biology life on earth Flashcards
what is a species
A group of organisms who can interbreed to produce fertile offspring.
what is a population
The number of individuals within a species living in a particular area.
what is biodiversity
This is the variety of living organisms within an area.
what is a producer
An organism that can produce its own food using light energy from the sun.
what is a consumer
An organism who has to consume food to gain energy.
what is a food web
A diagram to show all of the interlinking food chains within an environment.
what is a food chain
Shows the feeding relationship between individuals.
example:
Grasses → Mountain Hare → Golden Eagle
whats a community
A community is all of the living organisms living in a particular area.
when does competition occur
Competition in ecosystems will occur between organisms when resources are in short supply.
what is an ecosystem
An ecosystem consists of all the organisms (the community) living in a particular habitat and the non-living components with which the organisms interact.
Describe the interactions of niches between organisms in the environment
A niche is the role an organism plays within a community.
A niche relates to the resource’s organisms require in the ecosystem, such as light and nutrient availability. It can also involve competition, predation and the conditions it can tolerate such as temperature.
what are animals in competition for
food
space
water availability
mates
what is intraspecific competition
Intraspecific competition occurs from individuals of the same species for all of the resources they require.
what is interspecific competition
Interspecific competition occurs from individuals of different species for one or a few of the resources they require.
what are plants in competition for
nutrients
water
space
light/sunlight
Compare interspecific and intraspecific competition
Intraspecific competition is more intense than interspecific competition because organisms are competing for more resources.
what is biotic factors
Biotic factors are living factors which can affect biodiversity in an area.
what is abiotic factors
Abiotic factors are non-living factors which can affect biodiversity in an area.
examples of abiotic factors
light intensity
soil moisture
pH
temperature
examples of biotic factors
competition for resources
disease
grazing
predation
light meter limitations and sources of error
accidental covering of the probe, must be taken at the same time of da
soil moisture limitations and sources of error
must be placed at the same depth in the ground at each site and wiped clean between readings
ph probe limitations and sources of error
must be placed at the same depth and wiped clean between readings
temperature limitations and sources of error
thermometer must be held in the same position/depth at every sample point, time must be allowed for the reading to be taken
animal sample technique
A pitfall trap is used to measure small invertebrates that live on the ground.
A pot with small holes in the bottom is placed in the ground with the top flush to ground level. It is covered and collected regularly.
pitfalll trap sources of error and solutions
A limitation/source of error of this technique is:
Some animals within the trap may eat other captives
Not enough samples taken
How to solve these issues:
Check traps regularly and record
Set up more traps within the sample site
plant sample technique
A quadrat is used to sample plants and animals that don’t move. It is a metal/plastic square of varying different sizes. The most common is 1m2.
quadrat sources of error
not enough samples taken within the sample site
deliberately ‘choosing’ good spots
Biotic antibiotic effects biodiversity
Both biotic and abiotic factors can increase or decrease biodiversity in an area and affect the distribution of organisms.
Human influences that impact biodiversity
air pollution
water pollution
habitat destruction by deforestation
desertification
overfishing
Describe an indicator species
An indicator species by their presence or absence will indicate environmental quality/levels of pollution in an area.
summary equation for photosynthesis
CO2+H20———————>glucose+O2
light energy
Describe the light reactions of photosynthesis
During the light reactions, light energy from the sun is trapped by chlorophyll in chloroplasts and is converted into chemical energy which is used to generate ATP.
Water is split to produce Hydrogen and Oxygen. Oxygen diffuses out of the cell.
Describe carbon fixation
A series of enzyme-controlled reactions, which use hydrogen and ATP (produced by the light reactions) are combined with carbon dioxide to produce sugar.
