AQA GCSE Biology Paper 2
methods must be found to feed all people on Earth - ANS-Sustainable
\2 pros & 2 cons of GM crops - ANS-+increased yield=more food
+already being grown, not problematic
-worries on human health/safety/allergies
-long term effects-unplanned problems that could could pass on to future generations
\A person who is heterozygous for brown eyes (Bb) has children with a person who has blue
eyes (bb). What percentage of their children will have blue eyes? - ANS-50%
\A protein-rich food suitable for vegetarians - ANS-Mycoproten
\Abiotic factors - ANS-Non-living factors
\Adaptations - ANS-Features which enable an organism to survive in the conditions in which
they normally live
\Adaptations may be... - ANS-...structural, functional or behavioural
\Apex predators - ANS-Carnivores with no predators
\Biodiversity - ANS-The variety of all the different species of organisms on earth, or within an
ecosystem
\Biological factors which are threatening food security - ANS-1. Increasing birth rate - in
some countries
2. Changing diets in developed countries - scarce food resources transported around the
world
3. New pests and pathogens that affect arming
4. Environmental changes that affect food production - e.g. widespread famine in some
countries if rains fail
5. Cost of agricultural inputs
6. Conflicts -have arisen in some parts of the world which affect the availability of water or
food
\Biotic - ANS-Living factors
\Cause of cystic fibrosis? - ANS-Caused by a Recessive Allele -'f'
Alleles-'Ff'-unaffected but is a carrier
Alleles- 'ff'- has cystic fibrosis
\Changes as a result of human interaction - ANS-1. Global warming and climate change -
nwo working to maintain rainforest
2. Acid rain - now reducing water pollution and monitoring pH
3. Pollution from farms and factories - now conservation measures such as replanting
hedgerows and woodlands, resitrcung access to sites of special scientific interest
\Compare and Contrast the endocrine (hormone) system and the nervous system. -
ANS-Nervous is faster acting than the endocrine system.
Hormones have longer lasting effects compared to electrical impulses. Nerves act on a very
specific area whereas hormones act more general.
\Competition - ANS-The process by which living organisms compete with each other for
limited resources
\Define accommodation. - ANS-Where the eye focuses light on the retina by changing the
shape of the lens.
,\Describe an experiment to investigate the effect of temperature on the rate of decay of fresh
milk using pH. - ANS-1. Full fat milk, phenolphthalein indicator, and alkaline solution (eg
sodium carbonate) in several tubes - this will be pink
2. Test tubes of lipase
3. Put test tubes in water baths of different temperatures - do NOT mix yet
4. When lipase and milk solution are same temperature, combine
5. Measure the time it takes for milk solution to turn colourless; the acid formed from
digestion of fats has turned the solution acidic
6. Repeat 3 times for each temperature and calculate mean
\Describe global warming - ANS-1. CO2 and methane contribute to the greenhouse effect -
they absorb some of the Sun's energy which is reflected off the earth
2. However now levels of carbon dioxide and methane in the atmosphere are increasing,
and contribute to 'global warming'
\Describe how animals can be cloned by adult cell cloning. [6] - ANS-The nucleus is
removed from an unfertilised egg.[1] A complete set of adult chromosomes from an adult
body cell is inserted into the egg. [1] The egg cell is then stimulated to divide to form an
embryo by being given an electric shock.[1] The embryo is then implanted into an adult
female [1] where it develops into a clone of the original adult body cell.
\Describe how you could clone a plant. (Cuttings) - ANS-Take a cutting from good parent
plants. Dip into rooting powder and plant. Can produce plants quickly and cheaply.
\Describe how you could clone a plant. (Tissue Culture) - ANS-Tissue culture- A few plant
cells are put in a growth medium with hormones and they grow into new plants. Plants can
be made quickly and cheaply in very little space.
\Describe Jean Baptiste Lamarck's theory. - ANS-Theory of Acquired characteristics. E.g. if a
giraffe stretched it's neck to reach tall branches over time the neck would get longer.
\Describe programmes put in place to reduce the negative effects of humans on ecosystems
and biodiversity - ANS-1. Breeding programmes for endangered species
2. Protection and regeneration of rare habitats
3. Reintroduction of field margins and hedgerows in agricultural areas where farmers grow
only one type of crop
4. Reduction of deforestation and CO2 emissions by some governments
5. Recycling resources rather than dumping waste in landfill
\Describe some of the biological consequences of global warming (4) - ANS-1. Loss of
habitats - due to rising sea levels
2. Changes in distribution - as temperatures and rain patterns change
3. Changes in migration patterns - as climates become hotter or colder
4. Reduced biodiversity - some animals will be able to survive as the climate changes eg
polar bears
\Describe speciation. - ANS-Speciation-over time, a phenotype of organisms will change so
much due to NATURAL SELECTION that a new species is formed.
\Describe the 4 trophic levels - ANS-Level 1. Producers - plants and algae make their own
food
Level 2. Primary consumers - herbivores eat plants/algae
Level 3. Secondary consumers - carnivores eat herbivores
Level 4. Secondary consumers - carnivores eat other carnivores
\Describe the carbon cycle - ANS-
\Describe the nutrient cycle (decay) (6) - ANS-1. Decay starts after death of organism
2. Detritus feeders eat the deceased body and produce waste
, 3. Decomposers digest everything
4. Decomposers multiply rapidly
5. Waste from decomposers inluding water, CO2 and mineral ions are used by plants to
grow
6. Plants take up mineral ions via roots to make proteins and chemicals in their cells
\Describe the stages in a reflex arc. - ANS-Stimulus->Receptor->sensory neurone->CNS
(relay neurone) -> motor neurone -> effector -> response
\Describe the structure of food chains, giving examples. (3) - ANS-1. All food chains begin
with a producer which synthesises molecules e.g. green plants, algae, which make glucose
by photosynthesis
2. Primary consumers eat producers
3. In turn these may be eaten by secondary and then tertiary consumers
\Describe the water cycle - ANS-1. Evaporation: water evaporates from the surface of land
and bodies of water
2. Transpiration: loss of water vapour from plants directly into the atmosphere
3. Respiration: loss of water vapour from animals directly into the atmosphere
4. Condensation: it rises into the air and condenses to form clouds
5. Precipitation: water droplets in clouds get heavier and fall as rain, snow or hail
\Detritivores - ANS-Detritivores/detritus feeders e.g. maggots and flies feed on dead, rotting
material. They break up the dead organism into smaller pieces, increasing the surface area
for digestion by microorganisms.
\Eaxmple of extremophiles - ANS-bacteria living in deep sea vents (at very high pressure, no
light, acid pH)
\Embryonic screening 3 pros/3 cons - ANS-Pros
1-helps to stop suffering
2-There are laws to stop it going too far-parents can't select sex of baby.
3-Treatment for genetic disorders costs NHS/tax payers money
Cons
1-implies people with genetic disorders are undesirable, leads to prejudice.
2-Screening is Expensive.
3-Could lead to designer babies e.g. parents want a blonde eyed, blonde haired boy.
\Environmental changes affect... - ANS-...the distribution of species in an ecosystem
\Ethical objections to modern intensive farming methods - ANS-1. Intensively farmed animals
suffer in uncomfortable conditions
2. They are not kept in their natural habitat
3. Furthermore intensive farming is not necessarily successful as studies show contented
animals gain biomass faster
\Evaluate the benefits and risks of procedures carried out on the brain and the nervous
system. - ANS-+ve- Can lead to the treatment for disorders of the nervous system
-ve- The brain is complex and delicate. The treatment of brain damage is difficult. It also
carries risks such as physical damage or increased problems with brain damage e.g.
speech.
NB: ADD A CONCLUSION.
\Example of a pathogen affecting food security - ANS-'Blue tongue' disease carried by
midges spreading to sheep and cattle in the UK from Europe
\Examples of behavioural adaptations - ANS-Basking, migration, tool use - e.g. birds
migrate, nocturnal to avoid heat of day
methods must be found to feed all people on Earth - ANS-Sustainable
\2 pros & 2 cons of GM crops - ANS-+increased yield=more food
+already being grown, not problematic
-worries on human health/safety/allergies
-long term effects-unplanned problems that could could pass on to future generations
\A person who is heterozygous for brown eyes (Bb) has children with a person who has blue
eyes (bb). What percentage of their children will have blue eyes? - ANS-50%
\A protein-rich food suitable for vegetarians - ANS-Mycoproten
\Abiotic factors - ANS-Non-living factors
\Adaptations - ANS-Features which enable an organism to survive in the conditions in which
they normally live
\Adaptations may be... - ANS-...structural, functional or behavioural
\Apex predators - ANS-Carnivores with no predators
\Biodiversity - ANS-The variety of all the different species of organisms on earth, or within an
ecosystem
\Biological factors which are threatening food security - ANS-1. Increasing birth rate - in
some countries
2. Changing diets in developed countries - scarce food resources transported around the
world
3. New pests and pathogens that affect arming
4. Environmental changes that affect food production - e.g. widespread famine in some
countries if rains fail
5. Cost of agricultural inputs
6. Conflicts -have arisen in some parts of the world which affect the availability of water or
food
\Biotic - ANS-Living factors
\Cause of cystic fibrosis? - ANS-Caused by a Recessive Allele -'f'
Alleles-'Ff'-unaffected but is a carrier
Alleles- 'ff'- has cystic fibrosis
\Changes as a result of human interaction - ANS-1. Global warming and climate change -
nwo working to maintain rainforest
2. Acid rain - now reducing water pollution and monitoring pH
3. Pollution from farms and factories - now conservation measures such as replanting
hedgerows and woodlands, resitrcung access to sites of special scientific interest
\Compare and Contrast the endocrine (hormone) system and the nervous system. -
ANS-Nervous is faster acting than the endocrine system.
Hormones have longer lasting effects compared to electrical impulses. Nerves act on a very
specific area whereas hormones act more general.
\Competition - ANS-The process by which living organisms compete with each other for
limited resources
\Define accommodation. - ANS-Where the eye focuses light on the retina by changing the
shape of the lens.
,\Describe an experiment to investigate the effect of temperature on the rate of decay of fresh
milk using pH. - ANS-1. Full fat milk, phenolphthalein indicator, and alkaline solution (eg
sodium carbonate) in several tubes - this will be pink
2. Test tubes of lipase
3. Put test tubes in water baths of different temperatures - do NOT mix yet
4. When lipase and milk solution are same temperature, combine
5. Measure the time it takes for milk solution to turn colourless; the acid formed from
digestion of fats has turned the solution acidic
6. Repeat 3 times for each temperature and calculate mean
\Describe global warming - ANS-1. CO2 and methane contribute to the greenhouse effect -
they absorb some of the Sun's energy which is reflected off the earth
2. However now levels of carbon dioxide and methane in the atmosphere are increasing,
and contribute to 'global warming'
\Describe how animals can be cloned by adult cell cloning. [6] - ANS-The nucleus is
removed from an unfertilised egg.[1] A complete set of adult chromosomes from an adult
body cell is inserted into the egg. [1] The egg cell is then stimulated to divide to form an
embryo by being given an electric shock.[1] The embryo is then implanted into an adult
female [1] where it develops into a clone of the original adult body cell.
\Describe how you could clone a plant. (Cuttings) - ANS-Take a cutting from good parent
plants. Dip into rooting powder and plant. Can produce plants quickly and cheaply.
\Describe how you could clone a plant. (Tissue Culture) - ANS-Tissue culture- A few plant
cells are put in a growth medium with hormones and they grow into new plants. Plants can
be made quickly and cheaply in very little space.
\Describe Jean Baptiste Lamarck's theory. - ANS-Theory of Acquired characteristics. E.g. if a
giraffe stretched it's neck to reach tall branches over time the neck would get longer.
\Describe programmes put in place to reduce the negative effects of humans on ecosystems
and biodiversity - ANS-1. Breeding programmes for endangered species
2. Protection and regeneration of rare habitats
3. Reintroduction of field margins and hedgerows in agricultural areas where farmers grow
only one type of crop
4. Reduction of deforestation and CO2 emissions by some governments
5. Recycling resources rather than dumping waste in landfill
\Describe some of the biological consequences of global warming (4) - ANS-1. Loss of
habitats - due to rising sea levels
2. Changes in distribution - as temperatures and rain patterns change
3. Changes in migration patterns - as climates become hotter or colder
4. Reduced biodiversity - some animals will be able to survive as the climate changes eg
polar bears
\Describe speciation. - ANS-Speciation-over time, a phenotype of organisms will change so
much due to NATURAL SELECTION that a new species is formed.
\Describe the 4 trophic levels - ANS-Level 1. Producers - plants and algae make their own
food
Level 2. Primary consumers - herbivores eat plants/algae
Level 3. Secondary consumers - carnivores eat herbivores
Level 4. Secondary consumers - carnivores eat other carnivores
\Describe the carbon cycle - ANS-
\Describe the nutrient cycle (decay) (6) - ANS-1. Decay starts after death of organism
2. Detritus feeders eat the deceased body and produce waste
, 3. Decomposers digest everything
4. Decomposers multiply rapidly
5. Waste from decomposers inluding water, CO2 and mineral ions are used by plants to
grow
6. Plants take up mineral ions via roots to make proteins and chemicals in their cells
\Describe the stages in a reflex arc. - ANS-Stimulus->Receptor->sensory neurone->CNS
(relay neurone) -> motor neurone -> effector -> response
\Describe the structure of food chains, giving examples. (3) - ANS-1. All food chains begin
with a producer which synthesises molecules e.g. green plants, algae, which make glucose
by photosynthesis
2. Primary consumers eat producers
3. In turn these may be eaten by secondary and then tertiary consumers
\Describe the water cycle - ANS-1. Evaporation: water evaporates from the surface of land
and bodies of water
2. Transpiration: loss of water vapour from plants directly into the atmosphere
3. Respiration: loss of water vapour from animals directly into the atmosphere
4. Condensation: it rises into the air and condenses to form clouds
5. Precipitation: water droplets in clouds get heavier and fall as rain, snow or hail
\Detritivores - ANS-Detritivores/detritus feeders e.g. maggots and flies feed on dead, rotting
material. They break up the dead organism into smaller pieces, increasing the surface area
for digestion by microorganisms.
\Eaxmple of extremophiles - ANS-bacteria living in deep sea vents (at very high pressure, no
light, acid pH)
\Embryonic screening 3 pros/3 cons - ANS-Pros
1-helps to stop suffering
2-There are laws to stop it going too far-parents can't select sex of baby.
3-Treatment for genetic disorders costs NHS/tax payers money
Cons
1-implies people with genetic disorders are undesirable, leads to prejudice.
2-Screening is Expensive.
3-Could lead to designer babies e.g. parents want a blonde eyed, blonde haired boy.
\Environmental changes affect... - ANS-...the distribution of species in an ecosystem
\Ethical objections to modern intensive farming methods - ANS-1. Intensively farmed animals
suffer in uncomfortable conditions
2. They are not kept in their natural habitat
3. Furthermore intensive farming is not necessarily successful as studies show contented
animals gain biomass faster
\Evaluate the benefits and risks of procedures carried out on the brain and the nervous
system. - ANS-+ve- Can lead to the treatment for disorders of the nervous system
-ve- The brain is complex and delicate. The treatment of brain damage is difficult. It also
carries risks such as physical damage or increased problems with brain damage e.g.
speech.
NB: ADD A CONCLUSION.
\Example of a pathogen affecting food security - ANS-'Blue tongue' disease carried by
midges spreading to sheep and cattle in the UK from Europe
\Examples of behavioural adaptations - ANS-Basking, migration, tool use - e.g. birds
migrate, nocturnal to avoid heat of day
