B18 - Organisms and their environment Flashcards
explain energy flow in biological systems
The sun is the principal source of energy input
light energy from the sun and chemical energy in organisms transfers to the environment
producer definition
an organism that makes its own organic nutrients, generally using energy from sunlight, through photosynthesis
ecosystem definition
a unit containing all of the organisms in a community and their environment, interacting together
herbivore definition
an animal that gets its energy by eating plants
carnivore definition
an animal that gets its energy by eating other animals
omnivore definition
an animal that gets its energy by eating plants and other animals
community definition
all of the populations of all the different species in an ecosystem
population definition
a group of organisms of one species, living in the same area at the same time
habitat definition
the place where an organism lives
consumer definition
an organism that gets its energy from feeding on other organisms
biodiversity definition
the number of different species that live in an area
decomposers definition
organisms that break down organic substances outside their bodies, releasing nutrients from them that other organisms can use
get its energy from dead or waste organic material
trophic level definition
otherwise known as feeding level
the position of an organism in a food chain and food web (producer, primary consumer/herbivore, secondary consumer/carnivore, tertiary consumer/predator, quaternary consumer)
predator definition
kill prey for food
tertiary consumer
prey definition
the animals that are killed by the predators/tertiary consumers
primary consumer definition
animals that eat or consume the producers
herbivores
secondary consumer definition
animals that consume the primary consumers
carnivores
tertiary consumer definition
animals that eat the secondary consumers/carnivores
these are hunters that hunt, catch, and kill their prey for food
they are not normally killed by other animals
top of the food chain
layers in a woodland
canopy layer - trees
shrub layer
herb layer
ground layer
explain why food chains usually have fewer than five trophic levels
energy is lost from one trophic level to another which means each trophic level has to eat more of the last trophic level to have enough energy, which limits food chains to fewer than five trophic levels
explain why the transfer of energy from one trophic level to another is often not efficient
as one trophic level animal eats another organism, it does not get all the energy that organism started with, as some of the energy was used and the animal could not take all the energy when it ate the animal
explain why it is more energy efficient for humans to eat crop plants than to eat livestock that have been fed on crop plants
since humans eating plants is only one process compared to humans eating livestock that ate plants, which is two processes, so there is less energy lost due to one organism consuming another organism, which makes it more energy efficient
describe the carbon cycle (6)
photosynthesis
respiration
feeding
decomposition
formation of fossil fuels
combustion
decay meaning
caused by bacteria and fungi breaking down dead material and animal waste. As they do this, they respire and so release carbon dioxide
photosynthesis word equation
carbon dioxide + water –> glucose + oxygen
respiration word equation
glucose + oxygen –> water + carbon dioxide
combustion word equation
hydrocarbon fuel + oxygen –> carbon dioxide + water
death definition
the ending of life
burning/combustion definition
release of energy from fossil fuels
respiration definition
the release of energy in living cells which produces carbon dioxide
the chemical reactions in cells that break down nutrient molecules and release energy for metabolism
feeding/consumption definition
consumers taking in food
photosynthesis definition
the process by which a green plant makes its own food
burial and sedimentation definition
formation of fossils
