Whole Unit Key Terms and Definitions Flashcards
What occurs during competition?
Occurs when the resources that two organisms or species are in short supply.
What is survival of the fittest?
Another term used to describe natural selection.
Define natural selection.
The process by which favourable alleles are passed down to offspring over generations.
Biodiversity
The range of different species present in an ecosystem. The higher the biodiversity, the more species present
What is the definition of evolution?
The gradual change in the inherited traits within a population over time.
What is speciation?
The formation of new species as a result of the isolation of groups.
Producer
An organism that makes its own food by photosynthesis (i.e. a green plant)
What do bacteria feed on?
Dead plants and dead algae.
What are isolation barriers?
Geographical, ecological or behavioural factors that isolate populations.
What is a community in ecological terms?
All the organisms living in an area, i.e., all the different plants and animals.
What is leaching?
Excess nitrates are washed out of the soil into fresh water ecosystems.
Define distribution in ecology.
The spread of living organisms in an ecosystem.
Define adaptation.
An inherited characteristic that makes an organism well suited to survival in its environment.
Define niche.
The role an organism plays within its community.
Omnivore
A consumer that eats both plant and animal material (i.e. human). Omnivores can be primary or secondary consumers
What is an organism?
Any living thing, animal, plant, or micro-organism.
Food Chain
Shows the simple feeding relationship between organisms
What is a mutation?
A random change to an organism’s genetic material.
Define population.
All the members of the same species living in a habitat.
What causes irregular shapes in pyramids of numbers?
Differences in body size.
Carnivore
A consumer that eats animal material only (i.e. lion). Carnivores are secondary consumers
Abiotic Factor
The non-living factors influencing an ecosystem (i.e. temperature)
What is inter-specific competition?
Occurs when individuals of different species require one or a few of the same limited resources.
What is a pH meter used for?
Apparatus used to measure different abiotic factors.
What form of energy is required by a producer?
Light.
What are genetically modified crops used for?
To reduce the use of fertilizers and as an alternative to the use of pesticides.
Ecosystem
All the organisms (community) living in a habitat and the non-living factors (abiotic) which the organisms interact
Herbivore
A consumer that only eats plant material (i.e. sheep). Herbivores are primary consumers
Define alleles.
Different forms of the same gene.
What are nitrates used for by plants?
To produce amino acids which are used to make plant proteins.
What are pesticides used for?
Used to kill plants and animals which reduce crop yield.
What accounts for the majority of energy lost in a food chain?
- Heat
- Movement
- Undigested material
Prey
The animal which is hunted and eaten by the predator for food
What is a quadrat?
A square grid of known area used in sampling to determine the abundance and distribution of organisms.
What is an ecosystem?
All the organisms living in a particular habitat and the non-living components with which the organisms interact.
What is a fertilizer?
Added to the soil to increase the nitrate content which increases crop yield.
Define pyramid of numbers.
A diagram that shows the relative numbers of organisms at each stage in a food chain.
What does sampling involve in ecology?
Taking a sample of part of the area rather than the whole area to estimate the variety and number of organisms present.
Define abiotic factor.
A non-living (physical) factor which can influence where organisms can live.
Define species.
A group of organisms that can interbreed and produce fertile offspring.
What is a herbivore?
A consumer/organism that only eats plant material.
What is energy loss in a food chain?
The majority of the energy is lost during transfers from one level to the next.
Define pyramid of energy.
A diagram that shows the relative quantities of energy at each stage in a food chain.
What is an indicator species?
Species whose presence or absence in an environment provides an indication of environmental quality.
Population
All the organisms of one species living in an area
Species
A group of organisms which can interbreed and produce fertile offspring
Define habitat.
The place where an organism lives.
Consumer
An organism that eats a plant or animal to gain energy
What is a food chain?
Shows the flow of energy in a simple feeding relationship from a producer through various species to the top carnivore.
What are resources in an ecological context?
All the things needed by an organism to survive.
How are proteins synthesized?
From amino acids.
Biotic Factor
The living factors influencing an ecosystem (i.e. predation)
What does a food web represent?
A complex diagram consisting of many food chains linked together showing more complex feeding relationships in an ecosystem.
What is biodiversity?
The variety of organisms found in a particular area.
The higher the biodiversity, the more species present.
What is a pitfall trap used for?
Used to sample invertebrates living on the ground.
Define an omnivore.
An organism which has to eat plants or other animals to gain energy.
What are new alleles produced by?
Mutations.
What is overproduction in ecology?
A species produces more offspring than the environment can sustain.
What does a predator do?
An animal which hunts, kills, and feeds on other animals.
What is intra-specific competition?
Occurs when individuals of the same species require all of the same limited resources.
What environmental factor can increase the rate of mutation?
Radiation.
Community
All the organisms living in an area (i.e. all the plants and animals in a field)
What is a neutral mutation?
A random change in genetic material that has no effect on the organism’s survival.
What is replication in experiments?
Where consistent values in repeats of experiments are obtained.
What is a transect line?
A line along a sampled area upon which quadrats are placed at regular intervals.
What is a biotic factor?
A factor caused by living organisms in an ecosystem.
Food web
Consists of many food chains linked together showing the more complex feeding relationship in an ecosystem
What increases crop yield?
Using fertilizers and pesticides to meet the increase in food production required.
What is biological control?
The use of natural predators, disease, or parasites to limit the population of pest species.
Name examples of abiotic factors.
- Temperature
- Light intensity
- Moisture
- pH
Define a carnivore.
An organism/consumer that only eats other animals.
Predator
An animal which hunts, kills and eats another animal (it’s prey)
What is a producer?
An organism which makes its own food by photosynthesis.
What is a paired-statement key?
Used to identify unknown plants or animals found when sampling.
What is growth in the context of energy transfer?
Only a very small quantity of energy is used for growth and is available at the next level in a food chain.
What does variation within a population allow?
Makes it possible for the population to evolve over time.
What is the form of energy contained in food?
Chemical.
What is a selective advantage?
A favourable characteristic which gives an organism an increased chance of survival.
Define bioaccumulation.
The build-up of toxic substances in living organisms.
What is selection pressure?
A factor that affects a population resulting in the death of some individuals.
Habitat
A place where an organism lives (i.e. the sea)
What causes algal bloom?
Large increase in the population of microscopic algae caused by the addition of extra nitrates.
Niche
The role an organism has in its ecosystem (i.e. what it eats, what eats it, its habitat etc.)
What is a representative sample?
Samples are taken at random.
What is prey?
The animal which is hunted and eaten by a predator for food.
What is an advantageous mutation?
A random change in genetic material that confers an advantage to the organism’s survival.
What is a disadvantageous mutation?
A random change in genetic material that confers a disadvantage to the organism’s survival.
Name examples of biotic factors.
- Predation
- Disease
- Competition for resources
- Grazing
- Food availability
What is a food chain?
Describes the feeding relationships between organisms and the transfer of energy between them.
What is photosynthesis?
A two-stage process that converts light energy from the sun into chemical energy in sugar.
What is a producer?
An organism which makes its own food by photosynthesis (i.e. a green plant).
What are light reactions?
The first stage of photosynthesis in which water is split and ATP is generated.
What is chlorophyll?
Traps the light energy from the sun required for the first stage of photosynthesis.
What is a chloroplast?
Cell organelle which contains chlorophyll and is the site of photosynthesis.
What is ATP?
Energy rich molecule synthesised during the light reactions which is required for carbon fixation.
What is water’s role in photosynthesis?
A raw material required for the first stage of photosynthesis.
What is hydrogen in the context of photosynthesis?
Produced by splitting water and combines with carbon dioxide to produce sugar.
What is oxygen in photosynthesis?
A by-product of water splitting which diffuses out of the leaf.
What is carbon fixation?
A series of enzyme controlled reactions which use hydrogen and ATP (produced during the light reactions) with carbon dioxide to produce sugar.
What is sugar in photosynthesis?
A product of photosynthesis that is available as a source of chemical energy for respiration or can be converted to other substances.
What is cellulose?
The sugar produced by photosynthesis can be converted into this structural carbohydrate which is used to make plant cell walls.
What is starch?
The sugar produced by photosynthesis can be converted into this storage carbohydrate.
What are limiting factors?
A factor which, if in short supply, limits or reduces the rate of photosynthesis.
What is the limiting factor on a warm, sunny day?
Carbon dioxide concentration.
What is the limiting factor on a cloudy day?
Light intensity.
What is the limiting factor on a sunny day in winter?
Temperature.
How does growth relate to photosynthesis?
Growth is reduced if the rate of photosynthesis is limited. Is at a maximum when there are no limiting factors.
What role do enzymes play in carbon fixation?
Control the series of reactions that take place during carbon fixation.
