Class 12 Biology - Chapter Ecosystem NCERT Solutions | What is the percentage of photosynthetic
What is the percentage of photosynthetically active radiation (PAR), in the incident solar radiation.
(a) 100%
(b) 50 %
(c) 1-5%
(d) 2-10%
(b) 50%
Out of total incident solar radiation, about fifty percent of it forms photosynthetically active radiation or PAR.
More Questions From Class 12 Biology - Chapter Ecosystem
- Q:- Give an account of energy flow in an ecosystem.
- Q:- Fill in the blanks.
(a) Plants are called as_________ because they fix carbon dioxide.
(b) In an ecosystem dominated by trees, the pyramid (of numbers) is _________ type.
(c) In aquatic ecosystems, the limiting factor for the productivity is _________.
(d) Common detritivores in our ecosystem are_________.
(e) The major reservoir of carbon on earth is_________. - Q:- Which one of the following has the largest population in a food chain?
(a) Producers
(b) Primary consumers
(c) Secondary consumers
(d) Decomposers - Q:- Distinguish between
(a) Grazing food chain and detritus food chain
(b) Production and decomposition
(c) Upright and inverted pyramid
(d) Food chain and Food web
(e) Litter and detritus
(f) Primary and secondary productivity - Q:- Define decomposition and describe the processes and products of decomposition.
- Q:-
Secondary producers are
(a) Herbivores
(b) Producers
(c) Carnivores
(d) None of the above - Q:- Describe the components of an ecosystem.
- Q:- Define ecological pyramids and describe with examples, pyramids of number and biomass.
- Q:- The second trophic level in a lake is-
(a) Phytoplankton
(b) Zooplankton
(c) Benthos
(d) Fishes - Q:- What is primary productivity? Give brief description of factors that affect primary productivity.
Popular Questions of Class 12 Biology
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- Q:-
Fill in the blanks:
(a) Humans reproduce __________. (asexually/sexually)
(b) Humans are__________. (oviparous/viviparous/ovoviviparous)
(c) Fertilization is __________ in humans. (external/internal)
(d) Male and female gametes are __________. (diploid/haploid)
(e) Zygote is __________. (diploid/haploid)
(f) The process of release of the ovum from a mature follicle is called__________.
(g) Ovulation is induced by a hormone called the __________.
(h) The fusion of male and female gametes is called _____________.
(i) Fertilisation takes place in _____________.
(j) Zygote divides to form _____________which is implanted in uterus.
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2 Comment(s) on this Question
50% of WHAT exactly? 50% of the photons? 50% of the energy content? Something else? This is a poorly thought out question. Try again.
Both hydrarch andxerarch lead to
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