Chapter 19: Organisms and their environment Flashcards
Describe the flow of energy through living organisms:
light energy from the sun- plants use it to photosynthesis- animals get chemical energy from eating plants or animals that eat plants- throughout life they use that energy to survive and some is given off to the environment- when they die their bodies get decomposed and go back into the earth.
Define food chain:
shows the transfer of energy from one organism to the next, beginning with a producer.
Define trophic levels:
the position of an organism in a food chain, food web, pyramid of numbers and pyramid of biomass.
Why is the transfer of energy from one trophic level to the other inefficient?
Because not all of the energy that the plant gets from the sun of the animal gets from the plant is used as body mass but instead more used to keep the organism alive.
As the trophic levels increase there is less energy left to transfer.
Define food web:
a network of interconnected food chains.
Define producer:
an organism that makes its own organic nutrients, usually using energy from the sunlight, through photosynthesis.
Define consumer:
an organism that gets its energy by feeding on other organisms.
you get a primary, secondary, tertiary and quaternary consumer.
Define herbivore:
an animal that gets its energy by eating plants only.
Define carnivore:
an animal that gets its energy by eating other animals only.
Define omnivore:
an animal that gets its energy by eating both plants and animals.
Define decomposer:
an organism that gets its energy from dead or waste organic material.
Define population:
a group of organisms of one species, living in the same area, at the same time.
Define community:
all the populations of different species in an ecosystem.
Define ecosystem:
a unit containing community of organisms and their environment interacting together.
What is the lag phase of a population growth curve?
birth rate>death rate but population is small and so we don’t see much of a difference.
