Combined science Biology (PAPER 2) Flashcards (Edexcel 9-1).

Eleanor Rose
Flashcards by Eleanor Rose, updated more than 1 year ago
Eleanor Rose
Created by Eleanor Rose over 2 years ago


All information from Edexcel 9-1 revision guide for paper 2.

Resource summary

Question Answer
What is the word equation for photosynthesis? carbon dioxide + water = glucose + oxygen.
Define biomass. Mass of living material at a particular stage in a food chain.
Name two limiting factors for photosynthesis and say how they affect the rate of photosynthesis. Carbon dioxide concentration = Increase in concentration increases rate of photosynthesis and is used to make more sugars. Temperature = Increase in temperature increases the kinetic energy of molecules and rate of enzyme activity.
Describe the conclusion of the investigation of how light intensity affects the rate of photosynthesis. As distance increases, light intensity falls and so the rate of photosynthesis decreases. This is because energy transferred by light is needed for photosynthesis to take place.
What is the specialised function of Phloem? They contain sieve tube elements which have very little cytoplasm so there is lots of space to transport sucrose and other nutrients.
What is the specialised function for Xylem? They are dead cells so they have no cytoplasm or cell contents so there is more space for water containing mineral ions to move through.
Define transpiration and transpiration stream. Transpiration = loss of water by evaporation from the leaves. Transpiration stream = movement of water from the roots to the leaves.
Where is the stomata mainly found? On the lower surface of the leaf.
How does the stoma open? The guard cells take in water by osmosis and they swell which causes the stoma to open.
How does the stoma close? When the guard cells lose water, they become flaccid and this causes the stoma to close.
Define translocation. Transport of sucrose and other nutrients around a plant by the phloem.
Describe the process of translocation in three steps. 1) Sucrose is produced in leaves from glucose formed during photosynthesis. 2) Dissolved sucrose is carried around the plant in the phloem 3) Dissolved sugars convert to starch and are stored in storage organs to be used later.
Name three environmental factors that change the rate of water uptake in plants. Light intensity = Causes stomata to open, increases evaporation so more water is taken up to replace this. Air movement = Wind blows moist air away so keeps the diffusion gradient high. Temperature = The higher the temp, the more energy water molecules have..
Rate of transpiration can be measured by: distance moved ------------------- time taken
Name the three hormones in the pituitary gland and the effects. Growth hormone = increases rate of growth of many tissues. LH = triggers ovulation. FSH = stimulates growth and maturation.
Name the two hormones in the pancreas and the effects. Glucagon = cells break down. Insulin = increases uptake of glucose from blood.
Name the hormone In the adrenal gland and its effect. Adrenalin = prepares body for action.
Name the hormone in the ovaries and its effect. Oestrogen = secondary sexual characteristic development in girls.
Name the hormone in the testes and its effect. Testosterone = secondary sexual characteristic development in boys.
Name the cause and control of type 1 diabetes. Cause = the person does not produce insulin. Control = inject with insulin.
Name the cause and control of type 2 diabetes. Cause = person does produce insulin but their liver and muscle cells have become resistant to it. Control = Eat foods with less sugar, exercising and using medication if needed.
How do you calculate a person's BMI (Body Mass Index)? weight (kg) --------------------- height (m)2
What are alveoli adapted for? For gas exchange by diffusion between air in the lungs and blood in capillaries.
What happens in the lungs? Oxygen diffuses from the air into the blood. Carbon dioxide diffuses from the blood into the air.
Name the four types of blood. 1) Plasma. 2) Red blood cells. 3) White blood cells. 4) Platelets.
What is plasma's function? Plasma is the liquid part of the blood which carries the blood cells through the blood vessels. And contains many dissolved substances, such as carbon dioxide and glucose.
What is the function of white blood cells? They are part of the immune system and contain a nucleus. Some white blood cells surround pathogens and destroy them. Whilst some white blood cells make antibodies and destroy the pathogens.
What is the function of red blood cells? They contain haemoglobin which carry oxygen and their biconcave shape means it has a large surface area as well as it not having a nucleus. Its easier for oxygen to diffuse in and out of the cell.
What is the function for platelets? They cause blood to clot when a blood vessel has been damaged. The clot blocks the wound and prevents pathogens getting into the blood.
Name the three types of blood vessels. 1) Arteries. 2) Veins. 3) Capillaries.
What is the function of veins? Large space for blood to flow easily back to the heart and valves to stop blood flowing backwards so that it is returned to the heart (long section).
What is the function of arteries? Carry blood away from the heart except pulmonary arteries carry oxygenated blood to the body.
What is the function of capillaries? Exchange substances between the blood and body cells. They diffuse products eg carbon dioxide out of the cell and diffuse substances needed by the cells eg oxygen into the cell.
What takes the blood away from the heart and what brings the blood back to the heart? Away = Arteries. back IN = veINs.
Why is the left ventricle muscle wall thicker than the right ventricle? The left ventricle pushes blood around the body.
What does the pulmonary artery do? Carries deoxygenated blood from the heart to the lungs.
What does the Aorta do? Carries oxygenated blood from heart to body.
What does the vena cava do? Brings deoxygenated blood from body to heart.
What does the pulmonary vein do? brings oxygenated blood from lungs to heart.
Describe the four steps of blood circulation. 1) Blood enters the atria (A before V). 2)The atria contract, forcing blood into the ventricles. 3) The ventricles contract, forcing blood into the arteries. 4) Blood flows through arteries to the organs and returns to the heart through veins.
What's the word equation for aerobic respiration? Glucose + oxygen = carbon dioxide + water.
Name four differences of aerobic and anaerobic respiration? Aerobic = requires oxygen, releases a lot of energy, glucose broken down completely and occurs mostly in mitochondria. Anaerobic = does not require oxygen, releases much less energy, glucose only partly broken down to lactic acid and does not occur in mitochondria.
What is the formula for cardiac output? stroke volume X heart rate.
What happens during exercise? Your heart rate increases. Muscle respire faster which means they need more oxygen and glucose and release carbon dioxide. Your stroke volume increases as the muscles pump more fast. The ventricles become thicker and more powerful.
Define organism. Single living individual.
Define population. All the organisms of the same species in an area.
Define community. All the population in an area.
Define ecosystem. All the living organisms (the community) and the non-living components in an area..
Name three environmental living factors. Prey. Competitor. Predator.
Name five environmental non living factors. Light. Average temperature. Average rainfall. Oxygen levels in water. Pollution.
Define parasitism. Where a parasite feeds on another organism (host) while they are living together. This harms the host but benefits the parasite.
Define mutualism. When two organisms live closely together in a way that benefits both called mutualists.
What is the equation for the number in whole area? Mean number of organisms In one quadrat X total area (m2) ---------------- area of one quadrat (m2).
Name two disadvantages and one advantage of fish farming. D = the waste can pollute the local area, changing the conditions so that some local species can die out. D = diseases from the farmed fish (such as lice) can spread to wild fish and kill them. A = farming fish reduces fishing of wild fish.
Define non indigenous species. Organisms that are not found naturally in the area.
Name two disadvantages and one advantage of non indigenous species. D = they may produce rapidly as they have no natural predators in the new area. D = they may have out complete native species for food or other resources. A = they may provide food for native species.
Define eutrophication. Where fertilisers are added to fields for crops which may run into streams and rivers which add phosphates and nitrates to the water. It can lead to loss of biodiversity in nearby water.
Describe the five steps of eutrophication. 1) Eutrophication causes water plants and algae to grow more quickly. 2) Plants and algae cover the water surface, and block light to deeper water. 3) Deeper plants cannot get light, so they die. 4) Bacteria decompose dying plants and take oxygen from the water. 5) There is not enough oxygen left in the water for fish, so they die.
What are the two key processes in the carbon cycle and state why these are important. Respiration and photosynthesis. They maintain the oxygen and carbon dioxide concentrations in the air.
Explain how distillation can be used to produce potable water in a village that is close to the sea. Salty water is heated until the water evaporates forming steam. The steam is condensed in another container to give pure water. The salt and other impurities are left behind in the salty water. If renewable energy, such as sunlight, is used this saves electricity costs and avoids pollution.
Define crop rotation. Means growing different crops each year on a rotation basis.
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