B7 Flashcards

Question	Answer
What does blood consist of and why is blood vital?	•Carries all the substances needed for us to stay alive - like oxygen, glucose. •Blood is a fluid made up of cells, platelets and plasma.
What are red blood cells and what is their role?	•to transport oxygen from the lungs to rest of body •they are packed with haemoglobin - substance that attaches to oxygen. •they have a concave biconcave shape for a large surface area.
What are plasma and what are their roles?	•liquid carrying nutrients (glucose, amino acids etc) •carries antibodies, hormones, and waste (CO2)
What are white blood cells and what are their roles?	•help fight infection by protecting our body from attacks from microorganisms
What are platelets and what are their roles?	•Small fragments of cells - help the blood to clot at the site of a wound.
Describe each role of the double circulatory system	•Right side - pumps deoxygenated blood from the pulmonary artery to the lungs to be oxygenated. •Left side - the oxygenated blood from the lungs is taken in via the pulmonary vein - then it passes the left atrium, valves, left ventricle, then is pumped to the rest of the body through the aorta.
What is the role of the valves in the heart?	•They prevent back flow of blood, veins also have valves for this reason.
Why is the left ventricle thicker than the right?	•It has to pump blood to the rest of the body, whereas the right only pumps to the lungs, so more force is needed to get it all the way round.
Why do atria have thinner walls?	They only pump blood to the ventricles.
Why do capillaries have permeable walls?	•So that substances can diffuse in and out.
What are networks of capillaries in tissue called?	•They are called capillary beds.
How is tissue fluid formed?	•As blood passes through capillary beds, small molecules are forced out of capillaries to form tissue fluid.
How do substances move between tissue fluid and cells?	•Diffusion.
Name two substances that move from tissue fluid into cells.	•Oxygen and glucose
Name two substances move from CELLS into TISSUE FLUIDS.	•Carbon dioxide, and urea.
Why are tissue fluid essential for a cell's survival?	•Allows cells to get substances they need and get rid of waste without capillaries supplying every cell.
What are the roles of the skeleton?	•Support the body, allows movement, and protect vital organs.
Fish, amphibians, reptiles, birds and mammals are part of what kingdom?	•Vertebrates - they all have a backbone and an inner skeleton.
Give one difference between a vertebrae's skeleton and an insect's skeleton.	•The vertebrae's skeleton is internal - the insect's is external.
What are bones held by? And what is their role?	Ligaments - they stabilise joints and allow movement.
Why do ligaments have high tensile strength?	•so you can pull on them and not snap easily.
What is the role of cartilage on the end of bones?	•They are smooth - reduce friction between bones. It can be compressed - acts as a "shock absorber".
What are the roles of synovial fluid between the joints?	•They lubricate the joints, so movement is easier - less friction.
Bones are attached to muscles via tendons. Explain how muscle move bones at joints in the body.	•Muscles can only pull. To make a joint move, you need muscles that can pull in opposite directions. Antagonistic muscles are pair of muscles that work against each other. As one contracts, the joint moves in one direction as the contracting muscles causes a tendon to pull on the bone, transmitting the force from the muscle to the bone.
What is fitness a measure of?	•How well you can do in physical activities.
Why is exercise important?	•Increases fitness
How can fitness practitioners help with exercise?	•They can design fitness regimes for people - as exercise is most effective when it is structured in a regime.
What do fitness practitioners, like personal trainers and gym instructors, need to know to develop the right exercise regime for an individual?	•Health problems of the individual - need to know symptoms of health problems that can affect a person's ability to participate in exercise e.g blood pressure. •Current medication the individual is taking - some medication affects the ability to exercise - e.g affects co-ordination. •Previous fitness treatments - to see what has worked/not worked before. •Other lifestyle factors - smoking, drinking - affects fitness. •Family medical history - some illnesses can be inherited, some can affect ability to participate in exercise.
What state is our heart rate and blood pressure when we are not exercising?	•Resting level.
What happens to this as we exercise?	•Resting heart rate, and blood pressure increase.
What is the recovery period?	•the time it takes for our heart rate and blood pressure to return to its resting level after exercise. •the fitter you are, the shorter your recovery period.
What is the equation to find a person's BMI?	body mass (in kg) ÷ height squared (meters squared)
Why is BMI not always accurate as an indicator of fitness?	•Someone fit and muscular may be outside the normal range, as muscle is more dense than fat.
What alternative indicator of fitness is there other than BMI?	•Proportion of body fat - someone fit and healthy have lower body fat percentages.
What does repeatability mean?	•Gives reliable results - if the procedure was repeated, you should receive the same/similar results.
What are the implications of excessive exercise?	INJURIES •sprains - damage to ligaments (stretched too much) causes pain too. •Dislocations - bone comes out of socket - causes severe pain •Torn ligaments - ligament tears, causes severe pain as bones are no longer attached firmly together. •Torn tendons - when a muscle contracts in one direction but is being pulled in the other.
What are the main symptoms of a sprain?	•Pain and swelling in the affected area.
What is RICE and how does it help with sprains?	R - rest - avoids further damage, allows the joint to be used more gradually after time passes I - ice - reduces swelling - reduces the temp. and blood flow to the affected area C- compression - firm bandages on the affected area reduces swelling and prevents further damage (make sure it's not too tight otherwise it will cut of the blood flow) •E - elevation - raising an injured limb as high as possible - reduces swelling (easier for blood to flow back to the heart)
How can more serious injuries to the skeletal or muscular system be treated?	•they will be treated by a physiotherapist who will use R.I.C.E, cortisone injections and therapies (such as laser treatment) to speed up healing. •they will also advise us on exercises to do to rehabilitate after injuries.
Describe some of the graded exercises used for a damaged knee, to build up the strength of the knee.	1) Standing up and tensing the muscles without moving the knee 2) Sitting and then slowly raising the damaged leg up and lowering by bending the knee. 3) Stepping up and down, onto and off a low box 4) Standing, and bending and straightening the legs at the knees.
What is the optimum temperature for the body and for the important reactions to take place?	•37ºC
What does the body have to balance to keep the core body temperature constant?	•the amount of heat energy gained and lost
What detects temperature in our bodies?	•Temperature receptors in the skin to detect external temperature. •Hypothalamus in the brain - detects temperature of blood.
Give a brief description of the term accuracy.	•Accuracy means getting results as close as possible to what's actually happening.
Describe another role of the hypothalamus.	•the hypothalamus triggers effectors automatically to control the body's temperature.
Name two effectors that are involved in the regulation of the body temperature.	•Muscles •Glands
What is the name for the mechanism which allows the body to keep its body temperature constant?	•Negative feedback mechanism.
What happens when you are too hot/too cold? Describe each stage.	•Temperature receptors detect that core body temperature is too high/too low. •The hypothalamus acts as a processing centre - receives information from the receptors and triggers the effectors automatically. •Effectors, such as muscles or glands, produce a response to counteract the change.
What is vasodilation and why does it happen?	•blood vessels close to the skin's surface get bigger in diameter - more blood gets to the surface of the skin so more of the heat in the blood is lost to the surrounding's. •this happens when you are too hot.
Give another example of a response produced by our body when we are too hot.	•Sweating through glands - water in sweat evaporates using heat in our body, so more heat is lost, so the body is cooled. However it can cause us to become dehydrated - so less sweat is produced so the body temperature will increase. SO STAY HYDRATED!
What is vasoconstriction and when does it happen?	•Blood vessels close to surface of skin gets smaller in diameter, so less blood reaches the surface - therefore less heat is lost to the surroundings. •This happens when you are too cold.
Give another example of a response that happens when our body is too cold.	•You shiver - muscles contract rapidly. This increases the rate of respiration and warms the tissue surrounding the muscles.
What is the hormone that our body uses to control the level of sugar in the blood?	INSULIN
What are the factors that causes our blood sugar level to rise rapidly?	•Eating foods high in simple sugars - processed food like cereals, biscuits etc.
Why do simple sugars cause our blood sugar level to rise rapidly?	•They are digested and absorbed into our blood extremely quickly.
What response is produced when our the blood in our body has too high of sugar level?	•Insulin is secreted via the pancreas, which causes sugar to be removed from the blood, so blood sugar level falls/decreases.
What is Type 1 diabetes?	•pancreas stops producing insulin •blood sugar level can rise to a dangerous level •controlled by insulin therapy - injecting insulin into the blood, often at mealtimes, it needs to have the right amount so the body doesn't remove to much sugar.
What is Type 2 diabetes?	•late onset diabetes (often developed later in life) •having a poor diet, or being obese increases the risk of developing this type of diabetes. •body no longer responds to its own insulin - therefore less is produced, again can cause the blood sugar level to reach dangerous levels. •can be controlled by exercising and eating a controlled diet.
How can someone with Type 2 Diabetes keep their blood sugar at a steady level?	•By eating foods high in fibre and complex carbohydrates.
How do complex carbohydrates help people with Type 2 Diabetes?	•complex carbohydrates are digested more slowly than simple sugars, so the sugar is absorbed into the blood over a longer period of time - blood sugar rises slower so the body can remove the sugar before it becomes too high (e.g using it for respiration)
For what purposes can micro-organisms be useful for?	•To make things like medicine and food on a large scale.
Some features of micro-organisms can make them ideal for industrial use. List some of these features, and why they are important.	•can reproduce rapidly under the right conditions - products made quicker •contain plasmids - can be genetically modified •their biochemistry is simple - fewer reactions happen within them •can make complex molecules that are difficult to produce artificially •no ethical concerns with the use of them
Large amounts of microorganisms are grown in containers called fermenters which have the optimum conditions required for growth to increase production. State whether an enzyme/bacteria/fungi is used to produce antibiotics and give examples of some.	•Antibiotics - bacteria and fungi used to produce medicines on large scale e.g penicillin is an antibiotic produced from the growth of the fungi "Penicillium" •Enzymes for making food - enzymes are needed to produce certain foods, e.g cheese. Chymosin (vital enzyme in rennet) can be used to produce genetically modified micro-organisms in large quantities. Enzymes for washing powder - enzymes produced by bacteria used to make biological washing powders as they are used to help break down stains. For example amylase enzymes can remove carbohydrate stains (jam, chocolate etc), and lipase to remove fat stains (butter, and oil etc.)
State whether an enzyme/bacteria/fungi is used to produce food and give examples of some.	•Food from fungi - single celled protein from fungi can be used to make meat substitutes for vegetarian meals - "Quorn" •Enzymes for making food - enzymes are needed to produce certain foods, e.g cheese. Chymosin (vital enzyme in rennet) can be used to produce genetically modified micro-organisms in large quantities.
State whether an enzyme/bacteria/fungi is used to produce washing powder and give examples of some.	Enzymes for washing powder - enzymes produced by bacteria used to make biological washing powders as they are used to help break down stains. For example amylase enzymes can remove carbohydrate stains (jam, chocolate etc), and lipase to remove fat stains (butter, and oil etc.)
State whether an enzyme/bacteria/fungi is used to produce biofuels and give examples of some.	•1) Yeast can be used to produce ethanol. In some countries, such as Brazil, cars are adapted to run on a mixture of ethanol and petrol - "gasohol" •2) Micro-organisms can be used to produce biogas - a fuel used for heating, cooking, and lighting. It is made from the fermentation of a plant and animal waste containing carbohydrates.
What is genetic modification?	•It is where a GENE from one ORGANISM is TRANSFERRED to ANOTHER. •the protein can be made even though the gene came from a different organism because all organisms use the SAME genetic code.
What are the important stages involved in genetic modification?	1) The desirable gene used in producing the protein is isolated - located on the DNA. 2) The useful gene is replicated to produce many copies 3) Each gene is joined to a vector (a host) - to make it easier to insert it into a new cell - plasmids and viruses are usually used as vectors. 4) Vectors containing the gene are transferred into new cells - e.g bacterial cells. 5) Not all of the new cells are modified (some are not transferred properly). 6) The individual cells that have been successfully modified are identified and selected.
Genetic modification is useful in making medicines for human use, list some of these uses.	•can produce insulin on a large scale - used to treat diabetes (Type 1) •gene for human insulin production can be transferred into bacteria and into someone who cannot produce insulin •they produce the same exact insulin so there are no adverse allergic reactions
Genetic modification can be used to make crops herbicide resistant. Explain how this happens.	•some plants have natural resistance to herbicides •the gene that is responsible for this can be cut out from the plant's DNA and inserted into a plant which is not herbicide resistant. •this is useful for farmers as they can use a really effective weedkiller without damaging their produce
What are the implications of making crops herbicide resistant?	•plants that are herbicide resistant can be more expensive than normal crops - so there is a worry that the gene might be transferred into wild plants, making them difficult to kill. •they encourage the use of weedkillers - can reduce biodiversity •weed killers can pollute water systems and get into food chains.
Gene testing can help identify genetic disorders. Describe a way you could do this.	•Take DNA sample - DNA isolated from white blood cells - quick, easy to do, and contains lots of WBCs. •Make a gene probe - strand of bases complementary to the faulty gene you are looking for. •Use the gene probe - probe is mixed with DNA, if the gene is present, it will latch onto it.
The gene probe can find a specific sequence of bases. But, you cannot see it with the naked eye. How can you?	•A fluorescent marker is stuck on the end of the sequence bases, so that you can locate the gene probe as you shine UV light on it. The marker shows if the faulty gene is present, and where it is in the DNA sample.
What is nanotechnology?	•It is a new technology using tiny structures that are about the size of molecules.
List some of the uses of nanotechnology.	•Food can last longer, using clay nanoparticles to plastic (makes it better at keeping out oxygen and moisture.) •Some nanoparticles can kill harmful organisms. •"Smart packaging" uses nanoparticles to change the packaging's properties. E.g milk carton could change colour when milk goes off.
Give an example of when stem cell technology can be used to treat a specific illness.	•Leukaemia - (cancer of blood/bone marrow) - bone marrow transplants used to replace faulty bone marrow. The bone marrow contains stem cells that are specialised to form any type of cell. It will produce healthy blood cells.
Give other examples of illnesses that can be treated using stem technology.	•Spinal cord injuries - replacing damaged nerve tissue.
Biomedical engineering uses engineering technologies to improve human health - including the replacement of human body parts. Give an example of this.	•group of cells which determine how fast heart beats stop working - heartbeat can become irregular (dangerous) - cells replaced with an artificial device (pacemaker) under the skin - which produces an electric current to control the heartbeat.
Give another example of this.	•Faulty heart valves can be replaced using animal and mechanical valves.
Describe the characteristics of a closed loop system.	•All outputs from processes and stores are recycled (used for other uses) •No outputs (no waste) and no inputs.
What kind of system is the ecosystem and why?	•It is a closed loop system - waste produced by organisms isn't lost - it is recycled as food or reactants for other organisms.
Give examples of waste products produced by the ecosystem.	•Oxygen - from photosynthesis •Carbon dioxide - from respiration •Dead organic matter (petals, faeces, leaves) used as food for micro-organisms. •Mineral nutrients (nitrogen) - absorbed and used by plants from microorganisms.
Why is no ecosystem a perfect closed loop system?	•some outputs are always lost e.g dead organic matter can be carried out of the system via air or water. e.g some organisms migrate from one ecosystem to another.
Give an example of a stable ecosystem, and why it is stable.	•Rainforest - outputs balanced by gains. E.g water lost through rivers is replaced by the high level of rainfall in the system. E.g vegetation grows in rainforests - which reduces soil erosion e.g leaves protect soil from direct rainfall. And roots help bind the soil together
Give reasons why large amounts of vegetation which grows in rainforests help the ecosystem.	• reduces soil erosion e.g leaves protect soil from direct rainfall. • roots help bind the soil together •prevents extremes pf temperatures. •promotes cloud formation.
What is eutrophication?	•Nitrates from fertilised fields can wash into rivers/lakes. •Causes algae to grow on surface, preventing light to reach plants below the water. •Organisms die (can't photosynthesise) •Bacteria decompose dead material, using oxygen. •Oxygen is not replaced as there is no photosynthesis taking place (apart from the surface) •Animals requiring oxygen die because there is none, so they suffocate.
Give other examples of how human activities can damage ecosystems.	•biomass is take out - over fishing removes food source for organisms in food chain (interdependence is affected) •timber harvesting removes habitats and food sources.
Explain why the removal of vegetation (for agricultural crops and to raise livestock) in an area affects the ecosystem.	•reduces biodiversity •increases soil erosion - leads to soil washing into rivers, so flooding is more likely, and it can cause desertification - land becomes infertile (can't support vegetation)
Human activities can create non-recyclable waste. Give an example of one and how it affects the ecosystem.	•mercury (heavy metal) - released into waters, eaten by small organisms (stored in tissue) - these organisms are eaten by predators, so larger amounts of the metal is stored, which may cause the animal to die.
What is bioaccumulation?	•as you go up the food chain - amount of waste increases (accumulates).
Give reasons why human systems are not closed loop systems.	•we create non-recyclable waste that cannot be used again •we use fossil fuels as energy sources (which comes from OUTSIDE the system) •use of fossil fuels produces waste emissions which can't be used again •fossil fuels take millions of years to form, but we use it so quickly meaning that they cannot be made again in the system.
List reasons why we rely on ecosystems.	•it provides us with clean air, water and food. •provides us with fertile soil full of mineral nutrients - to produce crops •pollination - pollen grains are transferred between plants to be fertilised)
What is sustainability?	•Meeting today's needs without affecting the environment, so that future generations can meet their own needs.
Explain how humans today can use sources sustainably.	•Fishing quotas (limits to how much we can fish) - prevents certain types of fish from becoming extinct in certain areas due to their high demand. •Some laws insist that logging companies need to plant new trees to replace the ones they've cut down.
Explain why sunlight is a sustainable source.	•cannot be used for human activities •used to make food for natural ecosystems - like plants. •provides sustainable agriculture - sunlight can be used to power equipment like heating and lighting in greenhouses and irrigation systems.
List some of the decisions that some communities have to make in terms of conserving ecosystems.	•decide on whether causing damage to the ecosystem to get resources, or protecting an ecosystem but getting few resources from it e.g population growth means more people have to be fed
Why do these decisions cause tension?	•people have to decide whether it is worth it or not, whether to risk damaging the ecosystem, and increase food production, or to protect the ecosystem, and get few, to no resources.

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	Created by Czean Holgado about 7 years ago