Population Size

Question 1

What is carrying capacity?

Answer 1

It is the maximum population size that can be maintained over a period of time in a particular habitat

Question 2

Explain the relationship between predator and prey (interdependence)

Answer 2

• prey - depend on food source, generally a producer
- good supply of food in spring/summer
- more rabbits have more food so more survive to reproduce
- more offspring also survive as food supply is plentiful
- so population size increases
• predator - e.g. Fox, population then increases
- more food available (rabbits) so more predators survive to reproduce and more offspring survive
• prey - population decreases as more prey are caught by increased predator numbers
• predator - population decreases as less prey available
- not enough to support high predator numbers so less survive and reproduce
• prey - population increases as less predator so more prey survive and reproduce

Question 3

What factors should be considered with interdependence?

Answer 3

• predator population and prey population never gets to the same size
• predators have more than one food source
• prey animals are preyed on by more than one predator

Question 4

What factors limit the final size of a population?

Answer 4

• abiotic factors 
     - availability of food, water, light, oxygen, space, shelter etc 
• biotic factors 
     - interspecific competition 
     - interspecific competition 
     - predation 
     - parasites