Edexcel Biology Unit 4 A Level
exam qs & as best rated a
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Fewer prey eaten by the population
Therefore, prey increase in number
Less competition for food from the population
Predator of the population might decrease, eat other prey or migrate - Answer
Suggest how other animals are affected by a fall in another population
Factors involving organisms and living things - Answer Define biotic factors
Factors that are physical, chemical or nonliving - Answer Define abiotic factors
Several readings
,Use of random quadrat positions
Random number calculator
Known area of quadrat
Number of individuals in each quadrat counted
For mean density: total number of each species divided by total area sampled -
Answer Species density quadrat experiment
Light intensity, temperature, pH - Answer Examples of abiotic factors
Predators, food availability, disease, competition - Answer Examples of biotic
factors
Change in DNA
A deletion/addition/duplication/substitution of bases - Answer Explain gene
mutation
A sequence of changes in a community
Over a period of time - Answer Define Succession
Final stage
Stable - Answer Define Climax community
Thylakoids made of membranes
Arranged as grana
Contain chlorophyll
Arranged as photosystems
, Membranes contain ATPase
Electron carriers associated with thylakoid membranes - Answer Describe the
structures in a chloroplast involved in the light-dependent reactions
Crops grown all year round
Plants photosynthesise 24 hours a day
Less physical damage due to weather and animals
Pest control easier
Control of temperature/water supply - Answer Advantages of growing crops in
glasshouses with artificial light instead of open fields
Greenhouse gases
Trap heat and infra red
Reflected from Earth's surface
Mean temperature of earth's surface increases - Answer Effects of carbon dioxide
and methane on Earth's temperature
Polymerase - Answer Enzyme used to amplify DNA
Gel electrophoresis - Answer Process used to separate DNA fragments
1. All of the bands in the sample must match
2. DNA profiling assumes every individual's DNA is unique
exam qs & as best rated a
+.
Fewer prey eaten by the population
Therefore, prey increase in number
Less competition for food from the population
Predator of the population might decrease, eat other prey or migrate - Answer
Suggest how other animals are affected by a fall in another population
Factors involving organisms and living things - Answer Define biotic factors
Factors that are physical, chemical or nonliving - Answer Define abiotic factors
Several readings
,Use of random quadrat positions
Random number calculator
Known area of quadrat
Number of individuals in each quadrat counted
For mean density: total number of each species divided by total area sampled -
Answer Species density quadrat experiment
Light intensity, temperature, pH - Answer Examples of abiotic factors
Predators, food availability, disease, competition - Answer Examples of biotic
factors
Change in DNA
A deletion/addition/duplication/substitution of bases - Answer Explain gene
mutation
A sequence of changes in a community
Over a period of time - Answer Define Succession
Final stage
Stable - Answer Define Climax community
Thylakoids made of membranes
Arranged as grana
Contain chlorophyll
Arranged as photosystems
, Membranes contain ATPase
Electron carriers associated with thylakoid membranes - Answer Describe the
structures in a chloroplast involved in the light-dependent reactions
Crops grown all year round
Plants photosynthesise 24 hours a day
Less physical damage due to weather and animals
Pest control easier
Control of temperature/water supply - Answer Advantages of growing crops in
glasshouses with artificial light instead of open fields
Greenhouse gases
Trap heat and infra red
Reflected from Earth's surface
Mean temperature of earth's surface increases - Answer Effects of carbon dioxide
and methane on Earth's temperature
Polymerase - Answer Enzyme used to amplify DNA
Gel electrophoresis - Answer Process used to separate DNA fragments
1. All of the bands in the sample must match
2. DNA profiling assumes every individual's DNA is unique
