Predator/prey relationships Flashcards
What is a predator
A predator is an organism that kills and feeds on another organism, e.g. a lion.
What is a prey
The prey is the organism that the predator eats, e.g. a zebra
What is an apex predator?
An apex predator is at the top of a food chain and has no predators, e.g. killer whales, tiger sharks, hawks, owls.
Predator and prey relationship
A predator and its prey evolve together. The predator must evolve characteristics to catch its prey, e.g. speed, stealth, camouflage, highly developed senses, sharp and piercing mouth parts, poison to kill its prey, immunity to the prey’s poison. At the same time, the prey evolves characteristics to avoid being eaten, e.g. speed, camouflage, highly developed senses, rapid responses, poison, protective body coverings
Biological control- predator and prey relationships
Predator/prey relationships serve as biological controls and keep the numbers of organisms in an ecosystem relatively constant. If a predator over hunts its prey, the prey population will decrease and this will cause the predator population to decrease. The prey population will then begin to increase again, which will allow the predator population to increase.
Biological control- humans using predator/prey relationships to control pests
Humans can use predator/prey relationships to control pests. This is known as biological control. It involves introducing a natural predator of the pest into the environment, e.g. mongooses were introduced into Barbados to control the snake population.
Rules in making a food chain
mention whether it’s terrestrial or aquatic
mention the trophic levels..it moves up the food chain (primary is number 1)
mentions animal status (consumer or producer quaternary)
Explain why food chains rarely contain more than four or five trophic levels.
Food chains rarely contain more than four or five trophic
levels because energy and biomass are lost at each
successive level in the food chain. LOOK AT NOTES.
Decomposers
Decomposers are micro-organisms that feed
saprophytically on dead and waste organic matter causing
it to decompose.
Why are decomposers important/ What do they do?
They secrete digestive enzymes that breakdown complex organic compounds into simple organic compounds which they absorb. During this process, they release carbon dioxide and inorganic mineral nutrients in the form of ions, e.g. nitrates and sulfates, into the environment. These can then be reabsorbed and re-used by plants.
Symbiosis
any close relationship between two organisms of different species. Symbiotic relationships can be divided into the following types:
* parasitism
* commensalism
* mutualism.
Detritivores
Detritivores are animals, e.g. earthworms, woodlice, millipedes and sea cucumbers, which feed on pieces of decomposing (dead) organic matter, breaking them down into smaller fragments.
