Life On Earth Flashcards
Habitat
The place where an organism lives
Population
All the members of one species living in a habitat
Community
All the plants,animals and microorganisms living in a habitat
Species
A group of organisms that can be interbreed to produce fertile offspring
Producer
A green plant that uses sunlight to make its own food by photosynthesis
Consumer
An organism that cannot produce its own food, it gains energy by eating another organism
Herbivore
An organism that eats plant material only
Carnivore
An organism that eats animal material only
Omnivore
An organism that eats a mixture of plant and animal material
Predator
An animal which hunts and kills other animals for food
Prey
An animal which is hunted and killed for food by another animal
Biodiversity
The number, abundance and variety of species
Food chain
A diagram which shows the transfer of energy between organisms
Food web
A diagram which shows inter-connected food chains
Niche
Its the role that an organism plays within a community
Interspecific competition
Occurs amongst individuals of a different species
Intraspecific competition
Occurs amongst individuals of the same species
Abiotic
Term used to refer to a factor that relates directly to a non living feature of an ecosystem
Biome
Large region of the earth distinguished from others by its climate,flora,fauna
Biotic
Term used to refer to a factor that relates directly to some aspect in of living organisms in an ecosystem such as competition
Competition
Struggle for existence between members of a community caused by the limited supply of an essential resource
Ecosystem
Natural biological unit made up of living in non-living parts
Parasitism
Ecological where one organism benefits at the expense of another organism in the host
Pollution
General term for contamination of the environment
What are the two different types of sampling
Pitfall traps, Quadrat
What is a problem when using a pitfall trap
•If a leaf isnt covering the top meaning birds can eat insects
•If the cup isnt all the way in the soil insects cant climb in
What is a problem with a quadrat?
If a plant/flower is half in a square and you count some but not all.
How do you measure light, moisture and pH
•light meter
•moisture meter
•pH meter
What is a line transect
A transect line across a habitat or part of a habitat
What is the indicator species
A species that by its presence or absence shows the environmental quality/levels of pollution of an area
Abundance
Measure of the extent to which an organism occurs in an ecosystem
Key
Identifying organisms based on their characteristics using a series of paired statements
Distribution
Location or spread of a type of living organism in an ecosystem
Line transect
Method used to sample an ecosystem at intervals along a straight line
Pitfall trap
Open container buried to its rim in soil and used to catch animals active on the soil surface
Quadrat
Square shaped sampling unit of known area
Randomisation
Arrangement of sampled that lacks a pre-arranged pattern in order to eliminate bias
Replication
Procedure by which several samples are taken at each sampling sight to increase reliability of results
Sampling technique
Method of obtaining data based in samples that are sufficient in number to be representative of the population or ecosystem as a whole
Source of error
Limitation of a sampling technique that produces unreliable results
Pyramids of numbers
A pyramid of numbers shows the total number of food organisms at each stage in a good chain. (Not always pyramid shaped)
Pyramid of energy
The most realistic way of representing energy levels in a food chain. (Always has the shape of a true pyramid)
What are the two stages of photosynthesis
Photolysis (light dependent)
The carbon fixation stage (light independent)
Describe photolysis
Light-energy(moves to stage 2)-hydrogen(moves to stage 2)-oxygen(waste product/leaves plant)
Describe carbon fixation
Carbon dioxide-energy-hydrogen=glucose-starch(storage carb)-respiration-cellulose(structural carb)
What are the limiting factors
Carbon dioxide concentration, light intensity and temperature
Algal bloom
Result of rapid growth of population of simple water plants
Bioaccumulation
Increase in concentration of non-biodegradable chemical (such as DDT) in the cells of the organisms along a food chain
Biological control
Reduction of a pest population by the deliberate introduction of one of its natural enemies
Fertiliser
Substance rich in chemicals such as nitrate essential for healthy plant growth
Genetically modified (GM) crop
Domesticated plant that has been altered by genetic engineering to give greater food yield or resistance to pests.
Indicator species
Organisms whose presence shows the state of an environments health
Intensive farming
Form of agriculture which gives increased yield by growing crop monocultures and by ‘battery farming’ animals
Leaching
Loss of soluble chemicals from soil solution to a local waterway in rainwater run-off
Lichen
Simple plant which indicates the level of air pollution by sulfur dioxide gas
Monoculture
Vast cultivated population of one type of crop plant whose members are often genetically identical
Pesticide
General name for chemical used to kill pest species
Sulfur dioxide
Poisonous gas that harms living things and reduces biodiversity
Adaptation
inherited characteristic that makes an organism well suited to its environment and increases its chance of survival
Antibiotic resistant
Type of microorganism whose growth is not inhibited by chemicals such as penicillin
Evolution
Process involving natural selection that has transformed life on earth from its earliest beginnings to its present diverse state
Isolating mechanism
Barrier which prevents gene exchange between sub-populations
Mutagenic
Term describing an agent which increases the mutation rate
Mutation
Random change in the structure or composition of an organisms genetic material
Natural selection
Process by which individuals best adapted to the environment survive and pass on their genes on to succeeding generations
Selection pressure
Force on natural selection acting on the diverse numbers of a species to the advantage of some but not others
Selective advantage
Benefit gained by mutant organisms in an environment which suits them but not other members of the population
Species
Group of genetically similar organisms that produce fertile off spring and share the same basic anatomy and physiology
Variation
Differences due to inherited (and environmental) factors that exist between the members of a species
