B2d - interdependence Flashcards
How will similar organisms in the same habitat compete
will be in close competition for resources such as food
What will members of the same species compete for and why(2)
For mates as well as other resources
So they can breed
Which is more significant and why, interspecific or intraspecific competition
intraspecific is often more significant because the needs of the 2 groups are identical so will compete for lots of resources(e.g. mates)
What is meant by the term ecological niche(2)
the unique way an organism has of surviving in its environment, e.g. where it lives and what it feeds on
similar organisms will occupy similar ecological niches similar
How do the populations of some predators and their prey show fluctuations in numbers(3)
They show cyclical fluctuations
+prey, +predator, prey, predator, +prey; this cycle repeats
the cycles of population for predator and prey are out of phase with each other as it takes a while for one population to respond to changes in the other population; e.g. it takes time to reproduce
Describe other types of interdependence between organisms(9)
parasitism
- one organism (parasite) benefits at the cost of the other (host)
- e.g. fleas live on skin of host and feed on blood
- e.g. tapeworms live in gut of host and feed on food
mutualism
- both species benefits
- e.g. cleaner species gain food by removing parasites
- e.g. pollination by insects rewarded by nectar
- e.g. nitrogenfixing bacteria in the root of nodules of leguminous plants(such as pea plants) - bacteria converts nitrogen into nitrates by fixing the nitrogen, which the plant uses; bacteria gains food from the plant cells produced by photosynthesis
What does the interdependence of organisms determine and how(2)
their distribution and abundance
some organisms depend entirely on other species to survive so where an organism lives and its abundance is often influenced by the distribution and abundance of these species
