i. Eurythermal plant species _______________ ii. A hot water spring organism _______________ iii. An organism seen in deep ocean trenches _______________ iv. An organism seen in compost pit...

Solution - Yes, light factor affects the distribution of organisms. For photosynthesis light is an important factor . The small plants in the forests are usually overshadowed by tall, canopied tree

Solution -  Na+, K+, Ca2+, Mg2+ and Cl-. Are the elements responsible for making soil saline . When the salt concentration in water is 3 – 6 g/l then soil starts becoming saline .

Solution - Yes, regional and local variations exist within each biome.

Solution – the adaptations include :  loss of unnecessary sense organs . presence of adhesive organs  or suckers to cling on to the host , loss of digestive system and High reproductive capacity

Solution - According to Gause’s principle , no two species can live in the same niche and hence one of them need to be eliminated . But in the given condition two herbivorous species are living...

Solution - POSITIVE POPULATION INTERACTIONSSpecies A + +Species B + 0Nature of interaction Mutualism Commensalism

Solution - It shows a population growing in a habitat having limited resources. Sigmoid type of growth curve would be obtained

Solution - The above graph indicates  a population growing in a habitat with limited resources. The graph represents  an initial lag phase. After that, a rise  in population takes place known as...

Solution - Figure ‘A’ is a pyramid-shaped figure. This structure has a larger base than the mid and the top. Status: This shape indicates the population would grow rapidly. Figure ‘B’ is an inverted...

Solution – A) A population has birth rate and death rate , whereas an individual has birth and death. B) The population density is referred  as the individual per unit area and density changes...

i. Which one of the figures shows mutualism? ii. What kind of association is shown in D? iii. Name the organisms and the association in C. iv. What role is the insect performing in B? Solution – i)...

Species ASpecies BType of interactionExample+ + +– + …A……….………B……….. …………C…….. Commensalism……D…… ………E… ……F……. Solution: A = 0 B = Parasitism C = Mutualism D = Commensalism E = Cuscuta D = Lichen E =...

a) Migratory animal b) Camouflaged animal c) Predator animal d) Biological control agent e) Phytophagous animal f) Chemical defence agent Solution: a) Migratory animal – Siberian crane, salmon,...

Solution – four characters employed in the human population census are : Natality and mortality Sex ratio Population density Age distribution

Solution - a condition wherein the population neither grows nor declines is termed as zero population growth .

Solution - an altitude beyond which no tree is seen and beyond the tree line, only shrubs and herbs are found is termed as tree line.

Solution -  Escherichia coli and Lactobacillus. Are the two scientific names microorganisms inhabiting the human intestine

Solution - The association in which one is Lianas and other is trees is commensalism . In such type of association  one species is benefitted and the other is neither benefitted nor harmed . The...

Solution - the association developed  is a type of mutualism relation that is both the interacting species are benefitted.

a. Bacteria _______________ b. Banyan _______________ c. Deer _______________ d. Fish _______________ Solution - Solution: a. Nos. / Vol b. Coverage / area c. Biomass / area d. Nos. / area e. Wt. /...

Solution: Plant NameTypea. Hydrillab. Typhac. Nymphaead. Lemnae. Vallisneria………………………………………………………………… Solution - a. Submerged b. Rooted emergent c. Rooted with floating leaves d. Free- floating e....

a. Salvinia b. Opuntia c. Rhizophora d. Mangifera Solution - Solution: a. Hydrophyte b. Xerophyte c. Halophyte d. Mesophyte

a. Burrowing b. Building cubes c. Holdfasts / peduncle Find suitable substratum against each adaptation Solution - substratum are a. Sandy b. Muddy c. Rocky

Solution - the sunlight passes deep water to reach the plant . Floating plants get high intensity of the sunlight because they are on the surface , while submerged plants are under the water

Solution - Heliophytes : are the plants which need high intensity sunlight , thus also known as sun-loving plants . Example sunflower . Sciophyte : They require low-intensity sunlight , hence known...

Solution - Freshwater fishes require contractile vacuole to remove the excess water because of the low salt concentration

Solution – the fish may not survive if it is placed from fresh water to the seawater . Sea fish are exposed to high concentration of salt , whereas the fishes of fresh water are exposed to low...

Solution -  Tamil Nadu and on the east coast of India the region is tropical and has high salinity .  The influx of freshwater is not there and no silation is there . All these factors are not found...

Solution – ectoparasite : parasites which  feeds on the external surface of the host organism and attaches on them during feeding . For eg. Ticks on dog Endoparasite :  which  lives...

Solution – in commensalism one species if benefitted and the other one remains unaffected . Example : like Interaction between cattle egret and grazing cattle

Solution - High altitude sickness known as mountain sickness has following symptoms  breathlessness, fast breathing, nausea, vomiting, headache etc

Solution - organisms  feeding on plant sap and other plant parts called Phytophagous.  For eg. insects and other invertebrates

Solution – in limited resources the pattern of growth will be exponential

Solution - adaptation to survive during unfavorable conditions is termed as diapause . It’s the phase of suspended development for some organism

Solution -  it is a behavioural adaptation to avoid extreme heat and desiccation in the hot summer season

Solution - the capacity of the organism to maintain a constant internal environment inspite of varying outer environmental conditions is called as homeostasis

Solution - thinner atmosphere and absence of dust particle is the reason for the altitude areas to have brighter sunlight and lower temperatures as compared to plains .

Solution – mangrove plants are emergent land plants that can tolerate the salinities of the sea

Solution - Mycorrhiza is a type of fungi , which grows in association with the plant roots.

Solution – the association is called as commensalism

Solution - the type of interaction between two species in which one species gets advantage by the other and the other species does not get affected is known as commensalism

Solution – interaction between two same species is termed as intraspecific interaction

Solution - species which cannot tolerate fluctuations in the degree of salt in the water are termed as Stenohaline species

Solution - Species that can tolerate a wide range of salinity are called Euryhaline

Solution -organisms that can adapt to a wide range of temperature changes are known as Eurythmic species

Solution - Species that can tolerate a narrow range of temperature are called Stenothermal species.

a. Banana b. Mango c. Tomato d. Eucalyptus correct option – ( a ) explanation – banana is a perennial plant . It sexually reproduces only once in its life time . It gives flower only once in the...

a. Sandalwood b. Mistletoe c. Orobanche d. Ganoderma correct option –(a ) explanation – sandalwood is observed as partial root parasite because it fulfil its nutritional demands from other plants ....

a. bacteria and fungus b. alga and bacterium c. fungus and alga d. fungus and virus correct option –( c ) explanation – lichens are symbiotic association between fungi and photosynthetic partners...

a. one species is harmed and other is benefitted b. one species is harmed and other is unaffected c. one species is benefitted and other is unaffected d. both the species are harmed. correct option...

a. 25 million b. 17 million c. 20 million d. 18 million correct option –( b ) explanation – we apply the exponential formula for population growth and will find it that 17 million people will be...

a. 128 b. 24 c. 64 d. 32 correct option –( c ) explanation – by binary fission the protozoan divides into two . I fit  goes like this then after 6 years the population of protozoan will be 64 ....

a. Natality > mortality b. Immigration > emigration c. Mortality and emigration d. Natality and immigration correct option –( c ) explanation – mortality means death and emigration ( moving...

a. Pugmarks only b. Pugmarks and faecal pellets c. Faecal pellets only d. Actual headcounts correct option –( b ) explanation – tiger census is carried out in our country every year . It is used to...

a. It will decline b. It will stabilise c. It will increase d. It will first decline and then stabilize correct option –( c ) explanation – if there are more young individuals as compared to older...

for the same population mentioned in the previous question (Question 10)? a. 100 b. 200 c. 50 d. 150 correct option –( b ) explanation – initial number of paramecium= 50 number of paramecium after...

transplanted outside the forest in a park? a. It will grow normally b. It will grow well because it is planted in the same locality c. It may not survive because of a change in its micro-climate d....

a. Lianas and climbers b. Shrubs c. Tall trees d. Herbs correct option – ( c ) explanation – the canopy over the tall trees is formed in the form of foliage over the forest . They are very dense ,...

a. 18 – 25°C and 150 – 400 cm b. 5 – 15°C and 50 – 100 cm c. 30 – 50°C and 100 – 150 cm d. 5 – 15°C and 100 – 200 cm correct option – ( a ) explanation – biotic and abiotic factors compose the...

a. shorter ears and longer limbs b. longer ears and shorter limbs c. longer ears and longer limbs d. shorter ears and shorter limbs correct option –( d )explanation – Allen’s rule is that in a warm...

a. the surface area of the ocean b. an ecologically adapted zone c. the physical position and functional role of a species within the community d. formed of all plants and animals living at the...

a. a component in the ecosystem b. composed of the plants present in the soil c. life in the outer space d. composed of all living organisms present on earth which interact with the physical...

a. A polluted area b. The bottom of a lake c. A zone of transition between two communities d. A zone of developing community correct option –( c ) explanation – ecotone is a transition area between...

a. Relation of heterogeneous populations to its environment b. Relation of an individual to its environment c. Relation of a community to its environment d. Relation of a biome to its environment...