Organisms In The Environment: Answers

Define the following terms: population, community, habitat and ecosystem.

• A population is all the members of the same species which live in the same area.

• A community is all of the populations of difference species which live in the same area and interact with each other.

• The habitat is where an organism lives.

• An ecosystem is a community of organisms and the habitat in which it lives (both the biotic and abiotic factors).

Describe the method you would use to count the population of daffodils in a large field.

You would estimate population size using a quadrat. You would place the quadrat randomly in the field by generating coordinates using a random number generator. You would then count the number of daffodils inside each quadrat. You would repeat this process so that a large number of quadrats have been used, then calculate a mean.

What is the difference between biotic and abiotic factors? Give examples of each.

Biotic factors are living factors, such as the numbers of predators in the area, the amount of food available and disease. Abiotic factors are non-living factors and include the amount of precipitation, pH of the soil, temperature and light intensity.