Unit 3 Flashcards
Species
A group of living things that can breed to produce fertile offspring
Biodiversity
The variety of living things in a defined area
Population
All the organisms of the same species living in the same area
Ecosystem
All the organisms living in an environment and the non living components that the organisms react which
Habitat
The place where an organism lives
Producers
A plant at the beginning of a food chain
Consumer
An animal in a food chain that eats something else
Herbivore
Only eats plants
Carnivore
An organism that only eats animal matter
Omnivore
An organisms that eats both plants an animals
Predator
An organism Hunts prey
Prey
An organism that’s hunted by predators
Community
All the organisms in an ecosystem
Niche
The role of an organism in a community
Intra specific competition
When individuals of the same species compete for all the same resources
More intense than inter specific
Inter specific competition
When individuals of different species compete for some of the same resources
Non living components of an eco system
Light
Water
Rock
Soil
Examples of Living components
Animals
Plants
Bacteria
What do plants compete for
Light
Water
Space
What do animals compete for
Food
Water
Shelter
Mates
Arrows in a food chain represent ?
The flow of energy
Biotic factor
A living factor that influences an ecosystem
Abiotic factors
A non living factor that influences an ecosystem
Quadrat
Equipment used to estimate the number of plants in a given area
Pitfall trap
Equipment used to count an estimate the number of small animals in a given location
Paired statement key
A set of paired questions that allow living things to be identified
Indicator species
Species that determine environmental quality/pollution by their presence and absence
Light intensity
The amount of light available
Soil moisture
The water content of soil
Name abiotic factors
Light intensity
Moisture
PH
Temperature
Name biotic factors that influence an ecosystem
Competition
Disease
Food availability
Grazing
Predation
Factors that can increase bio diversity
Increased moisture levels
Warm temperature
Good food availability
Factors that can decrease biodiversity
Extreme temperature
Overgrazing
Too many predators
what do you use to measure light intensity
Light meter
How to measure soil moisture
Moisture meter
How to measure soil PH
PH meter
Sources of error with a light meter and how to prevent
User could cast a shadow over the meter
Prevent this by standing to one side to prevent casting a shadow
Sources of error with moisture/PH meter and how to prevent
Soil left on probe from previous readings
Prevent this by wiping the probe dry between readings
Sources of error with quadrats
Human judgment- struggling to decide if a plant is inside or outside the quadrant
Prevent by using basic rules to keep counting consistent
Sources of error with pitfall traps and how to prevent
Animals may escape or get eaten
Prevent by covering the trap and keeping it hidden from predators.
Photosynthesis
A two stage process in plants to make sugar from water and carbon dioxide using light energy
What is the first stage of photosynthesis called
Light reactions
Chlorophyll
A chemical found in chloroplast that is able to trap light energy
what is the second stage of photosynthesis called
Carbon fixation
What is sugar converted into for storage
Starch
What is sugar converted into for structural uses
Cellulose
What is a limiting factor
A factor or substance that prevents a chemical reaction from happening quick
What happens during step one (light reactions) of photosynthesis
-Light energy from the sun is trapped by the chlorophyll
-Some light energy is converted into chemical energy
-the remaining light energy is used to split water into hydrogen and oxygen
Oxygen diffuses out the cell
What happens during stage 2 (carbon fixation) of photosynthesis
-The ATP and hydrogen generated from stage one is combined with carbon dioxide from the air
-They are then converted into sugar during a series of enzyme controlled reactions
What are the 3 uses of sugar made by photosynthesis
Respiration to produce ATP
Storage as starch
Cellulose for cell wall
What is a pyramid of numbers
A diagram of the total numbers of organisms at each stage of a food chain
Pyramid of energy
A diagram of the total energy contained within each stage of the food chain
How to tell the difference between pyramid of energy and pyramid of numbers
Pyramids of numbers can be irregularly shaped
Pyramids of energy is always pyramid shaped
Three ways energy can be lost along a food chain
Heat
Movement
Undigested materials
Food yield
The amount of food grown from crops
What is a fertiliser
Mixture of chemicals used to increase crop yield
Nitrates
A type of chemical important for amino acids and protein formation
Pesticides
Chemicals that kill animals or weeds that harm crops
Amino acids
The building blocks of proteins
Leaching
The process of fertilisers being washed from the fields into water supplies
Algal bloom
A sudden increase in algal population
Genetically modified
A living organism that has had new genes added to it artificially
Toxicity
A measure of the harmfulness of a chemical to living things
Biological control
Using living organisms to control pests. For example ladybirds to eat greenfly
How to increase food yield
Use fertilisers
Use GM crops
How to prevent pests from damaging crops
Pesticides
GMcrops
Biological control
Disadvantage of fertilisers
They can leach into fresh water
Disadvantage of pesticides
Bioaccumulation in food chains.
Disadvantage of GM crops C
Expensive
Disadvantage of biological control
Difficult to manage
Steps of fertilisation
1.Fertilisers are added
To soil to increase the nitrate content of the soil
- Nitrates dissolved in water are absorbed into plants
- The nitrates are used to make amino acids which combine to make plant protein
4.animals eat plants or other animals to obtain amino acids for protein synthesis
Steps of leaching
1.fertilisers leach into water
- There is an algal bloom in the water
3.algal blooms block the light, which kills the plants
- Dead plants feed bacteria which causes an huge increase in bacteria
- The bacteria uses a large amount of oxygen which reduces oxygen availability for other organisms like fish
Bioaccumulation
Chemicals in pesticides can accumulate in the bodies of organisms and gets passed along the food chain. The toxicity increases as it gets passed along the food chain which can be lethal
Mutation
A random change to genetic material
Alleles
Different versions of the same gene (brown eyes and blue eyes for example)
Variation
The differences within a population
Natural selection
The process by which evolution occurs
Speciation
The process that results in a new species
Isolation barrier
A geographical, behaviour or ecological mean that separates two populations
Selection pressure
A change in the environment for a living things eg a new predator in the ecosystem
Adaption
An inherited characteristic that makes an organism well suited for survival in its environment
Factors that can increase mutation rate
Processed food
Some chemicals
Radiation
Why is variation important
It’s important as it allows a population to evolve to suit any new selection pressures
Steps of natural selection
- Species produce more offspring than the environment can sustain
- The best adapted individuals in a population survive
- The survivors reproduce and pass on favourable alleles with the selective advantage
4.the favourable alleles increase in frequency within the population
Steps of speciation
- Part of a population becomes isolated by an isolation barrier.
- Over a long period of time, different mutations occur in each sub population
3.there will be different selection pressures acting in the two groups.
4.Each sub population evolves until they become so genetically different that they are two different species
The 3 types of isolation barriers
Geographical
Ecological
Behavioural
Examples of geographical barriers
Rivers
mountains
Oceans
Examples of ecological barriers
PH,
Different habitats
Salinity
Example of behaviour barrier
Different mating behaviour
