Karteikarten
Biology IGCSE
Karten in diesem Stapel (77)
- 1LipidsOil
Butter
Eggs
Dairy food - 2ProteinsMeat
Fish
Cheese
Body building, growth and repair - 3CarbohydratesSource of energy
Bread
Pasta
Rice - 4Vitamin AGood eyesight and healthy hair
Fish liver oils
Liver
Butter
Margarine
Carrots - 5Vitamin cGrowth and repair of tissues
Citrus fruits and vegetables - 6Vitamin DHelps bones absorb calcium and phosphorus
Fish liver oils, butter, made by skin in sunlight - 7CalciumMake bones and teeth
Dairy products
Fish
Bread
Vegetables - 8IronMake haemoglobin in red blood cells
Red meat
Liver
Eggs
Green leafy vegetables - 9RicketsLack of vitamin D
- 10ScurvyLack of vitamin C
- 11WaterSolvent for the body
Enzymes work in solution
Carrying substances around the body - 12FibreAbsorbs lots of water
So food can move through the gut more easily - 13How food moves through the gutWaves of muscle contractions known as peristalsis
- 14BileMade in the liver
Stored in the gall bladder
Emulsifies fats
Neutralises stomach acids - 15Egestion and excretionRemoval of undigested food out of the anus as faeces.
Removing waste products of metabolism like urea and carbon dioxide. - 16Absorption and assimilationAbsorption is when digested food molecules are absorbed into the bloodstream in the small intestine
Assimilation is when the digested food products are absorbed into the cells of the body by diffusion and assimilated (used for energy and to build up into chemicals needed by the cells) - 17BloodPlasma
White blood cells
Red blood cells
Platelets - 18nitratesamino acids and proteins
cell growth
stunted and yellow older leaves - 19phosphatesMaking DNA, cell membranes respiration and growth
Poor root growth and yellow older leaves - 20potassiumhelp enzymes for photosynthesis and respiration
poor root and flower growth
discoloured leaves - 21Magnesiummaking chlorophyll for photosynthesis
yellow leaves. - 22need for transport systemsin order to deliver and take away substances to and from individual cells quickly
- 23transport system in plantsxylem and phloem- vascular bundle
- 24xylemcarry water and mineral ions from roots up the shoot to the leaves in the transpiration stream.
- 25phloemtransport sugars, like sucrose and amino acids from where they are made to other parts of a plant.
- 26translocationmovement of food substances around the plant
- 27Root hair cellsdraw in water by osmosis - higher concentration usually in soil, and they take in minerals by active transport
- 28waxy cuticleprevents water loss by evaporation, NOT transpiration!
- 29why do plants have a transpiration streambecause plants constantly need to draw up water from the roots through the xylem vessels in order to replace the water lost by evaporation
- 30why is there transpirationbecause there needs to be stomata for gas exchange for photosynthesis, but because there is more water inside the leaf than outside of the leaf, water escaped the leaves through the stomata by diffusion
- 31factors which affect the rate of transpirationWind speed
Humidity
Temperature
Light intensity - 32HumidityHigh humidity- air is moist- not steep concentration gradient- low transpiration rate
Low humidity- transpiration rate is fast, as it is drier, so water moves from high to low concentration - 33Estimating transpiration rateUse a potometer
- 34investigating how humidity affects transpirationseal potometer with a plastic bag that has been sprayed with al little bit of water
wind speed- use a fan to increase wind speed around the potometer
temp- put potometer in a colder or warmer room
Light intensity- put potometer in a dark cupboard or use a lamp. - 35photosynthesis and respirationlight energy - chemical energy sotred in bonds of glucose- released in respiration-
chemical energy used to create large molecules like proteins , and heat energy is used to maintain a steady body temperature - 36Respirationuses oxygen made a a waste product of photosythesis.
co2 always enter the leaves becasue there is always a higher conc of it outside than inside the leaf as the leaves constantyl use it in photosythesis - 37Factors affecting rate of diffusionSurface area to volume ratio
Temperature
Concentration gradient- does not affect active transport - 38How leaves are adapted for gas exchange- different to how leaves are adapted to photosynthesisthin- short diffusion distance
large surface area- for diffusion
stomata- close when soil is dry, or when it is dark, so water is not lost.
air spaces- gases can diffuse easily
lots of stomata- gases to diffuse easily - 39stomataclose when dark- no photosythesis so no co2 required- reduces water loss by transiratino
close when soil is dry- less water available for them to drw up from soil, so need to close to save water- die becasue they cannot photosynthesize. - 40guard cellscontrol the opening and closing of the stomata
- 41how alveoli are specialised for gas exchangeincrease the surface area of lungs greatly.
moist lining - gases to dissolve in
alveoli have very thin walls- short diffusion distance
rich blood supply- maintain steep concentration gradients
walls are permeable- gases can diffuse across easily - 42Smoking tobaccoNicotine- addivtive drug
carbon monoxide- binds to haemoglobin- stillbirths and smaller babies
tar- cause cells to mutate to form cancer in in lungs and in throat
tar-damage cilia- dirt and pathogens are not swept away so infections are results
emphysema- when walls of alveoli become large and irregular making diffusion of gases less efficient as surface area is reduced
tobacco smoke contains carcinogens- chemicals that can cause cancer
tar irritated bronchioles- smokers cough - 43how smoking can cause coronary heart diseasedue to co3 binding to haemoglobin, heart rate increases to deliver more oxygen to cells more quickly , which leads to increase in blood pressure.
high blood pressure damages artery walls, making formation of blood clots more likely- risk of cornary heart disease increases - 44ExperimentsReliability-repeats at least three times
Validity-repeats and fair test
Fair test- only have one independent variable - 45The need for a control variableIn some experiments it is too hard to control all of the variables other than the independent variable, so having a control allows you to see what happens when you change nothing at all
- 46reliabilityrepeat experiment three times and take a mean or an average
- 47anomaliesignore anomalies when calculating an average
- 48graph know howindependent variable goes on x axis
if data is continuous- e.g temp- use a line graph
if data is discrete- categoric- use a bar chart, and have spaces in between - 49Evaluating a conclusionsay whether the evidence from the experiment supports the conclusion
- 50reducing risks of fireput bunsen burner on hear proof mat
- 51how to improve accuracy and precisionusually need to change your method- e.g use a gas syringe instead of counting number of bubbles produced as these could be different sizes and you may miss some bubbles when counting if produced quickly
- 52precisionuse more sensitive apparatus intruments like mm ruler not cm ruler
measure to 3 sf not to nearest whole number - 53pesticidesgive a very high yield
easy to apply
increase profits
a lot are not specific
often poisonous to humans
affect food chains
pests can develop resistance
can be leached into rivers, but do not cause eutrophication - 54biological controlno harm to environment
highly specific- not affect food chains
long lasting
natural predators can become pests themselves - 55Fertilisersneeded to replace elements that are missing from the soil, because previous crops used them up
provide more of these elements that are important eg nitrates, - 56Methods of increasing crop yieldsartifically creating ideal conditions for photosynthesis
fertilisers
biological or chemical pest control - 57biological controlusing other organisms to reduce the numbers of pests
predators
disease causing
parasites - 58PlasmaDigested food molecules- glucose and amino acids
hormones
heat energy
urea from liver kidneys- where it is removed
carbon dioxide - 59Plateletssmall fragments of cells that help blood clot
stops you losing too min blood, and prevents micro-organisms from entering the wound
mesh of fibrin (protein) forms, which holds platelets together.
this process needs other clotting factors too though - 60Red blood cellsbiconcave- large surface area for absorbing and releasing oxygen.
no nucleus- more space for more haemoglobin- so more oxygen can be carried
contain haemoglobin- contains lots of iron- gives red colour - 61HaemoglobinBinds with oxygen to form oxyhaemoglobin in lungs.
In body tissues, oxyhemoglobin converts to oxygen and haemoglobin - releasing oxygen into cells - 62Function of immune systemdeals with pathogens- cause disease
immune system needs to respond quickly so that the pathogens do not reproduce rapidly - 63Phagocytesingest pathogens- by engulfing them
non specific- so they attack anything that it not meant to be there - 64lymphocytesproduce antibodies that are specific to the surface antigens -label them
antibodies are then produced rapidly and flow around the body to mark all similar pathogens - 65memory cellsform when some of the lymphocytes stay around in the the blood after the original infection was fought off.
makes us immune to most diseases because the body has a memory of what the antigen was like, so can produce loads of antibodies to label the antigens before it infect you- quick - 66P2- VaccinationNeeded because it can take a while for body to produce lymphocytes to label the antigens
inject dead or inactive pathogens- carry harmless antigens but they still trigger immune response
lymphocytes produce antibodies to attack them
some of these lymphocytes remain in blood as memory cells, so if body is infected with the same pathogen, they can produce antibodies quickly to fight off pathogen before it can multiply and make you il. - 67Capillariesinvolved in the exchange of materials at the tissues
- 68valves in veinskeep blood flowing in the right direction- prevents back flow of blood
- 69Arteries and veinsPulmonary artery is the only artery that carries deoxygenated blood away from the heart
Pulmonary vein is the only vein that carries oxygenated blood towards the heart - 70Exercise increases heart ratemuscles need more energy so respire more- blood needs to be pumped round body faster to deliver oxygen so heart rate must increase
receptors in aorta detect high levels of co2 in blood.
send signals to brain
brain sends signals to heart, causing it to contract more frequently and with more force - 71Hormonal system helps to control heart ratebody is threatened
Adrenal glands release adrenaline- binds to specific receptors in heart- causes muscles to contract more frequently and with more force- so heart rate increases and heart pumps more blood.
increases oxygen supply to tissues- getting body ready for action - 72Types of systemsdigestive
circulatory
respiratory
reproductive
excretory - 73circulation sytemmade up of heart and blood vessels
- 74ways of remembering structure of circulatory systemhepatic- liver
renal- kidney
pulmonary- heart - 75Exctretion- refer to notesrevise this section but none is paper 2
- 76CNScoordinates a response
response requires a stimulus, receptor and effector - 77neuronestransmit information using high speed electrical impulses
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