Ecosystem (Class - XII)
| Description: Ecosystem (Class - XII) | |
| Number of Questions: 15 | |
| Created by: Ratna Goswami | |
| Tags: Ecosystem (Class - XII) Ecosystem Biology Energy Flow Levels of Biological Organisation Adaptations to the Environment Ecological Succession Ecology Important Components of Ecosystem Nutrient Cycling |
What is the ecological behaviour in which the animals inhabit the trees called?
Which of the following energy productions is expected to have the highest value (gm/m2/yr) in a grassland ecosystem?
Which of the following statements are true about planktons?
A. They are drifting organisms. B. They have no locomotory organs. C. They may be found on the surface or in deep waters. D. They are mostly pelagic plants and animals. E. They also include some small fishes.
What is the correct sequence of ecological complexities?
The term ecosystem was given by
Which of the following types of successions occurs in an environment having the substrate devoid of vegetation?
The number of primary producers within a specified area would be maximum in a
An ecosystem is
Pond is an example of
Which of the following can be threats to the biodiversity of a geographical area?
- Global warming
- Fragmentation of habitat
- Invasion of alien species
- Promotion of vegetarianism
Directions: The question consists of two statements : Assertion and Reason. While answering the question you are required to choose any one of the following five responses.
(A) If both Assertion and Reason are true and the Reason is a correct explanation of the Assertion. (B) If both Assertion and Reason are true but Reason is not a correct explanation of the Assertion. (C) If assertion is true but the Reason is false. (D) If Assertion is false and Reason is true. (E) If both Assertion and Reason are false.
Assertion: Carbon cycle is a self-regulated feedback system. Reason: Increasing CO2 may disturb the climatic conditions of the world.
Match the type of speciation given in Column I with its characteristic given in Column II.
| Column I | Column II |
| A. Allopatric speciation | i. Formed due to several ecotypes having different adaptations |
| B. Sympatric speciation | ii. Formed due to genetic drift and natural selection |
| C. Adaptive radiation | iii. New species from spatially isolated populations |
| D. Gradual speciation | iv. Formed due to sudden appearance of reproductive isolation |
Directions: The question consists of two statements : Assertion and Reason. While answering the question you are required to choose any one of the following five responses.
(A) If both Assertion and Reason are true and the Reason is a correct explanation of the Assertion. (B) If both Assertion and Reason are true but Reason is not a correct explanation of the Assertion. (C) If Assertion is true but the Reason is false. (D) If Assertion is false and Reason is true. (E) If both Assertion and Reason are false.
Assertion: Pyramid of energy is always upright. Reason: Loss of energy always takes place from lower trophic level to higher trophic level.
Match the ecological terms in Column I with their characteristics given in Column II.
| Column I | Column II |
| A. Cline | i. It is an assemblage of closely related interbreeding individuals of a species. |
| B. Biotype | ii. Transient population between species having same genotypes and species having different genotypes |
| C. Ecotype | iii. Group of individuals of a species having same genotype |
| D. Deme | iv. Genetically different populations of a species colonising different specific habitat |
The correct path of energy flow in an ecosystem is