ecosystem?
[2009]
Study the four statements (a–d) given below and select the two correct ones out of them:
(i) A lion eating a deer and a spar row feeding on grain are ecologically similar in being consumers
(ii) Predator star fish Pisaster helps in maintaining species diversity of some invertebrates
(iii) Predators ultimately lead to the extinction of prey species
(iv) Production of chemicals such as nicotine, strychnine by the plants are metabolic disorders The two correct statements are:
[2010]
The biomass available for consumption by the herbivores and the decomposers is called:
[2010]
Mass of living matter at a trophic level in an area at any time is called
[2011]
86 videos|294 docs|184 tests
|