Worksheets Class 12 Biology Ecosystem

Students should refer to Worksheets Class 12 Biology Ecosystem Chapter 14 provided below with important questions and answers. These important questions with solutions for Chapter 14 Ecosystem have been prepared by expert teachers for Class 12 Biology based on the expected pattern of questions in the class 12 exams. We have provided Worksheets for Class 12 Biology for all chapters on our website. You should carefully learn all the important examinations questions provided below as they will help you to get better marks in your class tests and exams.

Ecosystem Worksheets Class 12 Biology

Question. The components of ecosystem are seen to function as an unit, when we consider which of the folloiwng aspect
(a) Productivity and decomposition
(b) Decomposition and energy flow
(c) Productivity and energy flow
(d) Productivity, decomposition, energy flow and nutrient cycling

Question. Amount of biomass or organic matter produced per unit area over a time period by plants is represented or expressed in terms of :-
(a) Weight (g-2) – g-2 yr-1
(b) Energy (Kcal m-2) – Kcal m-2 / yr-1
(c) Fresh weight
(d) Dry weight

Question. In an aquatic ecosystem which type of food chain is major conduit for energy flow is
(a) GFC
(b) Parasitic food chain
(c) DFC
(d) Both 1 and 3

Question. The gradual and fairy predictable changes in the species composition of a given area is not characterised by :-
(a) Increase in number of species
(b) Increase in number of individuals of species
(c) Increase in biomass
(d) Decrease in niche specialisation

Question. About succession, which of the following statement is correct :-
(a) In xerosere, xeric conditions progress to hydric conditions
(b) In hydrosere, mesic environment progress to hydric conditions
(c) In hydrosere, hydric environment progress to mesic conditions
(d) Abandoned farm lands show primary succession

Question. During decomposition, humification leads to accumulation of a dark coloured amorphous substance called humus. Which of the following is correct regarding humus ?
(a) Susceptible to microbial action
(b) Undergoes decomposition at an extremely high rate
(c) Colloidal in nature
(d) It promote compaction of soil

Question. About flow of food energy by the process of eating and being eaten, which of the following is incorrect
(a) In an aquatic ecosystem, GFC is major conduit for energy flow
(b) In terrestrial ecosystem, DFC major conduit for energy flow
(c) In predator food chain there is increase in size  of organism with trophic level
(d) DFC can never be connected with GFC

Question. Mass of the living material at a particular time called as the standing crop. Biomass of a species is expressed in terms of …………. is more accurate
(a) Fresh weight
(b) Dry weight
(c) Both (a) and (b)
(d) Kcal m-2/yr-1

Question. In an ecosystem based on production of nearly 6 million plants, how many top consumers can be supported ?
(a) 708000
(b) 354000
(c) 3
(d) 30000

Question. In an ecosystem if dry weight of producers is 809 kgm-2. Then what will be the biomass of tertiary consumers
(a) 37 dry weight (Kg m-2)
(b) 11 (Kg m-2)
(c) 15 kg m-2
(d) 1.5 kgm-2

Question. Ecological pyramids show diagramatic representation of ecological parameters like number, biomass and energy. Which is / are limitation of ecological pyramids ?
(a) It does not take into account the same species belonging to two or more trophic levels
(b) It does not accomodate a food web
(c) Saprophytes are not given any place in pyramids
(d) All the above

Question. The gradual and fairly predictable changes in the species composition of a given area is called :-
(a) Bioprospecting
(b) Biofortification
(c) Ecological succession
(d) Ecological assessment

Question. All successions whether taking place in water or on land proceeds to which climax community :-
(a) Hydric
(b) Xeric
(c) Mesic
(d) Halophytic

Question. How much amount of carbon is fixed in biosphere through photosynthesis annually
(a) 2 x 10¹³ kg
(b) 4 x 10¹³ kg
(c) 5 x 10¹³ kg
(d) 6 x 10¹³ kg