1. The pyramid of numbers is inverted in case of
(a) parasitic food chain (b) grassland ecosystem (c) forest ecosystem (d) lake ecosystem.
2. Primary consumers are present at the______trophic level.
(a) First (b) Second
(c) Third (d) Fourth
3. In terrestrial ecosystem, we expect to see the biomass of the__________to be greater than the biomass of any other group of organisms.
(a) Producers (b) Primary consumers
(c) Secondary consumers (d) Top predators
4. Which of the following statements about ecological pyramids is true?
(a) Ecological pyramids are perfect with no limitations.
(b) Ecological pyramids show that carnivory is more efficient than herbivory.
(c) Ecological pyramids depict the total biomass of an ecosystem minus total energy used in respiration.
(d) Ecological pyramids demonstrate a 90% loss in energy at each step of the trophic level.
5. In an energy pyramid, which way does energy transfer take place?
(a) From top to the bottom of pyramid
(b) From bottom to the top of pyramid
(c) None of these
(d) Both of these
6. The pyramid of biomass is usually_________in pond ecosystem and_________in grassland ecosystem.
(a) spindle-shaped, upright
(b) upright, inverted
(c) inverted, upright (d) inverted, spindle-shaped
7. Which of the following statements is incorrect regarding ecological pyramids?
(a) The pyramid of energy is inverted in ocean ecosystem.
(b) The pyramid of biomass is inverted in aquatic ecosystem.
(c) The pyramid of numbers is upright in grassland ecosystem.
(d) The pyramid of numbers is spindle shaped in forest ecosystem.
8. The trophic structure of an ecosystem can be represented as a pyramid of
(a) numbers (b) biomass
(c) energy (d) all of these.
9. The concept of ecological pyramids was first proposed by
(a) E.P. Odum (b) A.G.Tansley
(c) Juday (d) Charles Elton.
10. Which of the following ecological pyramids is the most fundamental?
(a) Pyramid of numbers (b) Pyramid of biomass (c) Pyramid of energy (d) Both (b) and (c)
1. Which of the following is a primary consumer in maize field ecosystem?
(a) Grasshopper (b) Wolf
(c) Phytoplankton (d) Lion
2. The upright pyramid of number is absent in
(a) pond (b) forest
(c) lake (d) grassland.
(AIPMT Prelims 2012)
3. Which one of the following animals may occupy more than one trophic levels in the same ecosystem at the same time?
(a) Sparrow (b) Lion
(c) Goat (d) Frog
(AIPMT Mains 2011)
4. Which of the following is true in case of pond ecosystem?
(a) Pyramid of energy is always upright.
(b) Pyramid of energy is always inverted.
(c) Pyramid of biomass is always upright.
(d) None of these. (Odisha 2012)
5. An inverted pyramid of number and an inverted pyramid of biomass are respectively seen in
(a) grassland and tree ecosystem
(b) sea and tree ecosystem
(c) tree and sea ecosystem
(d) sea and grassland ecosystem
(e) tree and grassland ecosystem. (Kerala 2012)
6. Which one of the following statements for the pyramid of energy is incorrect ?
(a) Its base is broad
(b) It shows energy content of different trophic level organisms
(c) It is inverted in shape
(d) It is upright in shape
(AIPMT Prelims 2011)
7. Which of the following representations shows the pyramid of numbers in a forest ecosystem?
(a) D (b) A
(c) B (d) C (AIPMT Mains 2010)
8. When man eats fish which feeds on zooplanktons which have eaten small plants, the producer in this chain is
(a) small plants (b) fish
(c) man (d) zooplankton.
9. In a food chain, the total amount of living material, is depicted by
(a) pyramid of biomass (b) pyramid of energy (c) pyramid of numbers (d) all of the above.
10. What percentage of energy is transferred from one trophic level to another ?
(a) 10% (b) 1%
(c) 0.1% (d) 0.01%. (AMU 2005)
The following questions consist of two statements each : assertion (A) and reason (R).To answer these questions, mark the correct alternative as directed below:
(a) If both A and R are true and R is the correct explanation of A.
(b) If both A and R are true but R is not the correct explanation of A.
(c) If A is true but R is false.
(d) If both A and R are false.
Part – III
1. Assertion (A): The amount of energy decreases from the producer level to the consumer level in a food chain. Reason (R): At each trophic level, 80 – 90% of energy is lost.
2. Assertion (A) : The pyramids of number, biomass and energy are always upright.
Reason (R): Producers always outnumber and outweigh the herbivores which in turn always outnumber and outweigh the carnivores.
3. Assertion (A): A given species may occupy more than one trophic level in the same ecosystem at the same time. Reason (R): Pyramid of numbers is inverted in a parasitic food chain.
4. Assertion (A): Pyramid of numbers in pond ecosystem is upright.
Reason (R): The number of organisms in a pond ecosystem decreases from phytoplankton to zooplankton and further to fishes.
5. Assertion (A): In forest ecosystem, flow of energy is unidirectional.
Reason (R) : In a forest, the biomass of trees is the maximum and the biomass of top consumers is the minimum.
Part – IV
1. Pyramid of energy is considered as the most fundamental pyramid. Explain.
2. Briefly describe the pyramid of numbers in a pond ecosystem.
3. Discuss the advantages of pyramid of energy.
4. Why is pyramid of biomass inverted in an open water system?
5. Why there are no predators that feed on tigers?
1. (a) 2. (b) 3. (a) 4. (d) 5. (b)
6. (c) 7. (a) 8. (d) 9. (d) 10. (c)
1. (a) 2. (b) 3. (a) 4. (a) 5. (c)
6. (c) 7. (d) 8. (a) 9. (a) 10. (a)
1. (a) 2. (d) 3. (b) 4. (a) 5. (b)
Part – IV
1. Of the three types of ecological pyramids, the energy pyramids are the most fundamental. Here, number and weight of organisms at any level depends not on the amount of fixed energy present at any time but on the rate at which food is being produced. In contrast with the pyramids of number and biomass, which depict the standing situations (organisms present at any moment), the pyramid of energy shows the transfer of energy through the food chain. In shape it is always upright, as in most of the cases there is always a gradual decrease in the energy content at successive trophic levels from the producers to various consumers.
2. Pond ecosystem has an upright pyramid of numbers. Here the producers which are mainly the phytoplanktons (algae, bacteria, etc.) are maximum in number; the herbivores (smaller fish, rotifers, etc.) are lesser in number than the producers. The secondary consumers /.&, carnivores (small fish, water beetles, etc.) are further lesser in number than the herbivores and finally, the top (tertiary) consumers (the bigger fish) are least in number.
3. The advantages of pyramid of energy are given below:
(i) It is highly informative as it gives precise data regarding the amount of energy required to support a trophic level in an ecosystem.
(ii) Pyramid of energy is based upon productivity instead of standing crop.
(iii) It allows comparison amongst different ecosystems and different populations of the same ecosystem.
4. In open water or deep water situations where producers are small and short-lived, the standing crop situation at any one moment may be widely variable. Also standing crop will likely be smaller than that of land or shallow water communities, even if the total energy fixed annually is the same. Thus, the pyramid of biomass in such situations is inverted.
5. In terrestrial ecosystem, tiger occupies the highest consumer level. During energy flow through trophic levels, available useful energy decreases as one moves from one trophic level to other. At tiger’s trophic level, there is not enough energy left to support still higher trophic level.