1. The transitional zone between two adjacent communities is
a. Ecotype
b. Ecoline
c. Ecotone
d. Ecozone
Correct answer: c, Ecotone is the transitional zone between two
adjacent communities. It is where two biomes meet and integrate.
2. Which of the following statements is correct regarding pyramid of
biomass of pond ecosystem?
a. Biomass of
consumer is greater than biomass of producer
b. Biomass of
producers is greater than biomass of consumer
c. Large
carnivores’ fishes are primary consumers
d. Biomass of
producer is equal to biomass of consumer
Correct answer: a, In pond ecosystem, biomass of consumers is greater
than biomass of producers. Such a pyramid is inverted.
3. Gaseous exchange between animals and atmosphere is negligible in
a. Carbon cycle
b. Phosphorous
cycle
c. Oxygen cycle
d. Carbon and
phosphorous cycles
Correct answer: b, In phosphorous cycle, gaseous exchange between
organism and atmosphere is negligible. There is no respiratory release of
phosphorous in the atmosphere.
4. Biological maintenance of a constant internal environment is
called
a. Adaptability
b. Thermal
conversion
c. Homeostasis
d. Ecological
efficiency
Correct answer: c, Homeostasis is the maintenance of a constant
internal environment in response to environmental changes.
5. According to Raunkiaer (1934), the plants whose buds occur
very deep in the soil are
a. Therophytes
b. Cryophytes
c. Hemicryophytes
d. Chemaephytes
Correct answer: b, Cryptophytes are the plants whose buds occur very
deep in the soil e.g. bulbs, rhizomes, corm, tubers etc.
6. Rocks of the Earth's crust are a major contributor to the
a. Calcium cycle
b. Oxygen cycle
c. Carbon cycle
d. Nitrogen cycle
Correct answer: c, Rocks of the Earth's crust contain carbonates and
are major contributors of carbon to the carbon cycle.
7. Pioneer stage of succession in xerosere always begins with
a. Thin soil on
rock
b. Xeric rock
c. Thick layer of
soil on rock
d. Water bed
Correct answer: b, Primary stage of succession in xerosere develops on
extremely xeric rock. Here, the water and nutrients are extremely scarce and
conditions are hostile by exposure to the sun and temperature.
8. Submerged state of succession in water is characterised by the
presence of
a. Carex
b. Typha
c. Trapa
d. Utricularia
Correct answer: d, Submerged state of succession in water is
characterised by the presence of utricularia. Utricularia is a submerged
aquatic plant and on death adds organic matter to the bottom.
9. Grazing food chain (GFC) is a major conduit for energy flow in
a. Desert
ecosystem
b. Terrestrial
ecosystem
c. Aquatic
ecosystem
d. Both desert
and terrestrial ecosystem
Correct answer: c, Grazing food chain is a major conduit for energy
flow in aquatic ecosystem.
10. Rate of decomposition is slower if detritus is rich in which of
the following?
a. Lignin
b. Nitrogen
c. Chitin
d. Sugars
a. b and d
b. a and c
c. a and b
d. c and d
Correct answer: b, Rate of decomposition is
slow if the soil is rich in lignin and chitin.
11. In a grassland ecosystem, the tropic level equivalent of birds in
tree ecosystem is of
a. Grasshopper
b. Frogs
c. Snakes
d. Eagle
Correct answer: a, Tropic level of grasshopper in grassland ecosystem
is T2, which is the same as tropic level of birds in a tree ecosystem.
12. Primary productivity depends upon which of the following factors?
a. Flora of a particular area
b. Fauna of a particular area
c. Environment of a particular area
a. Only a
b. Only b
c. Both a and b
d. Both a and c
Correct answer: d, Primary productivity depends upon plant species
(flora) inhabiting a particular area. It also depends upon several
environmental factors like availability of nutrients and photosynthetic
capability of the plants.
13. Pyramid of number in a parasitic food chain is always
a. Upright
b. Inverted
c. Either upright
or inverted
d. Partly upright
Correct answer: b, Inverted pyramid of number is seen in a parasitic
food chain (where one primary producer supports numerous parasites) as it
supports more hyperparasites.
14. Net primary productivity takes which of the following into
consideration?
a. Biomass of
primary producers left over by consumers
b. Resynthesis of
energy yielding substrates
c. Loss due to
respiration
d. Energy trapped
by photosynthesis
Correct answer: c, Net primary productivity considers losses due to
respiration and decomposition. It is given by gross productivity minus losses
due to production.
15. Which of the following ecosystems has the least amount of
decomposers?
a. Pond ecosystem
b. Forest
ecosystem
c. Agro ecosystem
d. Desert
ecosystem
Correct answer: d, There are very few decomposers in a desert
ecosystem. Due to poor vegetation, the amount of dead organic matter is
correspondingly less. There are some fungi and bacteria in a desert ecosystem
most of which are thermophilic
16. In case of pond ecosystem, in which of the following zones is it
expected to see miscellany of plants along with zooplanktons?
a. Littoral
b. Limnetic
c. Profoundal
d. Both a and b
Correct answer: b, Limnetic zone is the region of open water, where
light can reach. This zone contains miscellany of plants and zooplanktons.
17. Which of the following statements are true for certain plants
classified as heliophytes?
a. They have coarse tiny leaves with hairy and waxy protection.
b. They have larger photosynthetic units than sciophytes.
c. Chloroplasts have a protective element such as carotenoid.
d. Polytrichum
commune is a typical
example.
a. a and d
b. b and d
c. a and c
d. b and c
Correct answer: c, Heliophytes have coarse tiny leaves with hairy and
waxy protection against excessive light radiation and water loss. Their
chloroplasts have a protective element, such as carotenoid and enzymes.
18. Which of the following characteristics can be attributed to
Poikilothermal animals?
a. They undergo aestivation during summers.
b. They undergo hibernation during winters.
c. Their body is generally covered with hair.
d. They generally have constant body temperature.
a. b and d
b. a and c
c. c and d
d. a and b
Correct answer: d, Poikilotherms hibernate in winters to prevent
themselves from cold and undergo aestivation during summers to prevent
themselves from high temperature.
19. Vines, maple and spring flowers are common in an ecosystem where
a. Rainfall
ranges from 10-35 cm
b. Rainfall is
below 25 cm
c. Rainfall
ranges from 75 to 100 cm
d. Rainfall is
greater than 140 cm
Correct answer: a, Vines, maple and spring flowers are common in Taiga
forests where rainfall ranges from 10 to 35 cm.
20. Benthos with respect to pond ecosystem are
a. Primary
consumers in the water surface
b. Primary
consumers under the water surface
c. Secondary
consumers under the water surface
d. Decomposers on
floor of pond
Correct answer: b, Primary consumers which are found under the surface
of water are called as benthos, such as many type of fishes, crustaceans,
molluscs, insects, beetles, etc. They too feed on producers.
21. Primary consumers are in greater number than producers in
a. Pyramid of
number of pond ecosystem
b. Pyramid of
number of grassland ecosystem
c. Pyramid of
number of tree ecosystem
d. Pyramid of
number of both pond and tree ecosystems
Correct answer: c, In pyramid of tree ecosystem, consumers are in
greater number than producers. Thus, inverted pyramid of number is obtained.
22. In pyramid of number of forest ecosystem,
a. Number of
producers is more than number of herbivores
b. Number of
carnivores is more than number of herbivores
c. Number of
herbivores is more than number of carnivores
d. Number of
producers is more than number of carnivores
Correct answer: c, In pyramid of number of forest ecosystem, number of
herbivores is more than number of carnivores. Partly upright pyramid of number
is obtained for forest ecosystem.
23. Choose the correct alternative from the following:
Assertion (A): Phosphorous cycle is the slowest
biogeochemical cycle.
Reason (R): Phosphates move quickly through plants
and animals.
a. Both A and R
is true and R is the correct explanation of A
b. Both A and R
is true but R is not the correct explanation of A
c. A is true but
R is false
d. A is false but
R is true
Correct Answer: b, Both A and R are true but R is not the correct
explanation of A. Phosphorous cycle is the slowest biogeochemical cycle because
the processes that move phosphates through the soil or ocean are very slow and
decomposers take a longer time to decompose any dead biota into phosphates.
24. In lithosere, the first stage commences with the dominance of
which of the following organisms?
a. Lecidia, Rinodina and
Graphis
b. Dermatocarpon, Parmelia and
Physcia
c. Torula, Grimmia and Bryum
d. Poa, Tridax and Festuca
Correct
answer: a, The first stage that commences in lithosere is with the dominance of Lecidia,
Rinodina and Graphis. This is called the crustose lichen stage and is marked by
conditions aggravated by exposure to the Sun, wind, and extreme temperature.
25. Amount of CO2 fixed
by a gram of chlorophyll in an hour is a measure of
a. Net primary
productivity
b. Gross primary
productivity
c. Net community
productivity
d. Secondary
productivity
Correct answer: Gross primary productivity is measured in terms of
assimilation number or photosynthetic number, i.e. amount of CO2 fixed by a gram of chlorophyll in an
hour.
26. Which of the following organisms is not a nitrogen fixer?
a. Rhizobium
b. Aulosina
c. Pseudomonas
d. Clostridium
Correct answer: Pseudomonas is a bacterium that helps in the denitrification process. It reduces nitrates to molecular nitrogen.
27. Which of the following is true about the biogeochemical cycle?
a. Smaller
biological water cycle is found in aquatic ecosystems
b. Nitrogen
returns to the soil after the death of organism in form of nitrates
c. Volcanic
activities add phosphorous into the atmosphere
d. Clostridium
reduces the sulfur under anaerobic conditions
Correct answer: a, Smaller biological water cycle comprises environmental water into the living system and its return. Aquatic animals absorb
water from their surroundings and excrete it. After the death of organisms,
water returns to the surrounding medium through the process of decay. Like
this, a smaller biological water cycle is found in aquatic ecosystems.
28.
likely organisms A, B, C and D, respectively in the food web given above are
a. Monkey,
lizard, earthworm, deer
b. Deer, snake,
earthworm, eagle
c. Squirrel, fox,
earthworm, deer
d. Squirrel,
snake, grasshopper, deer
Correct answer: d, A is squirrel as squirrel eats fungus and is eaten
by hawk; B is snake as snake eats shrew and is eaten by hawk or mountain lion;
C is grasshopper as grasshopper eats grass and is eaten by shrew or insect
eating bird; D is deer as deer eats plants and shrubs and is eaten by mountain
lion.
29. A parasitic food chain starts with
a. Parasite
b. Herbivore or
producer
c. Saprophyte
d. Dead organic
matter
Correct answer: b, Parasitic food chain starts with herbivore which
passes the energy to parasites. In this type of food chain, either the producer
or the consumer is parasitised and therefore, the food passes to the smaller
organism. The energy transfer through this kind of food chain is not
significant.
Producer
Herbivore Parasite Hyperparasite
30. The minimum requirement for an ecosystem to survive is
a. Primary and
secondary consumers
b. Producers and
primary consumers
c. Producers and
decomposers
d. Consumers and decomposers
Correct answer: c, The minimum requirement for an ecosystem to survive
is producers and decomposers. Decomposers are essential for recycling of
materials and thereby providing nutrients for the producers. All heterotrophs
in the food web ultimately depend upon producers for their food.
31. The association between a barnacle and a blue whale can be rightly
said as:
a. Ammensalism
b. Mutualism
c. Predation
d. Commensalism
Correct answer: d, The symbiotic relationship between a barnacle and a
whale is known as commensalism, which describes an inter-species interaction
that benefits at least one participant. Whales do not gain a significant
benefit from the presence of barnacles on their bodies. However, their presence
is not especially damaging or harmful to the whales either. Barnacles, on the
other hand, gain a tremendous advantage from their partnership with whales. By
attaching themselves to the belly, back and sides of whales, they enable themselves
to hitch a free ride through nutrient-rich water environments. This allows
barnacles to consume micro-organisms that float freely in the water, which
would otherwise be inaccessible to the barnacles.
32. In a relationship between prickly pear and moth,
a. Moth is harmed
b. Prickly pear
is harmed
c. Prickly pear
is benefitted
d. Both prickly
pear and moth are benefitted
Correct answer: b, Moth threatens the population of prickly pear; thus
prickly pear is harmed. Moth is used as a biological control agent for prickly
pear.
33. Production and storage of toxin to keep away predators is used by:
a. Opuntia
b. Acacia
c. Calotropis
d. Papavar
Correct answer: c, Calotropis produces and stores a toxin to keep away
the predators. Cattle often stay away from the plants because of their
unpleasant taste and their content of cardiac glycosides.
34. Camouflage for defence to lessen the impact of predation is
observed in
a. Fungi and
Algae
b. Monarch
butterflies and dead butterflies
c. Frogs and
monarch butterflies
d. Frogs and
insects
Correct answer: d, Frogs and most of the insects camouflage to lessen
the impact of predation.
35. Allen's rule is visible in which of the following organisms?
a. Kangaroo rats
b. Desert lizards
c. Polar bears
d. Desert plants
Correct answer: c, According to Allen's rule, cold climate mammals
have short ears and limbs to minimise heat loss. This is visible in polar
bears. Polar bear is a cold climate mammal which has short ears and limbs.
36. Spontaneous reduction in development process and metabolism to
deal with the stressful condition is observed in:
a. Zooplankton
b. Polar bears
c. Snails
d. Seeds
Correct answer: a, To deal with stressful situations diapause, i.e.
spontaneous reduction in development process and metabolism is observed in
zooplankton.
37. Salmon and coral reefs respectively are
a. Thermophilic
and Cryophilic
b. Cryophilic and
Thermophilic
c. Stenothermal and
eurythermal
d. Both are eurythermal organisms
Correct
answer: b, Salmon
are cryophilic, i.e. they thrive at low temperature; whereas coral reefs are
thermophilic, i.e. they thrive at high temperature.
38. Mortality is the number of deaths in an area
a. To the number
of births in an area
b. Per unit area
c. Per 1000
individuals
d. To the total
population of the area
Correct answer: d, Mortality is the ratio of the number of deaths in
an area to the total population of the area. It is expressed as the loss of
individuals with respect to the members of the population.
39. A population pyramid with extremely low percentage of younger
population reflects
a. High death
rate and high birth rate
b. Low death rate
and high life expectancy
c. Low death rate
and low birth rate
d. High birth
rate and low life expectancy
Correct answer: c, A population pyramid with extremely low percentage
of younger population reflects low death rate and low birth rate. Such pyramids
are constrictive pyramids. It is typical for a highly developed country.
40. Least concentration of clay is seen in
a. Clayey soil
b. Sandy-loam
soil
c. Clay-loam soil
d. Silt-loam soil
Correct answer: b, Sandy-loam soil has 20% clay.
41. Water which is available and absorbed by the plants exists as
a. Water between
soil particles
b. Water in
chemical compounds
c. Water at water
table
d. Water tightly
held by soil particles
Correct answer: a, Water that exists between soil particles in small
capillary pores is called capillary water. This water is available to plants
and readily absorbed by them.
42. The maximum birth rate that a species can achieve under ideal
environmental conditions is:
a. Realized
natality
b. Potential
natality
c. Population
density
d. Ecological
density
Correct answer: b, The maximum birth rate that
a species can achieve under ideal environmental conditions is potential
natality.
43. In a J-shaped growth curve, the lag phase signifies
a. Period of slow
rise in population due to environmental conditions
b. Rapid rise in
population due to plenty of food available
c. Period of
adaptation
d. Period of
stable growth
Correct answer: c, Lag phase in a J-shaped curve is a period of
adaptation of animals to new environment, so it is characterized by slow or no
growth in population.
44. Which of the following statements is true with respect to
Verhulst-Pearl logistic growth?
a. Population
grows in habitat having limited resources
b. Population
grows in a habitat having copious resources
c. Carrying
capacity is never achieved
d. J-shaped curve
is obtained
Correct answer: a, According to Verhulst-Pearl logistic growth, a
population grows in a habitat which has limited resources. In exponential or
geometric growth curve, population grows in a habitat having unlimited
resources.
45. Which of the following statements are correct?
a. Oysters produce a small number of large sized offspring.
b. Bamboo breed only once in lifetime.
c. In both predation and parasitism, only one species is benefited.
a. a and c
b. a and b
c. b and c
d. a, b and c
Correct answer: c, This is the correct answer as both statements b and
c are true.
46. The maximum population size of a species that an environment can sustain
indefinitely is known as which of the following?
a. Field capacity
b. Carrying
capacity
c. Reproductive
success
d. Age specific
rate
Correct answer: b, Carrying capacity of a biological species in an
environment is the maximum population size of the species that the environment
can sustain indefinitely, given that it has all it needs for survival.
47. Stenothermal organisms can survive in a
a. Broad range of
temperature
b. Narrow range
of temperature
c. Wide range of
salinity
d. Narrow range
of salinity
Correct answer: b, Stenothermal organisms can tolerate and thrive in a
narrow range of temperature.
48. Choose the correct alternative from the following.
Assertion (A): Small animals lose their body heat
fast.
Reason (R): Small animals have small
surface/volume ratio.
a. Both A and R
are true and R is the correct explanation of A
b. Both A and R
is true but R is not the correct explanation of A
c. A is true but
R is false
d. A is false but
R is true
Correct answer: c, A is true but R is false. Small animals lose their
body heat very fast but they do not have a small surface/volume ratio. In fact,
small animals have large surface/volume ratio
49. 'Suspend' is one of the ways by which organisms
deal with stressful conditions. Match the organism with the way it undertakes
to cope with stressful conditions.
|
Method to suspend |
Organism |
|
1. Dormancy |
a. Zooplankton |
|
2. Hibernation |
b. Seed |
|
3. Aestivation |
c. Bear |
|
4. Diapause |
d. Snail |
a. 1 - b, 2 - c, 3 - d, 4 – a
b. 1 - b, 2 - a, 3 - d, 4 – c
c. 1 - b, 2 - d, 3 - c, 4 – a
d. 1 - b, 2 - c, 3 - a, 4 – d
Correct
answer: a, Seeds
go into a dormant state to cope with stressful conditions. They germinate under
favorable conditions.
Bears undergo hibernation to cope with extreme cold conditions.
Snails undergo aestivation to avoid summer related problems.
Zooplanktons enter diapause, a state of suspended development.
50. Which of the following pairs is incorrect?
a. Breed many times in a
lifetime - Birds and mammals
b. Breed once in a lifetime -
Pacific salmon fish
c. Produce small sized but large
number of offspring – Oysters
d. Produce large sized but small
number of offspring - Pelagic fishes
Correct
answer: d, This
is an incorrect pair. Pelagic fishes produce small sized but large number of
offspring.
51. Which of the following factors have a positive effect on
population density?
a. Immigration
b. Emigration
c. Natality
d. Mortality
a. Only b and d
b. Only a and d
c. Only a and c
d. Only b and c
Correct answer: c, A positive effect on population density is caused
by immigration and natality. Both help in increasing the population.
52. Tight one to one relationship is observed between fig and female
wasp. The female wasp uses the fig tree for which of the following?
a. Egg laying
b. Obtaining food for itself
c. Nourishment for larvae
d. Obtaining nectar
a. Only a and d
b. Only a and b
c. Only a and c
d. Only b and c
Correct answer: c, Female wasp uses fig fruits for oviposition (egg
laying). It also uses the developing fruits within the larvae for nourishing
its larvae.
53. Which of the following associations shows the same relationship as
an orchid and mango branch?
a. Flamingo and
Fish
b. Cow and Cuckoo
c. Plant root and
fungus
d. Cattle and
egret
Correct answer: d, The relationship between cattle and egret shows
commensalism interaction. Similarly, orchids show commensal interaction with
mango branch. Orchids get support of the mango plant, while mango plant does
not get any benefit. Similarly, egrets always forge where cattle are grazing
and eat insects flushed out by cattle from the vegetation. However, cattle
achieve no benefit from egrets.
54. Balanus dominatus of rocky sea coasts of Scotland excluded the
smaller Barnacle Chathamalus from the intertidal area. State the relationship
mentioned in this sentence?
a. Parasitism
b. Predation
c. Competitive
release
d. Emigration
Correct answer: c, Balanus dominatus of rocky sea coasts of Scotland excluded the smaller Barnacle
Chathamalus from the intertidal area. This relation is competitive release
(restriction of a species to a small geographical area because of presence of a
competitively superior species).
55. Which of the following options is true according to Allen's rule?
a. Animals living
in cold climate have shorter ears and longer limbs
b. Animals living
in cold climate have shorter ears and shorter limbs
c. Animals living
in cold climate have longer ears and shorter limbs
d. Aquatic
animals in polar region have blubbers under their skin
Correct answer: b, According to Allen's rule, animals living in cold
climate have shorter ears and limbs to prevent heat loss.
56. How does female anopheles mosquito benefit from its host?
a. Female anopheles mosquito
needs fats from the host for making its eggs.
b. Female anopheles mosquito takes
food from the host.
c. Female anopheles mosquito needs
blood of host for making eggs
d. Female anopheles
mosquito needs blood of host for making eggs and obtains food from the host
Correct answer: c, Female anopheles mosquito
needs the host's blood for making eggs. Its eggs require iron, which it derives
from the blood.
57. A population pyramid with a narrow base does not tend to have low
a. Life
expectancy
b. Death rate
c. Birth rate
d. Younger
population
Correct answer: a, A population pyramid with a wide base (expansive
pyramid) is of population with low life expectancy
58. Which of the following statements is/are correct?
1. Aquatic organisms never face any problem from water.
2. Geographical distribution is dependent upon level of thermal tolerance of
different species.
3. Sunlight is insignificant for animals who are dependent on plants for food.
a. Only 1 and 3
b. Only 1 and 2
c. Only 2
d. Only 2 and 3
Correct answer: Statement 1 is false as aquatic organisms are
influenced by the pH of water. Different organisms can tolerate different salt
concentrations.
Statement 2 is true as geographical distribution is dependent upon level of
thermal tolerance of different species. Some animals can tolerate high
temperatures whereas optimum temperature for others is different.
Statement 3 is false as sunlight plays a significant role in the life of
animals that are dependent on plants for food. Animals use diurnal and seasonal
variations in light intensity and duration as hints for foraging, reproductive
and migratory activities.
59. A large naturally occurring community of flora and fauna
occupying a major habitat constitutes
a. Population
b. Biome
c. Community
d. Ecosystem
Correct answer: A large naturally occurring community of flora and
fauna occupying a major habitat constitutes biome
59. Which of the following animals in North American desert has the
capability to meet all its water requirements through internal oxidation of
fats?
a. Kangaroo rat
B.Wool rat
c. Horned lizard
d.Desert tortoise
Correct answer: a, Kangaroo rat in North American desert has the
capability to meet all its water requirements through internal oxidation of
fats. This enables the kangaroo rat to survive for months without water.
60.
Odum
defined ecology as the branch of science which deals with the study of
a. Relationship
between things and environment
b. Structure and
function of nature
c. Interaction
between species
d. Ecological importance
of the environment
Correct answer: b, According to Odum (1965), ecology is the branch of
science which deals with the study of structure and functions of nature.
61. Occurrence of more than two type of leaves in a plant is called
heterophylly. Heterophylly is found in
a. Eichhornia
b. Nymphaea
c. Sagittaria
d. Vallisneria
Correct answer: c, Occurrence of more than two types of leaves in a
plant is called heterophylly. It is seen in sagittaria. It bear leaves of many
types namely submerged leaves, floating leaves, aerial leaves etc.
62. If the survivor-ship curve of organism X is straight, then X most
probably is:
a. Birds
b. Fishes
c. Large mammals
d. Hydra
Correct answer: d, Survivor-ship curve is straight (type II) for
hydra. Individuals with straight curve have a death rate that is relatively
constant at any age. X is hydra.
63.
Grasses like Cynodon dactylon are
exploited in method X of soil conversion. Which of the following is method X?
a. Strip cropping
b. Mulching
c. Lay farming
d. Dry farming
Correct answer: c, Lay farming aims to grow grasses Cynadon dactylon in rotation with the field crops,
which helps in binding the structure of the soil, preventing soil erosion and
improving its fertility.
64. Supporting services of an ecosystem include
a. Food products
b. Water
recycling
c. Cultural
heritage
d. Pest
regulation
Correct answer: b, Water recycling is included in the supporting
services. Supporting services include those ecosystem services which are
necessary for the production of all other ecosystem services, such as soil
formation, primary production, water cycling, nutrient cycling, etc
65. Upright and inverted pyramids, respectively, are obtained for
a. pyramid of energy of
grassland ecosystem and pyramid of number of grassland ecosystem
b. pyramid of biomass of tree
ecosystem and pyramid of number of tree ecosystem
c. pyramid of
biomass of pond ecosystem and pyramid of number of pond ecosystem
d.
pyramid of
number of grassland ecosystem and pyramid of number of pond ecosystem
Correct
answer: b, Pyramid
of biomass of tree ecosystem is upright, whereas pyramid of number of tree
ecosystem is inverted.
66. Apropos to hydrophytic adaptations, which of the following
sentences is true?
a. Vascular tissue is more
developed in submerged form as compared to in floating form
b. Leaves of amphibian plants show
mesophytic characters.
c. Submerged plants are cutinized
d. Mechanical tissues are present in
the submerged plants to give mechanical support
Correct
answer: b, Mesophytes
are terrestrial plants which are adapted to neither a particularly dry nor a
particularly wet environment. The amphibious plants are marshy plants, the
leaves that are exposed to air show typical mesophytic features. They are
leathery and tougher than the submerged and floating hydrophytes.
67. Australian acacia is adapted to desert climate. An adaptation seen
in its leaves is
a. Reduction of
leaves to the spines
b. Flattening of
petiole
c. Upward rolling
of leaves
d. Modification
of stipules into spines
Correct answer: b, In Australian acacia, petiole becomes flattened, green,
leaf-like and does the work of normal lamina. This modified structure is called
phyllode
68. Which of the following statements is suitable for euhydatophytes?
a. Reproductive
portions are submerged
b. Vegetative
portions are submerged
c. Whole plant is
submerged
d. These plants
can live on both land and water
Correct answer: b, Euhydatophytes are those aquatic plants whose
vegetative portions are submerged.
69. Obligate heliophytes are the plants which
a. Can bear shade
b. Can tolerate
high light intensity
c. Cannot bear
shade
d. Cannot
tolerate high light intensity.
Correct answer: Heliophytes that cannot bear shade are termed as
obligate heliophytes.
70. Insects like mayflies, dragonflies and stone-flies are
characterized by
a. Incomplete
metamorphosis
b. Complete
metamorphosis
c. Gradual
metamorphosis
d. No
metamorphosis
Correct answer: a, Mayflies, dragonflies and stone-flies are
characterized by incomplete metamorphosis. The adult insect with incomplete
metamorphosis lays its eggs in or near water and the naiads develop in water.
The adults are flying insects that live out of water. Naiads and adults,
therefore, do not eat the same kind of food. Naiads have chewing mouth parts,
but the adults have differently shaped chewing mouth parts or no functional
mouth parts. The naiad and the adult usually differ a lot in appearance,
although the naiads gradually develop wings
71. Anthoceros is a genus of hornworts. Hornworts obtain N2by
symbiotic relationship with
a. Azolla
b. Nostoc
c. Calothrix
d. Oscillatoria
Correct answer: b, Anthoceros species are host to species of Nostoc, a
symbiotic relationship in which Nostoc provides nitrogen to its host through
cells known as heterocysts
72. The reed-swamp stage of hydrosere is dominated by
a. Elodea, Vallisneria and
Urticularia
b. Pistia, Trapa and Lemna
c. Rumex, Typha and
Scripus
d.
Carex,
Cyperus and Juncus
Correct
answer: c, Rumex,
Typha and Scripus dominate the reed-swamp stage of hydrosere. This stage is
also known as the amphibious stage. The plants have well developed rhizomes and
form very dense vegetation. The water level is by now very much reduced and
finally becomes unsuitable for these plants
73. Constructive pyramid is obtained for a country which has
a. Low death
rate, low birth rate
b. High death
rate, high birth rate
c. Short life
expectancy
d. Poor health
care facilities
Correct answer: a, Constructive pyramid is obtained for a country
which has low death rate but also low birth rate; and a few or no negative
environmental factors
a. They show normal growth and internodes are elongated.
b. Chlorophylls are lacking in epidermal cells.
c. Stomata are present in equal numbers on both surfaces of leaf.
d. Stomata are sunken.
a. a and b
b. a and c
c. b and d
d. b and c
Correct answer: b, In Scotophilous plants shoots grow normally and
internodes are elongated. Stomata are in equal numbers present on both the
surfaces of leaf.
75. Plant species on the verge of extinction due to excessive
quarrying in Kerala is
a. Podophyllum
b. Dipcadi
montanum
c. Polygala
irregularis
d. Psilotum nodum
Correct answer: b, Dipcadi montanum, a rare flowering plant that once
found in abundance on the slopes of Nelliampathy, is on the verge of extinction
in Kerala, largely due to unchecked granite quarrying.
76. The relationship between hermit crab and sea-anemone is a typical
example of
a. Allelopathy
b. Obligatory
mutualism
c.
Proto-co-operation
d. Endosymbiosis
Correct answer: c, Proto-co-operation is a type of interaction where
both population are benefitted but not obligatory i.e. not essential for
survival of either population. This is a non-obligatory mutualism. The
relationship between hermit crab and sea-anemone is an example of
protocooperation. The crab uses the gastropod shell as a portable shield and
the sea anemone eats the leftover food which is protected from its predators by
stinging cells of the sea anemone.
77. Psammosere can be defined as the succession which starts on
a. Secondary bare
area
b. Normal soil
with moderate amount of water
c. Sand
d. Primary bare
area
Correct answer: c, Psammosere is defined as the succession which
starts on sand.
78. Artemesia tridentata is a good example of
a. Eurythermal
plant
b. Stenothermal
plant
c. Microthermal
plant
d. Megathermal
plant
Correct answer: a, Plants of wide limits of tolerance of heat are
called eurythermal plants. Artemisia tridentata is
regarded as a good example of eurythermal plant.
79. Which of the following points about Scotophilous plants is
correct?
a. They grow in shady areas.
b. Inter-nodes are elongated.
c. Plants are well branched and bushy.
d. Epidermis is made up of thick walled cells.
a. c and d
b. a and b
c. a and c
d. b and d
Correct answer: b, Scotophilous plants grow best at lower light
intensities i.e. they grow in shady areas. The shoots of these plants show
normal growth and inter-nodes are elongated. These plants show less branching
and their epidermis is made up of comparatively thin-celled walls.
80. _____ are very small plants that can grow in ultra low
temperatures of Alpine region.
a. Hekistotherm
b. Microtherms
c. Mesotherms
d. Megatherms
Correct answer: a, Hekistotherm are very small plants (like grasses)
of Arctic and Alpine regions (above 16000 feet in tropics and 12000 feet in
temperate) that can grow in ultra low temperatures.
81. Reproductive cooperation is interaction among
the species for continuance of species. A kind of cooperation in which
partnership of male and female lasts throughout life is seen in which of the
following?
a. Sawns,
sparrows and wild turkey
b. Swans, wolves
and foxes
c. Sparrows,
wolves and swans
d. Rats, sparrows
and deer
Correct answer: b, Swans, wolves and foxes are monogamous. They form
long term bonds and may remain together for several breeding seasons without
elaborate courtship
82. Any increase or decrease in number of individuals in a
population from its equilibrium state is called population fluctuation. It may
occur due to which of the following?
a. Fast or slow
growth of population
b. Immigration or
emigration
c. Predation
d. All of the
above
Correct answer: c, Any increase or decrease in number of individuals
in a population from its equilibrium state is called population fluctuation. It
may occur due to change in physical environment or due to predators.
83. Which of the following do not exhibit inter-specific
competition?
a. Individual
grass plants in lawn
b. Squirrels and
Chipmunks
c. Desert coyote
and sidewinder rattlesnake
d. Sponges and
Corals
Correct Answer: a, Plants of the same species, that receive nitrogen
and water from the same resource pool, exhibit intra-specific competition, such
as individual grass plants in a lawn.
84. Waggle dance of honey bees is indicative of which of the following?
a. A gesture to
attract mates
b. Danger in the
vicinity
c. Information
about availability of food
d. Direction and
distance of food from the bee hive
Correct answer: d, Waggle dance of honey bees indicates direction and
distance of food from bee hive. The waggle dance is really a round dance with
tail wagging in the middle. The further away the food source, the more waggles
there are in the dance. The bee increases the waggle part of the dance by 1
second for every km of distance
85. Directions: Choose the incorrect
sentence from the following.
a. Dry weather causes clay
soil to bake hard and crack on the surface.
b. Silty soils are
fertile and drain more effectively than clay
c. Sandy soils have poor
fertility
d. Clay holds more
moisture than silt
Correct answer: b, Silt holds more moisture
than clay because silt particles are smaller than clay. Soils with smaller
particles have a larger surface area and a large surface area allows a soil to
hold more water.
86. Hermit crab and sea anemone exhibit a typical interaction which is
known as
a.
Proto-co-operation
b. Obligatory
mutualism
c. Allelopathy
d. Endosymbiosis
Correct answer: a, Proto-co-operation is a type of interaction where
both populations are benefitted but not obligatory, i.e. not essential for
survival of either population. This is a non-obligatory mutualism. The
relationship between hermit crab and sea anemone is an example of
proto-co-operation. The crab uses the gastropod shell as a portable shield and the
sea anemone eats the leftover food which is protected from its predators by
stinging cells of the sea anemone.
87. according to Red List, Asiatic wild ass is a/an
a. Extinct
species
b. Endangered
species
c. Nearly
threatened species
d. Vulnerable species
Correct answer: c, As per Red List, Asiatic wild ass is assessed as
'near threatened' (NT) because a population decline of at least 20% is
projected over the next three generations.
88. According to the light requirement for flowering, all of the
following are short day plants, except:
a. Tobacco
b. Soybean
c. Pea
d. Paddy
Correct answer: Pea is a long day plant as it flowers when exposed
to longer photoperiods. It is also a short night plant.
89. Roots penetrate very easily in the soil which has
a. Size of
particles less than 0.02 mm
b. Size of
particles between 0.002 to 0.02 mm
c. Size of
particles between 0.02 to 2.00 mm
d. High water
holding capacity
Correct answer: c, Sandy soils have size of particles between 0.02 and
2.00 mm. Roots penetrate very easily in this type of soil.
90. Mycorrhiza is endotrophic in the case of
a. Oak
b. Maple
c. Pinus
d. Vanilla
Correct answer: d, Vanilla (orchid family) has endotrophic mycorrhiza.
In this case, the mycelia of mycorrhizic fungus enter into cortex of the roots
and reside intracellularly
91. Which of the following is the correct pair of the highest and
the lowest level of organisation, respectively?
a.
Ecosystem-Landscape
b. Landscape-Population
c.
Population-Community
d.
Community-Ecosystem
Correct answer: b, The correct pair of the highest and the lowest
level of organisation is 'Landscape - Population'. The highest level of
organisation is the landscape which is delimited by a particular climate or
geographical area. A population is all the organisms of the same group or
species, which live in a particular geographical area, and have the capability
of interbreeding
92. Reindeer live in a predator-free environment. Which of the
following statements are true about the growth model of reindeer's growth?
a. The rate of the growth becomes faster as the time passes.
b. The rate of the growth becomes slower as the time passes.
c. The graph of this model is J-shaped.
d. The graph of this model is S-shaped.
a. a and c
b. a and d
c. b and d
d. b and c
Correct answer: a, Model of reindeer's growth is exponential growth
model. Here, the rate of change increases over time. The rate of the growth
becomes faster as the time passes and the
graph of this model is J-shaped.
93. According to Malthus, the
positive checks on population control were
a. Floods,
draughts and Famines
b. Abstinence,
draughts and Famines
c. Moral
restraint, Abstinence and Postponement of marriage
d.Hunger, epidemic
and wars
Correct answer: d, According to Malthus, the positive checks to reduce
the population size were hunger, epidemic and wars. They increase the mortality
rate and decrease the life expectancy.
94. In Hydra-Chlorella interaction, Hydra helps Chlorella by
a. Providing
shelter
b. Providing
minerals
c. Protecting
from predators
d. Absorbing
water
Correct answer: a, Hydra provides shelter to Chlorella when associated
symbiotically to it.
95. Succession
on a newly exposed island is an example of
a. Primary succession
b. Secondary succession
c. Autogenic succession
d. Allogenic succession
Correct
answer: a, Succession on a newly exposed island is a
suitable example for primary succession. Primary succession begins on a sterile
area which was not previously occupied by any community.
96. In
Parasitodism, the larval and adult forms of parasite are respectively
a. Free living, Endoparasite
b. Endoparasite, free living
c Both are endoparasites
d. Both are free living
Correct
answer: b, In Parasitodism,
the larval form completes its life cycle inside the host, thus it acts as
Endoparasite, The adult form is free living.
97. The
relationship exhibited by Myxotricha paradoxa and bacteria living inside
the Australian termites is
a. Proto-co-operation
b. Symbiosis
c. Mutualism
d. Competition
Correct
answer: c, Mixotricha forms mutualistic relationships with bacteria living inside the termite.
There are a total of four species of bacterial symbionts. While Mixotricha has four anterior flagella, it does not use
them for locomotion, but more for steering. For locomotion, about 250,000
hairlikeTreponema
spirochetes, a species of helical bacteria, are attached to the cell surface and
provide the cell with cilia-like movements. Mixotricha also has rod-shaped bacteria arranged
in an ordered pattern on the surface of the cell; both of these types are ectosymbionts. In addition it
has spherical bacteria inside the cell; these endosymbionts function as mitochondria, which Mixotricha
lacks.
98. Graphis, Rhizocarpon and Lecidia in Xerosere constitutes the
a. Primary community
b. Pioneer community
c. Climax community
d. Intermediate community
Correct
answer: Graphis, Rhizocarpon and Lecidia in Xerosere
constitutes the pioneer community. Pioneer community comprises of the organisms
that colonizes the xeric rock for the first time.
99. In any Hydrosere, the pioneer community is
a. Blue-green algae
b. Phytoplanktons
c. Submerged plants
d. Plants with broad leaves
Correct answer: b, In any hydrosere the pioneer community is
constituted by phytoplanktons. They generate a huge biomass and on death and
decay add organic matter to the bottom which helps in the growth of other
plants.
100. Which factor maintains
distinctive traits of the species?
a. Continuous inter-communication
b. Geographical isolation
c. Reproductive isolation
d. Specific niche
Correct
answer: c, Reproductive isolation maintains distinctive
traits of the species.
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