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Free Download as PDF of the detailed solutions for class 12 Biology from NCERT or CBSE text book as per exam pattern, to help you in day to day learning. We provide all important questions and answers from chapter Organisms and Populations of Biology.
(16)
In a population, if the rate of addition of new members is higher than the rate of individuals lost, it shows
[1]
Exponential growth
[2]
Declined growth
[3]
Zero population growth
[4]
none of these
Answer: Exponential growth
(17)
Animals that have adapted themselves to live in deserts are known as
[1]
Fossorial
[2]
Xerocoles
[3]
Arboreal
[4]
Terrestrial
(18)
Which of the followings take part in symbiosis of lichen?
[1]
Fungus-Fungus
[2]
Alga-Alga
[3]
Alga-Fungus
[4]
Fungus-Gymnosperm
(19)
Ultraviolet radiation which is not lethal but harm to the organism is
[1]
0.1 to 0.28 µm
[2]
0.28-0.32 µm
[3]
0.32-0.4 µm
[4]
0.4-0.5 µm
(20)
In an ecosystem Biotic factors affect the survival of an organism in that ecosystem. They include
[1]
competition for food and water
[2]
competition for shelter
[3]
co-operation to help find food
[4]
All of these
21
Association between sea Anemone and Hermit crab in gastropod shell is that of
[1]
Parasitism
[2]
Commensalism
[3]
Symbiosis
[4]
Amensalism
22
Plant succession occurring in a sandy area is
[1]
Xerosere
[2]
Halosere
[3]
Psammosere
[4]
Hydrosere
23
Which one of the following is categorized as a parasite in true sense?
[1]
The cuckoo lays its egg in crow's nest
[2]
The female Anopheles bites and sucks blood from humans
[3]
Human foetus developing inside the uterus draws nourishment from the mother
[4]
Head louse living on the human scalp as well as laying eggs on human hair
Answer: Head louse living on the human scalp as well as laying eggs on human hair
24
Ecological niche of an organism represents
[1]
The resource it utilizes
[2]
Functional role in the ecological system
[3]
The range of conditions that it can tolerate
[4]
all of these
25
Respiratory roots are known as
[1]
velamen
[2]
pneumatophores
[3]
hydathodes
[4]
prop roots
26
The maximum amount of water that a soil can hold, by capillary action is called
[1]
Wilting point
[2]
Water potential
[3]
Field capacity
[4]
Osmotic potential
27
A population with equal number of births and deaths will show
[1]
Acceleration phase of growth
[2]
Plateau phase
[3]
Exponential growth phase
[4]
Initial phase of growth
28
Biotic potential is increase in population under
[1]
Optimum conditions
[2]
Climatic conditions
[3]
Natural conditions
[4]
Given conditions
Answer: Optimum conditions
29
In ecological succession from pioneer to climax community, the biomass shell
[1]
No relation
[2]
Increase and then decrease
[3]
Decrease
[4]
Increase continuously
Answer: Increase continuously
30
. The gradual physiological adjustment to slowly
changing new environmental conditions is known as
[1]
Selection
[2]
Introduction
[3]
Acclimatization
[4]
Quarantine
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