Organisms and Populations
- Select the mismatch:
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Rhodospirillum is facultative anaerobe and free living nitrogen fixer. Mycorrhiza show symbiotic relationship between fungi and roots of higher plants.
Correct Option: A
Rhodospirillum is facultative anaerobe and free living nitrogen fixer. Mycorrhiza show symbiotic relationship between fungi and roots of higher plants.
- Mycorrhizae are the example of:
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Mycorrhizae is a symbiotic association between fungi and roots of higher plants.
Correct Option: C
Mycorrhizae is a symbiotic association between fungi and roots of higher plants.
- Gause’s principle of competitive exclusion states that:
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Gause’s principle of competitive exclusion can be restated to say that no two species can occupy the same niche indefinitely when resources are limiting. Certainly species can and do coexist while competing for some of the same resources. Nevertheless, Gause’s theory predicts that when two species coexist on a long-term basis, either resources must not be limited or their niches will always differ in one or more features; otherwise, one species will outcompete the other and the extinction of the second species will inevitably result, a process referred to as competitive exclusion.
Correct Option: C
Gause’s principle of competitive exclusion can be restated to say that no two species can occupy the same niche indefinitely when resources are limiting. Certainly species can and do coexist while competing for some of the same resources. Nevertheless, Gause’s theory predicts that when two species coexist on a long-term basis, either resources must not be limited or their niches will always differ in one or more features; otherwise, one species will outcompete the other and the extinction of the second species will inevitably result, a process referred to as competitive exclusion.
- When does the growth rate of a population following the logistic model equal zero? The logistic model is given as dN/dt = rN(1–N/K)
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In logistic growth model population growth equation is described as
dN = rN 
1 - N 
dt K
N = population density at time t;
r = Intrinsic rate of natural increase;
K = carrying capacityWhen N/K = 1; 1 – N = 0 K Therefore, dN = 0 dt Correct Option: A
In logistic growth model population growth equation is described as
dN = rN 1 - N dt K
N = population density at time t;
r = Intrinsic rate of natural increase;
K = carrying capacityWhen N/K = 1; 1 – N = 0 K Therefore, dN = 0 dt
- In which of the following interactions both partners are adversely affected?
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Competition occurs for light, food and space among organisms in which all partners are adversely affected in an ecosystem.
Correct Option: D
Competition occurs for light, food and space among organisms in which all partners are adversely affected in an ecosystem.
