AQA GCSE Biology Unit 3 (including CGP revision guide page numbers)
- Created by: anna
- Created on: 12-05-13 14:30
View mindmap
- Biology Unit 3 (for CGP revision guide)
- 3b (humans and their environment)
- human impact on the environment (p89)
- humans reduce the amount of land available to other plants and animals by...
- farming
- dumping waste
- building
- quarrying
- we are producing more waste. this affects...
- land
- nuclear waste is buried underground and a lot of household waste is dumped in landfills
- water
- sewage and toxic chemicals can pollute lakes, rivers and oceans
- air
- smoke and gases are released into the atmosphere, polluting it
- land
- the population is rising due to...
- modern farming methods
- modern medicine
- humans reduce the amount of land available to other plants and animals by...
- biofuels (p93)
- ethanol
- anaerobic fermentation of sugar
- glucose broken down by yeast
- anaerobic fermentation of sugar
- biogas
- anaerobic fermentation of waste material
- plant and animal waste broken down by lots of different microorgansims
- anaerobic fermentation of waste material
- ethanol
- carbon dioxide and the greenhouse effect (p90)
- carbon dioxide can be locked up in natural stores...
- green plants
- oceans, lakes and ponds
- peat bogs
- Untitled
- the greenhouse effect
- gases in the atmosphere naturally act like an insulating layer- e.g....
- methane
- carbon dioxide
- the earth is gradually heating up because of the increasing levels of greenhouse gases
- gases in the atmosphere naturally act like an insulating layer- e.g....
- carbon dioxide can be locked up in natural stores...
- using biogas generators (p94)
- batch generators
- make biogas in small batches
- manually loaded up with waste
- by-products are cleared away after each session
- continuous generators
- make biogas all the time
- waste is continually fed in
- biogas is produced at a steady rate
- more suited to large scale projects
- factors to consider when designing a generator
- cost
- convenience
- efficiency
- position
- greener alternative to fossil fuels
- batch generators
- deforestation and the destruction of peat bogs (p91)
- deforestation leads to...
- less carbon dioxide taken in
- more carbon dioxide in the atmosphere
- less biodiversity
- more methane in the atmosphere
- deforestation is done to...
- provide timber
- clear land for framing
- produce paper
- peat bogs
- areas of land that are acidic and water logged
- plants that live there dont completley decay when they die because there is not enough oxygen
- the partly rotted plants gradually build up to form peat
- the carbon in the plants is stored in the peat instead of being released into the atmosphere
- peat starts to decompose when bogs are drained, so carbon dioxide is released
- deforestation leads to...
- managing food production (p95)
- the efficiency of food production can be improved by...
- restricting the energy lost by farm animals
- reducing the number of stages in the food chain
- developing new food sources like mycoprotein
- the efficiency of food production can be improved by...
- climate change (p 92)
- consequences of global warming
- as the sea get warmer, it expands, causing sea levels to rise
- the distribution of many wild animal and plant species may change
- biodiversity could be reduced
- changing weather patterns
- changes in migration patterns
- higher temperatures make ice melt, causing sea levels to rise
- consequences of global warming
- problems with food production and distribution (p96)
- some people think that...
- the conditions of the animals are cruel
- disease
- to try and prevent disease animals are given antibiotics which can enter humans when the animals are eaten
- then antibiotics will become less effective in humans
- the conditions make it easy for disease to spread
- to try and prevent disease animals are given antibiotics which can enter humans when the animals are eaten
- some people think that...
- human impact on the environment (p89)
- 3a (life processes)
- Osmosis (p 73)
- the movement of water molecules across a partially permeable membrane from a region of low water concentration to a region of high water concentration
- a type of diffusion
- water moves into and out of cells by osmosis
- tissue fluid will usually have a different concentration to the fluid inside a cell
- diffusion through cell membranes (p 76)
- gas exchange happens in the lungs
- lungs contain alveoli where gas exchange takes place- they have...
- very thin walls
- a moist lining for dissolving gases
- a good blood suppy
- an enormous surface area
- lungs contain alveoli where gas exchange takes place- they have...
- digested food is diffused from the gut to the blood
- the inside of the small intestine is covered in tiny projections called villi. they have...
- a single layer of surface cells
- a good blood suppy
- the inside of the small intestine is covered in tiny projections called villi. they have...
- gas exchange happens in the lungs
- gas and solute exchange (p 74)
- substances move by diffusion, osmosis and active transport
- exchange surfaces are adapted to maximise effectiveness
- thin - so substances only have a short distance to diffuse
- large surface area- so lots of the substance can diffuse across at once
- in animals they have lots of blood vessels- to get things in and out of the blood quickly
- in animals they are often ventilated too
- active transport (p77)
- absorption of substances against the concentration gradient using energy
- used in the gut when there is a low concentration of nutrients in the gut but a high concentration of nutrients in the blood
- root hairs take in minerals using active transport
- the concentration of minerals is usually higher in the root hair cell than in the soil around it
- the breathing system (p 75)
- ventilation
- breathing out
- intercostal muscles and diaphragm relax
- thorax volume decreases
- this increases the pressure, so air is forced out
- breathing in
- intercostal muscles and diaphragm contract
- thorax volume increases
- this decreases the pressure, drawing air in
- breathing out
- ventilation
- water flow through plants (p78)
- phloem tubes
- transport food
- made of columns of living cells with small holes in the end to allow substances to flow through
- the transport goes in both directions
- xylem tubes
- take water up
- made of dead cells joined end to end with no walls between them and a hole down the middle
- carry water and minerals from the roots to the stem and leaves
- phloem tubes
- circulatory system- the heart (p79)
- the flow of blood through the heart
- circulatory system- blood vessels (p80)
- arteries
- carry blood away from the heart
- walls are strong and elastic because of the high pressure
- veins
- carry blood to the heart
- thinner walls than arteries because of lower pressure
- have valves to keep blood flowing in the right direction
- capillaries
- very small
- exchange substances with cells
- walls only one cell thick
- permeable walls
- arteries
- circulatory system- the blood (p81)
- red blood cells
- carry oxygen from the lungs to the cells
- concave- giving it a large surface area
- contain haemoglobin- combines with oxygen to form oxyhaemoglobin.
- reverses in body tissues- oxyhaemoglobin splits into haemoglobinand oxygen to release oxygen to the cells
- white blood cells
- change shape to digest foreign microorganisms
- have a nucleus
- produce antibodies and antitoxins
- platlets
- small fragments of cells, that have no nucleus
- help the blood to clot
- plasma
- carries everything in the blood
- red and white blood cells and platlets
- nutrients like glucose and amino acids
- hormones
- carbon dioxide and urea
- antibodies and antitoxins
- carries everything in the blood
- red blood cells
- circulation aids (p82)
- artificial blood
- a blood substitute (e.g. saline) is used to replace the lost volume of blood
- gives the patient enough time to produce new blood cells
- artificial parts (for the heart)
- artificial hearts
- mechanical devices put into a person to pump blood if their own heart fails
- temporary - until a donor heart is found
- parts of it could wear out or motor could fail
- valves
- mechanical
- less drastic prcedure than a whole heart transplant
- artificial hearts
- stents
- tubes inserted inside arteries to keep them open
- lower the risk of a heart attack in people with coronary heart disease
- artificial blood
- homeostasis (p83)
- temperature
- too cold
- no sweat produced
- hairs stand up
- blood vessels constrict
- shiver
- too hot
- sweat produced
- hairs lie flat
- blood vessels dilate
- too cold
- water content
- ion content
- blood sugar level
- carbon dioxide
- urea
- the maintenance of a constant internal environment
- temperature
- the kidneys and homeostasis (p84)
- the kidneys...
- adjust ion content
- remove urea
- adjust water content
- the kidneys...
- kidney function (p85)
- nephrons
- (filtration units in the kidneys)
- water, urea, ions and sugar is squeezed out of the blood and into the bowmans capsule
- big molecules like protein and blood cells stay in the blood
- useful substances are reabsorbed back into the blood
- the remaining substances such as urea continue out of the nephron and into the bladder
- useful substances are reabsorbed back into the blood
- the remaining substances such as urea continue out of the nephron and into the bladder
- nephrons
- kidney failure (p86)
- dialysis
- has to be done regularly
- the persons blood flows along a selectively permeable barrier surrounded by dialysis fluid
- only waste and excess substances diffuse across the barrier
- transplants
- a donor kidney could be rejected by the patient's immune system, so...
- donor's tissue type has to closely match the patient's
- the patient is treated with immuno-suppressants
- a donor kidney could be rejected by the patient's immune system, so...
- dialysis
- controlling blood glucose (p87)
- blood glucose levels
- too high- insulin added
- too low- glucagon added
- type 1 diabetes
- caused by a lack of insulin
- can be controlled by...
- avoiding carbohydrate rich foods
- injecting insulin
- blood glucose levels
- Osmosis (p 73)
- 3b (humans and their environment)
- the movement of water molecules across a partially permeable membrane from a region of low water concentration to a region of high water concentration
Similar Biology resources:
Teacher recommended
Comments
No comments have yet been made