6.6.2 Interactions between populations Flashcards
Explain the relationship between a predator and it’s prey.
Predator’s population increases, and eats more prey. The prey’s population decreases, there’s not enough food for predators. Predators population decreases, and preys increases. As prey’s population increases, predators have more food and their population increases. This cycle continues.
What is predation a limiting factor for?
Limiting factor on a prey’s population size, that can affect predators population size.
Define competition.
The fight for limited resourced between organisms. As the intensity of competition increases the rate of reproduction decreases, while the death rate increases.
What are the two types of competition?
Intraspecific and interspecific competition
Define Intraspecific competition.
Competition between individuals of the same species.
Hoe does intraspecific competition help to keep the population size stable?
If population size drops, competition reduces and population size increases.
If population size increases, competition increases and the population size drops.
Define Interspecific competition.
Competition between individuals of different species.
What can interspecific competition affect?
Population size of a species and the distribution of species in an ecosystem.
What was Gause’s conclusion about interspecific competition?
Concluded that overlap between two species’ niches results in more intense competition. If two species have the same niche, one will be outcompeted. This is called the Competitive exclusion principle, and can be used to explain why particular species only grow in certain places.
What is a criticism of Gause’s conclusion?
Sometimes interspecific competition simply results in one population being much smaller than the other, with both population sizes remaining constant.
What is the difference between intraspecific and interspecific competition.
Intraspecific is between species. Interspecific is between different species.
Explain how a species’ population size can be affected by:
a) Intraspecific competition
b) Interspecific competition.
a) Can maintain a stable population size through increasing/reducing competition size dependent on the population size
b)Can affect what species make up a population size
Explain how competitive exclusion principle does not always apply in natural ecosystems.
In the wild, a wide range of variables may act as limiting factors for the growth of different populations, and may change over the course of a year.
