A-Level Notes > Eastbourne College A-Level Notes > OCR Biology F215 Notes

Populations And Sustainability Notes

This is a sample of our (approximately) 4 page long Populations And Sustainability notes, which we sell as part of the OCR Biology F215 Notes collection, a A package written at Eastbourne College in 2013 that contains (approximately) 48 pages of notes across 10 different documents.

Learn more about our OCR Biology F215 Notes

The original file is a 'Word (Docx)' whilst this sample is a 'PDF' representation of said file. This means that the formatting here may have errors. The original document you'll receive on purchase should have more polished formatting.

Populations And Sustainability Revision

The following is a plain text extract of the PDF sample above, taken from our OCR Biology F215 Notes. This text version has had its formatting removed so pay attention to its contents alone rather than its presentation. The version you download will have its original formatting intact and so will be much prettier to look at.

5.3.2. Populations and sustainability Context There are many factors that determine the size of a population. For economic, social and ethical reasons ecosystems may need to be carefully managed. To support an increasing human population, we must try to use biological resources in a sustainable way. Candidates should be able to:

Explain the significance of limiting factors in determining the final size of a population. Any factor that prevents a population from increasing in size is a limiting factor. At any given time, there's usually just one factor limiting population growth, but different limiting factors come into play at different times. The limiting factor may operate seasonally. Limiting factors can be both abiotic (non-living) and biotic (living): Abiotic factors e.g. Temperature; water; pH; light; soil; mineral supply; current (wind water); topography (altitude, slope, aspect); catastrophes and pollution.

Explain the meaning of the word carrying capacity. Limiting factors place an upper limit on the size of population that can be sustained. This is known as the "carrying capacity" - i.e. the maximum population supported by a particular ecosystem.

Describe predator-prey relationships and their possible effects on the population sizes of both the predator and the prey. In some cases, there's evidence that the size of predator population is influenced by the size of prey population and vice versa.

The population of the prey species rises first, followed by that of the predator. This makes sense, because we would expect the population of the predatory mite to be able to grow only when it has plenty of food - so the rise in the

****************************End Of Sample*****************************

Buy the full version of these notes or essay plans and more in our OCR Biology F215 Notes.