8508436
Description
Flashcards by Natalia Cliff, updated more than 1 year ago
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Created by Natalia Cliff
about 7 years ago
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| Question | Answer |
| How do dissolved substances move? | By diffusion or active transport |
| What is Osmosis? | The diffusion of water from a dilute to a more concentrated solution through a partially permeable membrane that allows the passage of water molecules |
| What do soft drinks contain? | -Water -Sugar -Ions |
| What do sports drinks contain? Why? | -sugars to replace the sugar used in energy release during the activity -Water to replace the water lost in sweating -Ions to replace the ions lost in sweating |
| What happens if water and ions are not replaced? | The ion/water balance inside the body is disturbed so cells don't function as effectively (diffusion and osmosis affected as concentration gradients are different) |
| What is active transport? | -When substances are absorbed against the concentration gradient -Requires energy from respiration |
| Why is active transport useful? | Sometimes cells need to absorb ions against the concentration gradient |
| How are organ systems specialised to exchange materials? | The exchange surfaces have: -a large surface area -are thin (short diffusion path) -an efficient blood supply -are well ventilated (for gaseous exchange) |
| What exchange surfaces are are adapted to maximise effectiveness | Gas and solute exchange surfaces (in humans and animals) |
| How are human lungs adapted? | The surface area is increased through alveoli |
| How are small intestines adapted? | -Large surface area due to villi -Large network of capillaries (short diffusion path) takes the digested food away (high concentration gradient) -Absorbs products of digestion through active transport and diffusion |
| Label this Diagram | |
| Describe this diagram | The lungs are in the upper part of the body (thorax), protected by the ribcage and separated from the abdomen by the diaphragm |
| What does the breathing system do? | Takes air into and out of the body so that oxygen from the air can diffuse from air into bloodstream and carbon dioxide diffuses from bloodstream into the air |
| What happens when we inhale? | -Ribcage moves up and out -Diaphragm becomes flatter -Causes pressure to decrease, making air flow into our lungs |
| What happens when we exhale? | -Ribcage moves back -Diaphragm moves back -Pressure increases, making air move out of lungs |
| What is ventialtion? | The movement of air into and out of the lungs |
| What exchanges occur in plants? | -Carbon dioxide enters leaves by diffusion -Water and mineral ions are absorbed by the roots |
| How are these exchange surfaces adapted? | -Roots have a large surface area due to root hairs -Leaves have a large surface area due to flat shape and internal air spaces |
| What do Stomata do? | -obtain carbon dioxide from the atmosphere -Remove oxygen that is produced by photosynthesis -Found at the bottom of leaves |
| Where does the majority of water loss in a plant occur? | Water vapour escapes through the stomata |
| What affects plant water loss? | -Evaporation occurs faster in dry, windy and hot conditions -If plants lose water faster than the roots can replace it stomata can close to prevent wilting |
| What controls the stomata? | The stomata is controlled by guard cells that surround it |
| What does the circulatory system do? | Transports substances around the body |
| What is the heart? What is it made of? | The heart is an organ that pumps blood around te body. Majority of the wall of the heart is made of muscle |
| List the parts of the heart | |
| Describe how blood flows through the heart | Vena cave -> Right atrium -> right ventricle -> pulmonary artery -> lungs -> pulmonary vein -> left atrium -> left ventricle -> aorta -> body |
| What are artery walls made of? | Arteries have very thick walls made of muscle and elastic fibre |
| What are Veins made of? | Veins have thinner walls and often have valves to prevent the backflow of blood |
| What does blood do in the organs? | -Flows through thin-walled capillaries -Substances needed by cells in the body tissue passes out of the blood -Substances produced by the cells pass into the blood (through capillary walls) |
| What is blood made of? | Blood is a tissue made of: -Mainly plasma -Suspended red blood cells -Suspended white blood cells -Suspended platletes |
| What does blood plasma transport? | -CO2 (from organs to lungs) -Soluble products of digestion (from small intestine to organs) -Urea (from liver to kidney) |
| What do red blood cells do? | Transport oxygen from the lungs to organs |
| How are red blood cells adapted for this job? | They have no nucleus so that they can be packed with more of the red pigment hemoglobin |
| How does haemoglobin work? | -Haemoglobin combines with oxygen in the lungs to form oxyhaemoglobin -In the organs oxyhaemoglobin splits into haemoglobin and oxygen again |
| What are white blood cells? | -Part of the body's defence system against microorganisms -They have nucleus's |
| What are platelets? | -Small fragments of cells -Have no nucleus -Help to clot the blood at the site of a wound |
| What are the transport systems in plants? | -Xylem tissue transports water and mineral ions from the roots to the stem and leaves -Phloem tissue carries dissolved sugars from the leaves to the rest of the plant, including growing and storage systems -Movement of water from the roots through the xylem and out of the leaves is called the transpiration stream |
| What are the types of breathing aids? | -Negative pressure where the patient is put in an airtight machine from neck down. Pressure in the machine is alternated to cause ventilation -Positive pressure is forcing air through a pipe into the trachea |
| Advantages and disadvantages of negative pressure | -Has effectively treated polio patients -Patient is confined to a machine -Can cause pooling of blood around the abdomen |
| Advantages and disadvantages of positive pressure | -Useful during operations when the surgeon has to access the whole body -Effective at ventilating the lungs -Long term ventilation requires the tube to be surgically inserted to the trachea through the neck |
| What waste needs to be removed from the body? | -Carbon dioxide produced by respiration and removed via the lungs when we breathe out -Urea, produced in the liver by the breakdown of amino acids and removed by the kidneys in the urine, temporarily stored in the bladder |
| Water and Ion content balance | -Water and ions enter the body when we eat or drink -Leave the body through sweating and urine -If the water or ion content of the body is wrong, too much water may move into or out of the cells and damage them |
| How does a kidney produce urine? | -First filters the blood -Reabsorbs all of the sugar -Reabsorbs all of the dissolved ions needed by the body -Reabsorbs as much water as the body needs -Releases urea and excess water and ions |
| How can you treat kidney failure? | -Kidney dialysis -Kidney transplant |
| Dialysis treatment | -Restores the concentration of dissolved substances in the blood to normal levels -Has to be carried out at regular intervals -In a dialysis machine the persons blood flows through partially permeable membranes -Dialysis liquid has the same concentration of useful substances as the blood to ensure glucose and mineral ions aren't lost -Urea passes from the blood into the dialysis fluid |
| Kidney transplants | -Diseased kidney is replaced with a healthy one from a donor -The donor kidney could be rejected by the immune system without precautions -Antigens are proteins on the surface of cells -Recipients antibodies may attack the antigens on the door's kidney as they don't recognise the organ as they're own -To prevent rejection the recipient is treated with drugs that suppress the immune system -And a donor kidney with a tissue-type similar to the recipient is chosen |
| Advantages and disadvantages of dialysis | -Availabe for all kidney patients -No need for immune suppressing drugs -Must limit salt and protein intake -Expensive for NHS -Regular dialysis treatment affects patients lifestyle |
| Advantages and disadvantages of kidney transplants | -Overall cheaper for the NHS -Can lead a normal life without a special diet -Immune suppressant drugs increase chances of infection -Operation has risks -Kidney only lasts 8-9 years -Shortage of kidneys |
| Sweating | -Cools down the body by evaporation -More water is lost, so more water must be taken as drink or food to balance this |
| How is body temperature monitored and controlled? | -Thermoregulatory center in the brain -Has receptors sensitive to temperature of blood flowing through the brain -Temperature receptors in the skin send impulses to the thermoregularity centre |
| If core body temperature is too high... | -Blood vessels supplying capillaries dilate so more blood flows through the capillaries so more heat is lost -Sweat glands release more sweat which cools the body as it evaporates |
| If core body temperature is too low... | -Blood vessels supplying the skin capillaries constrict to reduce the flow of blood through the capillaries thereby reducing heat loss -Muscles 'shiver', the contraction needs respiration which releases some energy to warm the body |
| Pancreas' role in sugar level control | -Pancreas monitors and controls the blood glucose concentration -Produces the hormone insulin which allows glucose to move from the blood into the cells -Produces glucagon when blood glucose levels fall -Glucagon causes glycogen to be converted into glucose and released into the blood |
| Type 1 diabetes | -Disorder where a persons blood glucose concentration may rise to a high level because the pancreas does not produce enough insulin -Controlled by careful attention to diet, exercise and injecting insulin |
| Why is the amount of waste we produce increasing? | -Rapid growth of the human population -Increase in standard of living -If this waste isn't handled properly pollution occurs |
| Waste can pollute... | -Water with sewage, fertiliser and toxic chemicals -Air with smoke and gases such as sulphur dioxide -Land, with toxic chemicals like pesticides and herbicides, these can be washed from the land into waterways |
| Human use of land | Reduces land available for other species by: -Building -Quarrying -Farming -Dumping waste |
| Why does deforestation occur? | -For timber -Crops can be grown for biofuel (e.g. crops that can make ethanol) -Increase in cattle and rice fields for food -These organisms produce methane, increasing the amount of methane in the atmosphee |
| How does deforestation affect the environment? | -Increased levels of CO2 release as wood is burned or microorganisms decay it -Reduced rate at which carbon dioxide is removed from the atmosphere and locked up for many years as wood Leads to a decrease in biodiversity |
| Peat bogs | -Form in areas where plants grow in waterlogged conditions -When they die they don't fully decompose -Carbon is 'locked up' in peat bogs -Peat can be used as compost in agriculture to increase the nutrient content of soil -So peat bogs are being destroyed -This releases CO2 so peat free compost is important |
| Global warming | -CO2 and Methane levels in the atmosphere are rising -This contributes to global warming -An increase of only a few degrees Celsius can have a significant impact |
| Effects of global warming | -May cause big changes in climate -May cause a rise in sea levels -May reduce biodiversity -May Cause changes to migration patterns -May result in a change in the distribution of species |
| Sequestering of carbon dioxide | -CO2 sequesters in oceans, lakes and ponds -Important factor in removing CO2 from the atmosphere -However, the solubility of CO2 in water decreases at higher temperatures |
| Measuring concentrations of Co2 | -Carbon dioxide concentrations naturally change -To measure atmospheric CO2 concentrations before this, scientists can measure bubbles of air trapped in polar ice caps -Some data indicates that there has been a large increase of CO2 since the industrial revolution |
| Production of biofuels | -Can be made from natural processes like fermentation -Biogas, mainly methane, can be made from anaerobic fermentation of a wide range of plant products or waste material containing carbohydrates -On a large scale Waste from sugar factories and sewage works can be used -On a small scale plant waste from crops and animal faeces and urine can be used |
| Advantaged of biofuels | -Useful way of recycling waste material -initial set up cost expensive but raw materials are cheap -Fuel is readily available -Useful in developing countries -Waste products can be used as fertiliser -Reduces use of fossil fuels |
| Advantages and disadvantages of small biogas generators | -Fewer metal parts so less expensive and doesn't rust -Cheaper to set up, useful for small communities -Gas pressure fluctuates -Less straightforward to control -Gas leakage is more likely methane production is low |
| Advantages and disadvantages of larger biogas generators | -Stabilises gas pressure -Gas production can be monitored more easily -Can be used on a larger scale -Expensive to set up and maintain -Rusts easily -Requires more management |
| Loss of biomass in the food chain | -At each stage of the food chain, less material and energy are contained in the biomass of the organisms -Efficiency of food production can be improved by reducing the number of stages in food chains -This may require more people to convert to a vegetarian diet |
| Increasing efficiency of food production | Restricting the energy lost from animals by: -Limiting their movement -Regulating their temperature This has ethical concerns though: -Animals movement is limited -Suffer pain and discomfort -Don't live in their natural environment -Antibiotics used to treat against disease |
| Food Miles | -The distance food has been transported from producer to consumer -Food transport adds millions of tonnes of CO2 to the atmosphere every year =Reducing food miles can significantly reduce CO2 emissions |
| Sustainable development | ABout how we should ensure that we: -Conserve natural resources -Reduce the damage to the environment -Maintain biodiversity This will be a compromise between competeing priorities |
| Dealing with overfishing | -Fish stocks in the oceans are declining -Need to maintain fish stocks at a level where breeding continues or certain species can die out -Net sizes mean only mature fish can be caught -Fishing quotas limit the amount of fish caught, but drive fish prices up and reduce a fishermans income |
| Fusarium | -Fungus Fusarium is useful for producing mycoprotein, a protein-rich substance for vegetarians -Grown on glucose syrup -Aerobic conditions -Biomass is harvested and purified -May become more important when land availability for farms becomes restrictive |
| Providing food | -Various organisations provide emergency food assistance after natural disasters -Countries who struggle with food production are advised to grow staple crops like cereals, their seeds are high in protein and can be stored year round -GM crops have been developed, but use is banned in many countries |
| Providing water | -Many people in less developed countries have no access to clean water -Contaminated water can carry harmful bacteria -Some charitable agencies provide pumps, pipes and education -Demand for water is often greater than supply from rivers, lakes and underground aquifers -People need to reduce water use, especially for irrigation -Hose pipe bans enforced to reduce residential water use |
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