Measuring the size and distribution of populations of organisms
I can describe how to identify species, estimate the population size of a species and how to investigate the effect of a factor on the distribution of this species.
Measuring the size and distribution of populations of organisms
I can describe how to identify species, estimate the population size of a species and how to investigate the effect of a factor on the distribution of this species.
Lesson details
Key learning points
- Keys can be used to identify organisms in their habitat.
- It is not possible to count all the organisms in a population, so we use sampling to estimate population size.
- Sampling organisms in habitats (e.g. a river using kick sampling and a net).
- Sampling animals using a pooter.
- Estimating populations using capture-mark-recapture.
Keywords
Classification key - A classification key is a series of questions about the features of organisms that help us to classify them correctly.
Population - A group of organisms of the same type in the same place is called a population.
Estimate - Estimate means to give an approximate value, for example, you can estimate the population of fish in a lake by sampling.
Sampling - Sampling is a survey of plants and/or animals which provides information about the populations of organisms.
Common misconception
Many pupils believe that in order to determine a population size within a habitat, all organisms within a habitat have to be counted.
Populations can be estimated using sampling techniques. As long as a sample size is large enough, it will provide a reliable estimate of the population size. Pupils should understand that counting all individuals in a habitat is very difficult to do.
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.What do we call a survey of plants and/or animals which provides information about the populations of organisms?
Q2.Light intensity is an example of ...
Q3.Which of the following pieces of apparatus would be useful to sample small organisms on the leaves of a tree?
Q4.What piece of equipment might be used to sample plants and slow-moving animals?
Q5.Match the following words with their definitions.
a feature that helps an organism to survive in a habitat
when the person carrying out an investigation affects the outcome
the range of different living organisms (species) that live in a place
the mass of living material in one or more organisms
Q6.A habitat provides organisms with food, shelter and a place to live. Which of the following might be the habitat of a robin?
Assessment exit quiz
6 Questions
Q1.What means to give an approximate value, for example, when sampling the population of fish in a lake?
Q2.What is the image an example of?
Q3.The image shows a sample of organisms found from a pond. Why has the net been emptied into a white tray which contains water?
