chapter 12 Flashcards
what is mutualism?
the relationship in which 2 or more organisms support or benefit one another
what is parasitism?
the relationship in which the parasite benefits by obtaining food/nutrients from the body or its host (which can be plant or animal)
what is predator-prey relationship?
the relationship in which one feeds on the other organism
why is a shorter food chain more efficient?
because energy is lost to the surroundings as heat during respiration, and as chemical energy trapped in uneaten body parts, faces and excretory matter, less energy reaches the last consumer
why is a food web better than a food chain?
many consumers do not consume only one type of plant/animal. they may also share common food sources
example of decomposers
- worms
- bacteria
- fungi
why are decomposers important to the ecosystem?
decomposers break down the faeces of organisms and the remains of dead organisms and return the nutrients in them to the environment
why does the last organism get the least amount of energy?
during cellular respiration, part of the total energy released from food is used for cellular activities while the rest is transferred to the surroundings as heat.
This heat energy cannot be reused by the producers for photosynthesis
++ chemical energy is trapped within the faeces of the animals and uneaten body parts
why does the last organism receive the least amount of energy from the sun?
since approximately 90% of the energy is lost down the food chain, the last organism receives the least amount of energy from the sun
what is the role of the apex predator?
they help to regulate the population of the organism they feed on
effect on ecosystem if there is a drop in one organism in the food chain?
- the population of the organism (predator) it feeds on will increase
- this will cause the population of ___ (prey)to decrease because ____ is predator of ______
