Organisms and Populations — Page 4 | NEET Biology

Q31

Niche overlap indicates

A two different parasites on the same host

B sharing of one or more resources between the two species

C mutualism between two species

D active cooperation between two species

Correct Answer

Option B

Solution

(b) Niche overlap: two species share one or more resources in the same habitat.

Q32

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?

A Hydrilla

B Yucca

C Viola

D Banana

Correct Answer

Option B

Solution

(b) Yucca and its moth (Pronuba) have obligate mutualism.

Q33

Competition for light, nutrients and space is most severe between

A closely related organism growing in different niches.

B closely related organisms growing in the same area/niche.

C distantly related organisms growing in the same habitat.

D distantly related organisms growing in different niches.

Correct Answer

Option B

Solution

(b) Intraspecific competition (same species, same niche) is most severe.

Q34

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

A Competitive exclusion

B Character displacement

C Altruism

D Resource partitioning

Correct Answer

Option D

Solution

(d) Resource partitioning allows coexistence by exploiting different prey sizes.

Q35

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

A Stratification

B Natality

C Mortality

D Sex ratio

Correct Answer

Option A

Solution

(a) Stratification (vertical layering of species) is a community characteristic.

Q36

Gause's principle of competitive exclusion states that :

A more abundant species will exclude the less abundant species through competition.

B competition for the same resources excludes species having different food preferences.

C no two species can occupy the same niche indefinitely for the same limiting resources.

D larger organisms exclude smaller ones through competition.

Correct Answer

Option C

Solution

(c) No two species can occupy the same niche indefinitely when resources are limiting.

Q37

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

A Commensalism

B Mutualism

C Amensalism

D Parasitism

Correct Answer

Option C

Solution

(c) Amensalism/antibiosis: Penicillium produces penicillin that kills Staphylococcus.

Q38

The logistic population growth is expressed by the equation:

A

\mathrm{dt} / \mathrm{dN}=\mathrm{Nr}\left(\dfrac{K-N}{K}\right)

B

\mathrm{dN} / \mathrm{dt}=\mathrm{rN}\left(\dfrac{K-N}{K}\right)

C

\mathrm{dN} / \mathrm{dt}=\mathrm{rN}

D

\mathrm{dN} / \mathrm{dt}=\mathrm{rN}\left(\dfrac{N-K}{N}\right)

Correct Answer

Option B

Solution

(b) The logistic population growth is expressed by the equation dN/dt = rN[(K-N)/K] where N is population density at time t, r is the Malthusian parameter (rate of maximum population growth) and K is the carrying capacity.

Q39

Keystone species in an ecosystem are those

A present in maximum number

B that are most frequent

C attaining a large biomass

D contributing to ecosystem properties

Correct Answer

Option D

Solution

(d) Keystone species have disproportionately large impact on ecosystem despite small biomass.

Q40

Species occurring in different geographical areas are called as

A sibling

B sympatric

C allopatric

D neopatric

Correct Answer

Option C

Solution

(c) Allopatric species: same species in different geographical areas.