Tag: ecology and environment

Questions Related to ecology and environment

Refer to the table below containing data obtained for a rabbit population over a period of several years.

Year Number of rabbits
1 4
2 17
3 62
4 245


Ultimately, the amount of nutrients and other resources would become limiting. What would happen to the rabbit population at that time?

population and how it changes human population ecology and environment zoology

  1. It would reach the carrying capacity of the environment.

  2. It would continue to grow indefinitely.

  3. It would engage in intraspecific competition.

  4. Both A and B.

  5. Both A and C.

Show answer
Correct Option: E
Explanation:

If the nutrients and other resources are limited they will limit the population size and it will reach the "carrying capacity" of the environment and rabbits will compete with one another (intraspecific competition) for these limited nutrients. Therefore, the correct answer is option E.

A biological community can be best described by

population and how it changes human population ecology and environment zoology

  1. A group of individuals of the same species that live together in the same area at the same time

  2. All populations of different species that live and interact in the same area

  3. All populations of different species that live and interact in the same area and the abiotic environment

  4. The part of earth where life exists

  5. A group of organisms that share similar ecological niches in different areas

Show answer
Correct Option: B
Explanation:

The population is individuals of same species that occupy a specific area. The ecosystem is an assemblage of different species of an area and abiotic factors of a geographical area and also takes account of the interaction between them. The part of the earth where life exists is referred to as biosphere. A group of organisms that share similar ecological niches in different areas constitute species. The community is a group of populations of different species living together in a habitat and interacting with each other. Thus, the correct answer is B.

Two populations of a species of pine tree are located on opposite sides of a mountain range. The two populations are genetically similar to each other.
An invasive beetle infestation kills 80% of the trees on the west side of the range. The beetle population does not spread to the eastern side of the range, and the east tree population does not experience any beetle related loss. After the infestation, the western tree population increases in size again.
What is the expected outcome of genetic testing comparing the two populations?

population and how it changes human population ecology and environment zoology

  1. The genetic diversity of the west population is higher than the east population.

  2. The phenotypic variation of the west population is higher than the east population.

  3. The two populations are less genetically similar than they were prior to the beetle infestation.

  4. The two populations remain genetically similar.

Show answer
Correct Option: C
Explanation:

Due to beetle infestation, 80% of the trees on the west side of the range were killed. This will result in the alteration of allele frequencies. Certain alleles are lost during infestation. In the small population of the west side, genetic diversity is less compared to that of a large population in the east. Due to less genetic diversity, phenotypic variations will also be lower on the west side. Hence, the two side of populations will be less genetically similar than the earlier. 

Thus, the correct answer is 'The two populations are less genetically similar than they were prior to the beetle infestation.'

For natural selection to occur, which of the following must be true for a population of organisms?

population and how it changes human population ecology and environment zoology

  1. Phenotypic variations must be based on genetic variations rather than on varying environmental conditions.

  2. The population must be occupying the same niche as another local population.

  3. Organisms in the population must be capable of sexual reproduction.

  4. Food resources must be limited.

Show answer
Correct Option: A
Explanation:

Evolution takes place due to various reasons like natural selection, mutation, genetic drift. Phenotypic variations must be based on genetic variations rather than on varying environmental conditions. Sexual reproduction results in the genetic variation but does not affect the natural selection. Also, limited food resources may drive natural selection but is not the reason for natural selection to occur.

Thus, the correct answer is 'Phenotypic variations must be based on genetic variations rather than on varying environmental conditions.'

A population is made up of

population and how it changes human population ecology and environment zoology

  1. All individuals of any kind

  2. All groups of organisms in an area at any one time

  3. Groups of individuals of different kinds in an area

  4. Individuals of the same kind in an area at a given time

Show answer
Correct Option: D
Explanation:

A population is all the organisms of the same group or species, which live in a particular geographical area, and have the capability of interbreeding. They are capable of interbreeding or reproduction.

So the correct option is 'individuals of the same kind in an area at a given time'.