Chapter: Organisms and Population

Niche is

Which one of the following pairs is mismatched?

Keystone species in an ecosystem are those which

Niche of a species in an ecosystem refers to its

Tropical forests occur in India

Xeric environment is characterised by

Study of inter-relationships between living organisms and their environment is

The sum total of the population of the same kind of organisms constitute

What is true for individuals of same species?

Which part of the world has high density of organisms?

An association of individuals of different species living in the same habitat and having functional interactions is

Competition for light, nutrients and space is most severe between

Match the organisms in Column I with habitats in Column II
Column I                                        Column II
1. Halophiles                            i. Hot springs
2. Thermoacidophiles          ii. Aquatic environment
3. Methanogens                     iii. Guts of ruminants
4. Cyanobacteria                    iv. Salty area
Select the correct option from the following

It is much easier for a small animal to run uphill than for a large animal, because

The figure given below is a diagrammatic representation of response of organisms to abiotic factors. What do (i), (ii) and (iii) represent respectively?

(i)                          (ii)                                        (iii)
A. Conformer           Regulator                         Partial regulator
B. Regulator           Partial regulator                  Conformer
C. Partial regulator    regulator                            Conformer
D. Regulator              Conformer                      Partial regulator

Consider the following four statements (I-IV) about certain desert animals such as kangaroo rat.
I. They have dark colour and high rate of reproduction and excrete solid urine.
II. They do not drink water, breathe at a slow rate to conserve water and have their body covered with thick hairs.
III. They feed on dry seeds and do not require drinking water.
IV. They excrete very concentrated urine and do not use water to regulate body temperature.
Which two of the above statements for such animals are true?

. Annual migration does not occur in the case of

In which one of the following pair is the specific characteristic of soil not correctly matched?

In which one of the following habitats does the diurnal temperature of soil surface vary most?

Diffuse porous woods are characteristic of plants growing in

Special kinds of roots called pneumatophores are characteristics of the plants growing in

Temperature changes in the environment affect most of the animals which are

Extremities, tail and ear are relatively shorter in animals living in cooler regions as compared to those inhabiting warmer zones. This is

Desert plants are generally

Sunken stomata is the characteristic feature of

Which of the following does not have stomata?

Animals that can tolerate a narrow range of salinity are

Soil best suited for plant growth is

Soil particles determine its

A fertile agricultural soil appears dark coloured at the surface as compared to soil one metre down. The reason for colour of top soil is

River water deposits

Deep black soil is productive due to high proportion of

CAM helps the plants in

Two different species cannot live for long duration in the same niche or habitat. This law is

In which of the following plant sunken stomata are found?

Inspite of interspecific competition in nature, which mechanism the competing species might have evolved for their survival ?

In the exponential growth equation e represents

Amensalism can be represented as

Match the items in Column I with those in Column II.
Column I                                                   Column II
A. Herbivores-Plants                          (i) Commensalism
B. Mycorrhiza-Plants                        (ii) Mutualism
C. Sheep-Cattle                                  (iii) Predation
D. Orchid-Tree                                    (iv) Competition
Select the correct option.

The impact of immigration on population density is

According to Alexander von Humboldt

Which of the following is not an attribute of a population?

Secondary metabolites such as nicotine, strychnine and caffeine are produced by plants for their

Between which among the following, the relationship is not an example of commensalism?

Carnivorous animals-lions and leopards, occupy the same niche but lions predate mostly larger animals and leopards take smaller ones. This mechanism of competition is referred to as

Which of the following statements is correct?

Pinus seed cannot germinate and establish without fungal association. This is because

Match Column I with Column II.
Column I                                             Column II
A. Saprophyte                (i) Symbiotic association of fungi with plant roots
B. Parasite                     (ii) Decomposition of dead organic materials
C. Lichens                      (iii) Living on living plants or animals
D. Mycorrhiza               (iv) Symbiotic association of algae and fungi.
Choose the correct answer from the option given below:

Which one of the following plants shows a very close relationship with a species of moth, where none of the two can complete its life cycle without the other?

Natality refers to

Which one of the following population interactions is widely used in medical science for the production of antibiotics?

In a growing population of a country,

Asymptote in a logistic growth curve is obtained, when

Mycorrhizae are the example of

Gause’s principle of competitive exclusion states that

When does the growth rate of a population following the logistic model equal zero? The logistic model is given as

The principle of competitive exclusion was stated by

If ‘+’ sign is assigned to beneficial interaction, ‘–’ sign to detrimental and ‘0’ sign to neutral interaction, then the population interaction represented by ‘+’ ‘–’ refers to

Which of the following is correct for r-selected species?

In which of the following interactions both partners are adversely affected?

A biologist studied the population of rats in a barn. He found that the average natality was 250, average mortality 240, immigration 20 and emigration 30. The net increase in population is

A sedentary sea anemone gets attached to the shell lining of hermit crab. The association is

What type of human population is represented by the following age pyramid?

Consider the following four conditions (I-IV) and select a correct pair of them as adaptation to environment in desert lizards.
Conditions
I. Burrowing in soil to escape high temperature.
II. Losing heat rapidly from the body during high temperature.
III. Bask in sun when temperature is low.
IV. Insulating body due to thick fatty dermis.

Which one of the following is categorised as a parasite in true sense?

Which one of the following is one of the characteristics of a biological community?

A country with a high rate of population growth took measures to reduce it. The figure below shows age sex pyramids of populations. A and B twenty years apart. Select the correct interpretation about them

A high density of elephant population in an area can result in

The population of an insect species shows an explosive increase in numbers during rainy season followed by its disappearance at the end of the season. What does this show?

Geometric representation of age structure is a characteristic of

If the mean and the median pertaining to a certain character of a population are of the same value, the following is most likely to occur

The formula for exponential population growth is

Niche overlap indicates

Praying mentis is a good example of

Animals have the innate ability to escape from predation. Examples for the same are given below.Select the incorrect example

Mycorrhiza is an example of

The semilog of per minute growing bacteria is plotted against ime. What will be the shape of graph?

Choose the correct sequence of stages of growth curve for bacteria

Which type of association is found in between entomophilous flower and pollinating agent?

Which of the following is a correct pair?

Two different species cannot live for long duration in the sameniche or habitat. This law is

An orchid resembling the female of an insect, so as to be able to get pollinated is due to the phenomenon of

The concept that population tends to increase geometrically while food supply increases arithmetically was put forward by

Which of the following pair is correctly matched?

A mutually beneficial association necessary for survival of both partners are

The relation between algae and fungi in a lichen is

Phenomenon when organisms resembling others for escaping from enemies is

Association between sucker fish (Remora) and shark is