Unti Of Life Flashcards
Name the two raw materials needed by plants in order to make food.
Water and carbon dioxide
Name the conditions needed for the process of photosynthesis take place e
Chlorophyll and light
Name the products made by the results of photosynthesis
Glucose and oxygen
What is the source of energy which powers the light reaction
Light energy
How is the energy captured
Absorbers by chlorophyll
What happens to the oxgen formed during stage 1
Realises into the atmosphere
Which two products of light reaction la are required for stage two
Hydrogen and atp
What does the letters stand for
Where does the carbon dioxide for stage two come from if the plant lives (a) on land and (b) in water
A - air
B- animals in the water
Where does the hydrogen come from to allow stage two to occur
From stage 1 ATP
Where does the energy come from to allow stage 2 to occur
From stage 1 ATP
What controls this carbon fixation of reaction
Enzyme
What are the stages of photosynthesis
Light reaction and carbon fixation
Describe the first stage of photosynthesis
Light reaction: the light energy from the sun is trapped by the chlorophyll in the chloroplast and is converted into chemical energy which is used to generate ATP. Water splits to produce hydrogen & oxygen. Oxygen diffuses from the cell
Describe the second stage of photosynthesis
Carbon fixation: a series of enzyme-controlled reactions which use hydrogen and ATP (Produced by the light reaction) with carbon dioxide to produce sugar
Complete the diagram (1) of photosynthesis on notes
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Complete the diagram (2) of photosynthesis on notes
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Look at the diagram in notes from increase of temperature. Explain what happens at point X
Rate of photosynthesis increases as temperature increases
Look at the disgrace effect the increasing temperature. Explain what’s happening at point Y
This is the optimum temperature of this type of plant. Rate of photosynthesis is fastest here
Look at the disgrace effect the increasing temperature. Explain what’s happening at point Z
Enzymes which controls photosynthesis are denatured
What can photosynthesis be limited by
Carbon dioxide
light intensity
temperature
Describe the 3 fates of glucose after its produces in photosynthesis
Starch - storage
For respiration
Cellulose ( structural )
What’s the definition of a limiting factor
A limiting factor is a factor while in short supply can slow or restrict the rate of photosynthesis
What is the definition of biodiversity
Total variety of amongst all living things on earth
What is the definition of a abiotic factor
Non living factors that can effect the distribution of organisms
What is the definition of a biotic factors
Living factors that can effect the distribution of organisms
Why is the definition of a community
A community - all of the animals and plants that are living in one area
What is the definition of a ecosystem
An ecosystem consists of all organisms living in a particular area and the non living components with which they interact
What is the definition of food chain
A sequence that shows the feeding relationships and the transfer of energy between organisms
What is the definition of food web
Food chains that are linked to show the complex feeling relation in a habitat
What is the definition of habitat
A habitat is the place where an organisms lives
What is the definition of omnivore
organisms that feeds on both animals and plants
What is the definition of a population
A population is a group of organimss of one species living in an area
What is the definition of a producer
Organism that produces their own food
What is the definition of a species
A species is a group of genetically similar organisms that can interbreed to produce fertile offspring
What is the definition of a niche
A niche is the role that an organism plays within a community
Example of a producer if
Grass—->grasshopper——> mouse —-> owl
Grass
Example of a consumer if
Grass—->grasshopper——> mouse —-> owl
Grasshopper
Mouse
Owl
What does a food chain represent
Represents a feeding relationship within the community
What’s the definitions of interspecific competition
Interspecfic competition= when individuals of different species require similar resources so competition occurs
What’s the definitions of intraspecific competition
Intraspecfic competition = while individual la of the same species require the same resources so competition occurs
What are abiotic factors
Moisture
Light intensity
Ph
Temperature
What are biotic factors
Competition for resources (e.g food and space )
Diseases
Predation
Grazing
What is a. Source of error for a light meter
A shadow may be cast on the light meter
How do you minimise error when measuring light intensity
Ensure that nobody is covering the light meter
What is a source of error of soul moisture
Moisture left on probe from previous reading
How do you minimise error when measuring soil moisture
Wipe the probe between such reading
How do you minimise error when measuring pH
Clean probe between each reading
What is a source of error for pH
Contamination from previous samples
What is a quadrant used to sample
Plants and slow moving animals
What should a quadrat be thrown randomly
To ensure the results are more reliable
Describe a possible source of error using quadrates and describe how it can be minimised
Ten quadrates may be too small a number of samples. To fix this we use a much larger number of quadrats. These could be studied repeating an experiment makes it more reliable
What is a pitfall trap used to sample
Invertebrates ( e.g wood lice )
Why should pitfall traps be levelled to the ground
It allows the ground animals to fall in
Describe a possible source of error using pitfall traps and describe how it can be minimised
Birdss may eat the trapped animals we can stop this by making sure the pitfalls trap is camouflaged
Describe a possible source of error using pitfall traps and describe how it can be minimised
Birdss may eat the trapped animals we can stop this by making sure the pitfalls trap is camouflaged
What is a indicator species
Organisms that indicate levels of pollution or environmental quality by their presence absence or abundance in the environent
What examples are there of indicator species
Daphina
Lincheaa
How is energy lost while moving in the food chain
Heat movement and undigested material
What is energy used for
Growth
The definition of pyramid of numbers
Gives information about the total numbers of organisms in each level of the food chain
What type of organisms do we find First at the beginning of a food chain
Producers
What is gained by the predator that eats the prey
Energy
What do the arrows in a good chain represent
The energy flow
The definition of pyramids of energy
Gives information about the energy content of all the organisms in each level of the food chain
What’s the definition of Algal bloom
Lots of algae which covers surface water ( block the light)
What’s the definition of bioaccumulation
When toxic levels build up within a food chains
What’s the definition of biological control
Uses natural predators to get rid of pests on crops
What’s the definition of fertilisers
Chemical fertilisers are added to the soil to increase the number of plants which can be grown. Provides plants with nitrates
What’s the definition of nitrates
Nitrates are used to produce amino acid while are synthesised into plant proteins
What’s the definition of genetically modified
Changes dna of organisms
What’s the definition of pesticides
Pesticides are chemical used to control organisms that can damage crops. Farmers spray crops with this to increase crop Felid
What’s the definition of food production
Increasing human population requires an increase food yield this can involve using:
Fertiliser
Pesticides
What’s the definition of crop yield
Increase plants
Describe the 5 steps involved in the development of an algae bloom
- Fertilisers run into fresh water and add extra nitrates
- Numbers of algae increase CNA cause a bloom which reduces the light that can pass into water
- Aquatic plants die due to a lack of light
- Dead plants become a food source for bacteria so they will increase in number
- Bacteria uses an amount of oxygen meaning there is less for other organisms which will then die
The chemical added to the soul by the gardener contained nitrates give the general name for this type of chemical
Fertiliser
If 50,000 hectored of land available in Scotland to grow crops, what area of land was used for barley (55%) production
27,500
State one problem associated with spraying pesticides onto crop plants
Bioaccumulation will occur causing predators to be endangered. Resulting to possible extinction
What happens when certain pesticides pass along a food chain
The toxicity increases and can reach to lethal levels
Fill in the blanks
Many pesticides are _____ chemicals that ____ break in the environment
Toxic
Don’t
What does biological control usually involve
The use of a predator
What animals are used for biological control
Use of lady birds to eat aploids
Describe the negative impact fertilisers can have on our environment
Leaching/runoff algae bloom starts to form which blocks sunlight and causes oxygen levels to decrease so fish suffocate the balance in species in the community become unbalanced
What’s of the following happens to the algae population, Bacterial population and oxygen concentration. When as a result of fertiliser going an leaching into a fresh water
Algae population = increases
Oxygen concentration = decreases
Bacterial population =increase
What does a food chain represent
A sequence that shows feeing relationships within a community
What does the arrows represent in a food chain mean
The transfer of energy
Definition the term mutation and state the three types of mutation
A mutation is a random change to genetic material. Mutations may be neutral. Advantageous or disadvantageous
Describe what impact certain environmental factors may have on mutations and give an example
Environmental factors ( e.g radiation) may increase the rate of mutation
Des five how mutations may lead to organisms becoming better adapted to their environment
If a mutations produces a new allele that increases the change of an organisms survival
When does natural selection occur
When there are selection pressures
Fill in the gaps about natural selection.
The best adapted individuals in a population _____ to ______, passing on the favourable alleles that confer the selective advantage
Survive
Reproduce
What is a formation of a new species
Speciation
When does speciation occur
It occurs when a population becomes isolated from other populations of the same species and mutation occurs
Isolation barriers can be:
Geographical - rivers, mountains
Ecological - pH, temperature, humidity
Behavioural - breeding cycles out of rhythm
What are the stages of speciation
- Isolation:
Populations becomes isolated by an isolation barrier - Mutation:
Different mutations occur in each sub-population - Natural selection:
Natural selection selects for different mutations in each group, due to different selection pressures - New species:
Each sub-population evolves until they become so genetically different from each other they are two different species
Look on the diagram on notes evaluation of species
How do we find out a percentage increase
Percentage increase = difference/orignial x 100
How do we find out percentage decrease
Difference/no. Before difference x 100
