Q. No.The principle of competitive exclusion was stated by?
1. C. Darwin
2. G. F. Gause
3. MacArthur
4. Verhulst and Pearl
| 1. | when N nears the carrying capacity of the habitat |
| 2. | when N/K equals zero |
| 3. | when the death rate is greater than the birth rate |
| 4. | when N/K is exactly one |
An association of individuals of different species living in the same habitat and having functional interactions is known as:
| 1. | Ecological niche | 2. | Biotic community |
| 3. | Ecosystem | 4. | Population |
In which of the following interactions both partners are adversely affected?
| 1. | Competition | 2. | Predation |
| 3. | Parasitism | 4. | Mutualism |
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:
| 1. | 15 | 2. | 05 |
| 3. | zero | 4. | 10 |
According to Darwin, organic evolution is due to:
| 1. | Interspecific competition. |
| 2. | Competition within closely related species. |
| 3. | Reduced feeding efficiency in one species due to the presence of interfering species. |
| 4. | Intraspecific competition. |
What type of human population is represented by the following age pyramid?
1. Stable population
2. Declining population
3. Expanding population
4. Vanishing population
| 1. | Human foetus developing inside the uterus draws nourishment from the mother |
| 2. | Head louse living on the human scalp as well as laying eggs on human hair |
| 3. | The cuckoo (koel) lays its eggs in a crow's nest |
| 4. | The female Anopheles bites and sucks blood from humans |
Study the four statements (a–d) given below and select the two correct ones out of them:
| (a) | A lion eating a deer and a sparrow feeding on grain are ecologically similar in being consumers |
| (b) | Predator starfish Pisaster helps in maintaining species diversity of some invertebrates |
| (c) | Predators ultimately lead to the extinction of prey species |
| (d) | Production of chemicals such as nicotine and strychnine by plants is metabolic disorder |
The two correct statements are:
1. a and d
2. a and b
3. b and c
4. c and d
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