Ecosystem - Chapter End Test | Class-12 Biology

CLASS-XII    BIOLOGY     CHAPTER END TEST

CHAPTER-12: ECOSYSTEM

Q.1	If the carbon atoms fixed by producers already have passed through three species, the trophic level of the last species would be. a. scavenger b. tertiary producer c. tertiary consumer d. secondary consumer	1M
Q.2	Among the following bio-geo-chemical cycles which one does not have losses due to respiration? a. Phosphorus b. Nitrogen c. Sulphur d. All of the above	1M
Q.3	Approximately how much of the solar energy that falls on the leaves of a plant is converted to chemical energy by photosynthesis? a. Less than 1% b. 2-10% c. 30% d. 50%	1M
Q.4	Which of the following is not a producer? a. Spirogyra b. Agaricus c. Volvox d. Nostoc	1M
Q.5	Why is the pyramid of energy always upright?	2M
Q.6	Differentiate between primary and secondary succession.	2M
Q.7	Explain phosphorous cycle in terrestrial exosystem.	3M
Q.8	An ecosystem is a complex in which habitat, plants, and animals are considered as one interesting unit, the materials, and energy of one passing in and out of the others. The concept of the ecosystem was first put forth by A.G. Tansley (1935). An ecosystem is the major ecological unit. It has both structure and function. The structure is related to species diversity. Generally, ecosystems consist of two basic components- abiotic and biotic. The decomposers play a very important role in maintaining the dynamic nature of the ecosystem. Ecosystems may be Terrestrial or aquatic types. The primary function of any ecosystem is the exchange of energy from one life form to another, which eventually runs in a circle and sustains the entire life of the planet. Which one of the following is not a component of the ecosystem a- Productivity b- Decomposition c- Energy flow d- All are components of the ecosystem Earthworm is an example of a- Parasite b- Detrtivore c- Secondary consumer d- All are incorrect Some microbes degrade humus and release inorganic nutrients in the soil. This process is known as a- Mineralization b- Humification c- Fragmentation d- Leaching Assertion: Food web is natural interaction of the food chain. Reason: more stable food web represents a more stable ecosystem. a- Both assertion and reason are correct and the reason is the correct                explanation of assertion. b- Both assertion and reason are correct and the reason is not a correct      explanation of assertion. c- Assertion is true but the reason is false. d-Assertion is false but the reason is true.	4M
Q.9	Explain in detail the process of decomposition.	5M