OCR 21st Century Science B7 revision cards

HideShow resource information
  • Created by: isis
  • Created on: 10-06-13 14:56
What are the functions of the skeleton?
1. Support the body. 2. Store minerals (calcium, phosphorus) 3. Make red blood cells, platelets and some white blood cells. 4. Allow for movement. 5. Protect internal organs (pelvis protect reproductive organs)
1 of 244
How does exercise change bones?
Weight bearing exercises (jogging) stimulate bone growth increasing it's density. Inactivity makes bones less dense and weaker
2 of 244
What are the two types of joints?
Ball-and-socket joints and hinge joints.
3 of 244
What are ball-and-socket joints like?
They are very versatile and can move in every direction. They are at you hips and shoulders.
4 of 244
What are hinge joints like?
They can only move in two directions - backwards and forwards. They are at your knees and elbows.
5 of 244
What are tendons?
A tough band of elastic tissue attaching muscle to bone.
6 of 244
What are ligaments?
Bands of tough elastic tissue holding bones to each other. They hold bones in place and limits how far they can move.
7 of 244
What is cartilage?
A smooth protective surface that covers the bone ends providing easy movement. It forms a rubbery shock-absorbing coat, it stops bones from damaging each other.
8 of 244
What does synovial fluid to?
it lubricates and nourishes the tissues in the joint capsule.
9 of 244
What does the synovial membrane do?
It lines the joint capsule and secretes synovial fluid.
10 of 244
What is meant by the terms antagonistic pair?
Muscles that work opposite each other. (biceps and triceps)
11 of 244
What might be asked before a person starts a new exercise regime?
If they or anyone in their family suffers from certain medical conditions, if they have suffered any injuries (especially to back and joints) if they are on any medication, what their lifestyle is like.
12 of 244
What fitness tests could be carried out to collect baseline data?
Heart rate, Blood pressure, Recovery period, Proportion of body fat and BMI
13 of 244
What happens to the data collected as someone gets fitter compared to their baseline data?
Heart rate decreases, Blood pressure reduces, Recovery period shortens, Proportion of body fat decreases and BMI will fall.
14 of 244
What does accurate mean?
An accurate instrument or procedure gives a 'true' reading.
15 of 244
What does calibrated mean?
It means that the measurement from the equipment under test is compared to the measurement of equipment that is know to be of the correct standard.
16 of 244
What dies repeatable mean?
If you get similar results with each re-run of an experiment
17 of 244
What must be done when measuring your heart rate?
Make sure you use your fingers rather than a thumb as it has its own pulse which might confuse you.
18 of 244
What must be done when measuring blood pressure?
Make sure that the equipment is not damaged or has low battery power. Always measure your blood pressure sitting down with your arm at chest height as raising your arm reduces the pressure. Remember that if you are stressed the values will be higher
19 of 244
What must be done when measuring revovery period?
Repeat calculations and use an average.
20 of 244
What must be done when measuring body fat?
Take care reading the scales and make sure that you are reading the correct units(not imperial units) and take the reading at the right place on the scale.
21 of 244
What must be done when measuring the BMI?
Remember that your mass will vary at different times of the day and so always measure your body at the same time each day. Make sure that the source for graphs or table is reputable. Remember there are different graphs for men, women and children.
22 of 244
What are the symptoms of a sprained ligament?
Redness and swelling, surface bruising, difficulty walking, dull, throbbing ache or sharp, cramping pain.
23 of 244
What does RICE stand for?
Rest, ice, compression and elevation.
24 of 244
What does rest involve in terms of the RICE method?
Immobilising the injured part.
25 of 244
What does ice involve in terms of the RICE method?
It acts as an anaesthetic, reduces swelling and slows the flow of blood to the injured area. To avoid directly damaging the tissue, the ice is applied indirectly for up to 20 mins at a time with 30 mins between applications,
26 of 244
What does compression involve in terms of the RICE method?
It involves wrapping a bandage round the injured part to reduce swelling. The bandage should be snug but not too tight so that it cuts off the blodd supply.
27 of 244
What does elevation involve in terms of the RICE method?
It means raising the injured limb in order to reduce the swelling by helping to keep excess fluid away from the damaged area.
28 of 244
What follows the RICE method and what do these involve?
Simple stretching exercises help regain mobility but only when swelling stops. Aerobic exercising of injured part is not restarted until it has regained at least 75% of the previous strength level and then only moderately.
29 of 244
What happens when a ligament tears?
It may tear with a popping sound , leaving the joint painfully bruised and very hard to bend. There might be a dent where the ligament is torn.
30 of 244
What can happen to tendons is sports which involve a lot of jumping such as basketball?
Tendons can stretch, become inflamed, and even snap like a worn-out elastic band.
31 of 244
What is a dislocation?
It is when the bone slips out of the joint.
32 of 244
In what sport are knee dislocations common and how do they happen?
Gymnastics. Floor routines put a lot of force on the the joints and if they land off balance their kneecap can become dislocated.
33 of 244
What sort of sports are shoulder dislocations common?
Contact sports such as rugby.
34 of 244
What sort of injuries are common in footballers?
Joint injuries.
35 of 244
At rest how many times a minute does your heart beat?
About 60-80 time per minute.
36 of 244
What is blood plasma?
It is mainly water and is the pale yellow liquid that cells float in.
37 of 244
What does blood plasma do?
It transports a range of materials including nutrients such as glucose, antibodies, hormones and waste such as carbon dioxide and urea. It gives blood its bulk and helps distribute heat around the body.
38 of 244
What are the three main types of cells that float in plasma?
Red blood cells, white blood cells and platelets.
39 of 244
What is the function of red blood cells?
To transport oxygen around your body.
40 of 244
What is the function of white blood cells?
To fight infection. They produce antibodies, and engulf and digest microorganisms by phagocytosis.
41 of 244
What is the function of platelets?
They play an important role in blood clotting at an injury site. They stick to the edge of a cut and send out chemicals that trigger a series of reactions that form a clot at the cut site.
42 of 244
How are red blood cells adapted to their function?
They have no nucleus which allows more space for haemoglobin. They have a biconcave shape which gives the cells a large surface are making the diffusion of gases very efficient, This shape also gives cell flexibility to squeeze through tiny capillari
43 of 244
What sort of circulatory system is the human heart and why do we call it this?
Double circulatory system because the blood passes through the heart twice on every circuit of the body.
44 of 244
Where does blood from the body enter and through what vein does it enter the heart?
It enters the right atrium through the vena cava, which is the main vein from the body.
45 of 244
What happens to the blood after it enters the right atrium?
It is pumped out of the right ventricle towards the lungs through the pulmonary artery.
46 of 244
In the lungs what happens to the blood?
It picks up blood and becomes oxygenated.
47 of 244
What happens after blood has been oxygenated at the lungs?
It enters the left atrium through the pulmonary vein and passes in to the left ventricle. It then gets a harder pump which carries the blood around the body through the aorta.
48 of 244
What happens to the blood when it carried around the body?
It gradually gives up its oxygen to the cells and becomes deoxygenated. It then returns to the right atrium.
49 of 244
Why is the wall thickness of the right and left ventricle different?
The left ventricle has a thicker wall because the blood needs to be at a higher pressure so that it can be pumper around the whole of the body. Whereas the right ventricle only needs to pump it to the lungs and so needs a lower pressure.
50 of 244
What doe the different valves in the heart do?
The valves between the atrium and ventricle stop blood flowing backwards from the ventricles into the atria. The valves between the ventricle and arteries stop blood flowing backwards from the arteries into the ventricles.
51 of 244
What happens in capillaries?
They are where chemical in the body's cells and in the blood are exchanged.
52 of 244
How are capillaries adapted to their function?
Capillary walls are one cell thick and very porous making diffusion much more efficient.
53 of 244
What happens when blood enters a capillary bed from an artery?
The blood is at high pressure and is squeezed out of the capillary forming a liquid called tissue fluid.
54 of 244
What is the purpose of tissue fluid?
Tissue fluid contains all the dissolved raw materials being carried by blood plasma, including glucose and oxygen. These chemicals diffuse into the cells. Wast products from cells, including carbon dioxide and urea diffuse out into the tissue fluid.
55 of 244
Why does tissue fluid move back into capillaries towards the end of the capillary bed?
As the blood passes through the capillary bed the pressure drops. Plasma stops being squeezed out, and tissue fluid moves back in.
56 of 244
What is one way in which your body gains heat and why?
Respiration because some of the energy released from breaking down glucose warms your body.
57 of 244
What two things must be balanced to keep your body temperature steady?
Energy gain must be balanced by energy loss.
58 of 244
What should your core temperature be?
Between 36 degrees centigrade and 37.5 degrees centigrade.
59 of 244
Why is not all of your body the same temperature?
Your extremities are cooler than your core because they have a larger surface area compared with their size and so lose energy to the environment faster than the main parts of your body.
60 of 244
Where are temperature receptors that detect blood and what else does this do?
The area of the brain called the hypothalamus, it is also the processing centre for temperature control.
61 of 244
How does shivering warm you up?
Muscles contract quickly and so respire faster to release the energy for this movement,
62 of 244
How does hair raising warm you up?
The erector muscles make hair stand on edge, which traps a layer of warm air.
63 of 244
What are some warming behaviours and why do they warm you up?
Exercise- respiration, More clothes- reduce heat loss, move to a warm place or having a hot drink will also warm you up.
64 of 244
How does vasoconstriction warm you up?
The muscles in the walls of blood vessels near the surface of the skin contract. Less blood flows near the surface of the skin, so less energy ow lost to the environment.
65 of 244
How does vasodilation cool you down?
Tee blood vessels near the surface of skin are filled with blood as they relax. Energy from the warm blood is transferred down the temperature gradient to the environment.
66 of 244
Describe the process of vasodilation.
Temperature receptors detect a rise in temperature, The hypothalamus receives impulses from the temperature receptors. Nerve impulses to muscles in blood vessels are stopped. Vasodilation takes place.
67 of 244
Describe the process of vasoconstriction.
Temperature receptors detect a fall in temperature, The hypothalamus receives impulses from the temperature receptors. Nerve impulses are sent to muscles in blood vessel walls. Vasoconstriction takes place.
68 of 244
How does sweating cool you down?
Water molecules in sweat gain energy from your skin, Soon they move quickly enough to evaporate. This cools you down.
69 of 244
What are some cooling behaviours and why so they cool you down?
Taking a break from exercise or moving to the shade will let your body temperature recover. Removing clothes- increases rate of heat loss, wet your skin or fan yourself- evaporation.
70 of 244
What causes type 1 diabetes?
Some people develop it when they are young when their pancreas suddenly stops making enough insulin.
71 of 244
What are the symptoms of type 1 diabetes?
Thirst and the production of large volumes of urine containing sugar.
72 of 244
What happens if your blood sugar levels rise too high or fall too low?
To high - drowsy, too low- may go into a coma.
73 of 244
How is type 1 treated?
People need several daily injections of insulin to control their blood sugar level. They also have to be careful about what they eat, to match their sugar intake with their lifestyle.
74 of 244
What causes type 2 diabetes?
People with a poor diet, inactive lifestly or who are obese may develop type 2 diabetes in middle age. This is because the body gradually stops making enough insulin for your needs or the cells can't use the insulin properly.
75 of 244
What are the symptoms of type 2 diabetes?
Thirst, frequent urination, tiredness and weight loss.
76 of 244
Whatare some of the problems associated withe type 2 diabetes?
Over time type 2 diabetes can cause 'hardening of the arteries' which can lea to heart attack, kidney damage, or sight problems-where blood vessels in the retina are involved.
77 of 244
How is type 2 diabetes treated?
People withe type 2 diabetes need to take regular, moderate exercise to control their blood sugar levels. They have to eat carefully and plan their diet, so that sugar is released steadily.
78 of 244
What should all diabetics do when exercising?
Make sure that they have a sweet snack or sugary sports drink nearby in case their blood sugar levels fall to low.
79 of 244
What can exercise do?
It strengthens muscles, improves co-ordination, develops self-discipline, helps maintain a healthy body mass and bring you a lot of enjoyment and rewards.
80 of 244
What illnesses can an unhealthy diet lead to?
Heart disease, diabetes, obesity, tooth decay, bowel cancer and anorexia.
81 of 244
What is one reason why people in different countries have different rates of illness?
Some of the differences can be explained be differences in food. For example people in Japan people eat less red meat and more fish than people in the UK. Rate of heart disease in Japan is lower than in the UK.
82 of 244
Why is there a difference in the rate of bowel cancer between developed and developing countries?
Diets in developing countries are often high in fibre so food passes quickly through the digestive system. In developed countries people eat more refined, processed food, they take longer to travel through so any toxins are in contact for longer.
83 of 244
What sort of foods increase the risk of cancer?
Alcohol, processed and red meat and salt.
84 of 244
What sort of foods decrease the risk of cancer?
Fruit and vegetable, fibre and dairy products.
85 of 244
What removes sugar from the blood?
The hormone insulin.
86 of 244
Why are foods that are high in fibre and comlex carbohydrates better for you?
These sort of foods are digested slowly and their sugars are released gradually into your blood stream so there is not a lot of sugar being added to your body at one.
87 of 244
What is a 'risk factor'?
These are things that increase your chance of becoming ill.
88 of 244
What is a linear system?
A system based on the take-make-dump model.
89 of 244
What is meant by sustainable?
Using the Earth's resources in a way that can continue in the future, rather than destroying them.
90 of 244
Why can linear systems only continue for a short time?
Fossil fuels are running our, natural resources are being used more quickly than they are being replaced, making products uses a lot of energy from fossil fuels and creates a lot of waste, waste from broken/worn-out products, waste can be harmful.
91 of 244
What are some of the problems associated with waste?
Waste can be harmful to people and wildlife, and can stay in the environment for a long time and waste means that rare resources such as metals are spread thinly around the environment, so they van't be reused easily.
92 of 244
What is a closed loop system?
A system with no waste-everything is recycled.
93 of 244
Why do closed-loop systems have no waste?
It is because output from one part of the system become the input for another part, so X's waste becomes Y's food. E.g plant waste is eaten by snails, faeces from snails is broken down by microorganisms they release nitrogen and phosphorus- to plants
94 of 244
What are natural closed-loop systems called?
Ecosystems, which are living organisms plus their non-living environment working together, such as lakes,woodlands, grasslands, beaches and coral reefs.
95 of 244
In natural ecosystems what is some of the waste?
Oxygen, carbon dioxide, and dead organic matter.
96 of 244
What are some examples of how barn owls live in a closed-loop system?
Droppings- broken down by microorganisms, releases nitrates and phosphates- plants take up for growth. Pellets- Bones dissolve in rain. Clothes moth larvae eat fur. Dead owls-burying beetles lay eggs in bodies and larvae eat flesh. Baby owl week e
97 of 244
What is a human community that still lives in a closed-loop system?
The Maasai people.
98 of 244
Why are Maasai villages sustainable?
Their huts are made from sticks, grass, mud, ash and dung. They are fully biodegradable and therefore sustainable. Their village is surrounded with a fence made of thorny branches this is also biodegradable.
99 of 244
Why does the Maasai diet cause so little damage to the environment?
They do not hunt game or birds and they do not eat much meat. This means they are not removing as much from the ecosystem. They drink milk more of which can be produced. When they die, their bodies are left out for scavengers, so they become food.
100 of 244
What is dead organic matter (DOM)?
It includes things such as fallen branches, leaves, petals and fruits. It is any material that was once part of a living organism, It also includes waste material from animals such as faeces and bodies,
101 of 244
What organisms are waiting for DOM?
Worms nibble leaves and grind then up in their gut, the are digested by enzymes. Threads of fungi in the soil release digestive enzymes that break down DOM. Dung beetles roll up faeces into pellets, then bury the pellets and lay eggs in them.
102 of 244
Why are bacteria in the soil very important?
Without bacteria there would be no recycling of reactants such as carbon and nitrogen in ecosystems.
103 of 244
What types of bacteria are involved in the nitrogen cycle?
Nitrogen-fixing bacteria. Decomposing bacteria. Other bacteria convert ammonium ions into nitrates, In anaerobic soil bacteria change nitrates into nitrogen gas.
104 of 244
How are bacteria involved in the carbon cycle?
Bacteria break down carbohydrates in DOM. The carbohydrates provide glucose for respiration, this releases carbon dioxide into the atmosphere,
105 of 244
Why is a lot of pollen, petals and fruit produced by plants?
It increases the chance that some will reach other flowers and pollinate them. They are maximising their chances of reproducing successfully. Plants compete with each other to attract pollinators, Lots of big bright petals attract many pollinators.
106 of 244
Why do animals produce lots of eggs and sperm?
Eggs contain a lot of protein, so many are eaten by predators before the eggs hatch. Young hatchlings are also eaten in large quantities. A male producing many sperm cells increases his chances of fathering offspring.
107 of 244
What is a stable ecosystem?
An ecosystem that renews itself and does not change.
108 of 244
Why are natural systems not wasteful?
Any DOM decomposes and the materials are recycled. Water, nitrogen, carbon and oxygen simply circulate around the ecosystem. Natural systems do not need to worry about wasting energy because they have a constant source-the Sun.
109 of 244
Why are most ecosystems not perfect closed loop systems?
When birds migrate in the winter, not all of the birds will return in the spring. So some material is permanently removed from their summer homes. Rivers carry branches, leaves, nutrients and silt away. Coral reefs grow larger as they take minerals.
110 of 244
What are ecosystem services?
Life-support systems that we depend on for our survival.
111 of 244
What does deforestation mean?
Cutting down and clearing forests leaving bare ground.
112 of 244
Why is soil erosion a problem caused by deforestation?
The roots of trees reduce soil erosion by holding the soil together.However, deforestation mean that this no longer happens causing rain to fall on bare ground and washes away the soil. The eroded soil silts up rivers and blocks drains.
113 of 244
What is another problem associated with deforestation?
Before deforestation water evaporation from the forest canopy generated clouds and rain and cooled the air. However, deforestation means this no longer happens.
114 of 244
What can be done to protect and restore natural closed-loop systems?
Forests can be replanted or protected and flood water can be diverted into wells to restore underground water levels.
115 of 244
Why is ploughing a problem?
It damages earthworms this means the soil becomes compacted and crops do not grow so well because earthworms play an important role in breaking down DOM, and mixing and aerating the soil.
116 of 244
What is a solution to the problems caused by ploughing?
Direct drilling is being tested. This is planting seeds directly into the soil without ploughing first. For example **** seed can be planted directly into wheat stubble.
117 of 244
What are the advantages of direct drilling?
It means that the worms are not damaged and the soil is more fertile. It shows how we can grow crops without destroying the ecosystem services we depend on.
118 of 244
Where does waste come from in our take-make-dump linear lifestyle?
From households, industry and burning fossil fuels.
119 of 244
What does non-biodegradable mean?
Waste materials that microorganisms cannot break down.For example, glass, synthetic fabrics, some pesticides and many plastics, This means that they stay around in the environment for a very long time.
120 of 244
What are the problems with plastics in the sea?
They can be eaten by sea birds, fish and turtles. They cannot digest the plastic, so their guts get blocked. Wave action breaks some plastics down into fine granules. Small animals filter plastic granules from the water instead of their normal food.
121 of 244
What are the problems with heavy metals?
Shiny paper from magazines and printed cardboard contains heavy metals. These accumulate in ecosystems. Heavy metals have been linked to birth defects in humans.
122 of 244
What are the problems with dioxins?
Bleached paper, cardboard and certain plastics contain chlorine. Chemical called dioxins are made when these bleached products are burned with other waste. Exposure to dioxins is associated with cancer, birth defects and problems with immune system.
123 of 244
What is bioaccumulation?
Build-up of chemicals in organisms as the chemicals travel through the food chain.
124 of 244
What is an example of bioaccumulation?
A vole takes in a small amount of pesticide in its food The pesticide is stored in vole's body-it can't be broken down. When an owl eats a vole all the pesticide goes in. Eventually enough to make infertile or kill owl.
125 of 244
How do heavy metals and dioxins bioaccumulate in humans?
Heavy metals and dioxins that are washed into rivers and the sea are concentrated in plankton, then fish and sea birds. If humans eat fish that have accumulated metals such as mercury, the levels can be high enough to cause concern.
126 of 244
What is biomass?
Biomass is any biological substance we harvest, such as grass, crops, wood, fish and game.
127 of 244
Why are ferilisers needed?
Agriculture involves removing biomass from fields. Therefore soil nutrients need to be replaced and to do this fertilisers are needed.
128 of 244
How could agriculture become a closed-loop system?
Human faeces and urine would need to be returned to the fields as fertiliser.
129 of 244
What are the risks associated with using human waste being used as fertilieser?
It risks introducing high levels of toxins into food crops by bioaccumulation. It could also transmit infectious diseases.
130 of 244
What alternative ways could help make agriculture a closed-loop system?
Using other biodegradable organic wastes such as animal manure, unwanted food and plant waste can be used a fertilisers.
131 of 244
What is eutrophication?
The build up of nutrients in water.
132 of 244
Where do the nutrients that cause eutrophication come from?
Nutrients from non-organic fertilisers often wash off fields and into rivers and lakes. Faeces and uneaten food from fish farms also add nutrients to water.
133 of 244
What do the added nutrients cause?
They cause algae to grow rapidly. The water goes green in an algae boom. The algae soon die and decay-bacteria, in the water. Bacteria take oxygen from water. The oxygen levels fall killing animals and aquatic plants that would normally add oxygen.
134 of 244
Why are organic fertilisers and manure more sustainable?
They break down more slowly. Nutrients are released at the rate the crop can absorb them, so they do not get washed away in the rain,
135 of 244
What other ways can agriculture be made more sustainable?
Crop rotation uses plants, such as clover, with nitrogen-fixing bacteria in their roots. Leaving a field with a fallow crop of clover one every few years replenishes the soil with nitrogen compounds.
136 of 244
What does biodiversity mean?
The great variet of living things, both within a species and between different species.
137 of 244
What is intensive agriculture?
Farming with high inputs of fertiliser and pesticides and high productivity. In the long term it is unsustainable and a linear system.
138 of 244
What is an example of intensive agriculture?
Calfornia's almonds. California produces 80% of the world's almonds. Lots of fertilisers have to be added as well as pesticides because pest insects and fungi have fe natural enemies in an almond crop and so spread quickly doing a lot of damage.
139 of 244
What are the consequences of using pesticide in California's almonds?
The pesticides used kill pollinating insects, such as bees, in addition to the insect pests. This means that every year over a million bee hives are transported in to the Californian orchards. When they are finished the are moved to other crops.
140 of 244
Why does setting quotas not solve all of the problems associated with overfishing?
Politicians want to protect jobs and please electors- set higher than recommended quotas. Fishing has to be monitored and policed. If too many are caught fish are often dumped. Fishing fleet move to unprotected areas. More deep-sea fishing- damage
141 of 244
What other solutions are there to over fishing?
Fishing bans, such as the fishing ban for bluefin tuna, and fish farming (aquaculture), such as salmon farms.
142 of 244
What are the problems with fish farming?
It is not sustainable. Food must be added and dirty water removed. This linear system can cause environmental damage. Overfishing anchovies to provide food for salmon and polluting the local environment are two of the problems.
143 of 244
What might happen if a fishing ban is imposed too late?
Fish populations might not recover, other predators may move in and their position will have been taken. Newfoundland's cod fishery collapsed in 1992 and is still unfishable.
144 of 244
What is desertification?
Turning to desert.
145 of 244
What techniques have been developed in the Sahel to prevent desertification by reducing soil erosion?
Herds are moved from place to place to prevent overgrazing, Trees are not cut down in fragile areas. Acacia trees are planted as windbreaks. Thorny branches and rocks are used to reduce erosion in stream beds.
146 of 244
What technique is used to make the soil fertile?
Hundreds of small pits are dug in the dry season. Compost is placed in the pits and covered with soil. Termites and fungi live in the compost and make the soil fertile. When the rains arrive, water drains into the pits, making a seedbed for crops.
147 of 244
What is overgrazing?
Too many grazing animals, such as goats damaging the environment.
148 of 244
What are some of the problems with the modern day Sahel region?
The rains have been better and people have been tempted to use intensive linear-system farming methods, using fertiliser and pesticides . Some of the traditional methods have been lost
149 of 244
What is being done to help return the Sahel to a closed-loop system?
People are encouraged to plant native species as they are adapted to the dry conditions and to use better farming methods. Also using crop varieties could bring sustainable solutions.
150 of 244
What are some of the tensions between conservation and the needs of local people?
For example in India, rapid economic development and a growing population are putting pressure on tiger reserves. Conserving ecosystems is beneficial to humans, as it protects the ecosystem services they provide.
151 of 244
Why are tigers worth more dead?
Living tigers are undervalued and there is a huge market for dead tiger parts for traditional medicines.
152 of 244
What does a good tiger population mean?
Tigers are at the top of the food chain and a good population means that the whole ecosystem is healthy.
153 of 244
Why are tigers important?
They bring inspiration to many people. Tourists come to see them. Tiger reserves offer jobs to rangers and scientists. Without tigers fewer tourists would come, and the whole ecosystem would change.
154 of 244
What does ethical mean?
Non-scientific, concerned with is what is right and wrong.
155 of 244
What are primary forests?
A forest that has never been felled or logged.
156 of 244
Why are forests being cut down?
They cut down forests for timber, to provide grassland for cattle, and to grow palm oil, soya, and biofuels.
157 of 244
What does loss of forests cause?
It causes soil erosion, mud slides, silting of rivers, flash floods, loss of cloud cover, and drought. It also takes away a sustainable source of timber.
158 of 244
What are the consequences of biomass being removed?
It changes the natural closed-loop system to a linear system. Nutrients are taken away with the biomass. If crops are grown fertilisers are needed.
159 of 244
What does the sustainable use of timber mean?
It means replacing the trees and nutrients as quickly as they are taken away.
160 of 244
What is eco-labelling?
An eco-label shows that the timber was harvested from a sustainably managed forest. When we buy food we can check the label to see where and how it was produced.
161 of 244
What is a carbon sink?
A system taking carbon dioxide from the air and storing it, for example, a growing foret.
162 of 244
What else to forests do?
It also helps to restore soils and clean water supplies, The forest creates jobs through leisure and tourism.
163 of 244
What is cloud formation?
Evaporation of water, for example, from a forest, condensing into clouds.
164 of 244
Why must we we move quickly into a post-oil economy?
Fossil fuels are running out and burning fossil fuels is increasing carbon dioxide levels in the atmosophere.
165 of 244
Where does oil come from?
It comes from the dead bodies of minute plants and animals. They lived in the sea millions of years ago. They fell to the sea bed and were slowly covered by layers of sand and silt.Heat and pressure changed the dead biomass into oil.
166 of 244
What is fossil sunlight energy?
Sunlight energy stored as chemical energy in fossil fuels.
167 of 244
What is crude oil?
Oil straight from an oil well, not refined into petrol or diesel.
168 of 244
What is energy needed for?
Ploughing and planting crops, making fertilisers and pesticides, food processing and transport and distribution of food.
169 of 244
What does intensive farming cause?
It causes pollution, soil erosion, loss of biodiversity, and climate change. It is a take-make-dump, linear system.
170 of 244
What are the pre-oil farming methods used in many parts of the world?
Fields are cultivated using horses or oxen. The animals energy comes from biomass and not from oil. The animals' faeces enrich the soil. Crops are harvested and separated using hand tools,. Food is produced and consumed locally.
171 of 244
What are the problems with traditional methods?
They cannot produce enough food for the millions of people living in cities. Traditional methods also leave little time for other activities.
172 of 244
What are the advantages of using biofuels?
Many plants make oil in their seeds. These can be harvested and turned into biofuel. Biofuel is made from crops and is carbon neutral. The same amount of carbon dioxide fixed in photosynthesis is released when the biofuel is burnt.
173 of 244
What are the problems with biofuels?
Biofuels take land needed to produce food and forests, grasslands and other wild place are being lost to biofuel crops.
174 of 244
Why must the conditions inside fermenters be carefully monitored and controlled?
Fast-growing microorganisms use up a lot of oxygen and nutrients and the produce toxic waste products and heat.
175 of 244
What are the benefits of a fermenter?
Rapid reproduction, presence of plasmids simple biochemistry, lack of ethical concerns in their culture and the ability to make complex molecules?
176 of 244
How is the presence of plasmids a benefit?
New genes can be introduced into the plasmids in the lab so the bacteria make what we want.
177 of 244
How is the simple biochemistry a benefit?
The way that bacteria work is well understood, so the nutrients and growth conditions in a bioreactor can be controlled for optimum production.
178 of 244
How is the lack of ethical concerns in their culture a benefit?
There are no animal welfare issues; many processes are similar to age-old brewing and any bacteria are usually removed from the final products.
179 of 244
How is the ability to make complex molecules a benefit?
Bacteria can make complex antibodies, food additives, and hormones that can't be easily synthesised in the lab.
180 of 244
What is an example of antibiotics being created in fermenters?
When the fungus Penicillium grows in a tank of nutrient solution, the antibiotic penicillin is secreted into the solution. It is easy to extract the antibiotic for use as a human medicine.
181 of 244
Why are enzymes from microorganisms very important in food production?
They are used to control the flavour, aroma, texture, or rate of production for many f
182 of 244
What is rennet?
It is an extract from calves' stomachs that helps young mammals digest their mother's milk. They cause milk to form sold lumps so it moves more slowly through the gut. It is used to make some kinds of cheese.
183 of 244
How have scientists made 'vegetarian' cheese?
One of the enzymes in rennet is called chymosin. Scientists have developed strains of fungus that make chymosin. This can be used to make 'vegetarian' cheese.
184 of 244
Other than cheese, what else are enzymes used for?
They are added to detergents to make 'bio' laundry liquids and powders. These enzymes digest the fats, carbohydrates, and proteins in the stains in our clothes. 'Bio' detergents often give good results at lower temperature.
185 of 244
What is the enzyme being used to make biofuels?
Wood is made up of plant cells will cellulose walls. Tough fibres called lignin fill the spaces in the cell walls and make it hard to digest. Have developed a commercial way to make lignocellulase that breaks down lignin and cellulose.
186 of 244
How does the enzyme used to make biofuels?
Lignocellulase can turn woody stalks and leaves into sugars, Ethanol can be produced using waste plant material instead of useful crops.
187 of 244
Why can microorganisms be grown for food?
Some microorganisms produce proteins that are similar to the proteins in fish or soya beans. They can be grown on simple nutrients, and they can reproduce rapidly in the right conditions. This means they could be used as food.
188 of 244
What is a food that can be grown from microorganisms?
Quorn(a single-celled protein) is made from a fungus that grows as a cluster of interwoven fungal threads. The threads are extracted from a fermenter, pressed together, and processed to match the taste and texture of meat.
189 of 244
What are plasmids?
Small circle of DNA found in bacteria. Plasmids are not part of the bacterium's main chromosome.
190 of 244
What is genetic modification?
Altering the characteristics of an organism by introducing the genes of another organism into its DNA.
191 of 244
What is one example of genetic modification?
Many drugs used to treat illnesses are proteins. Before GM, insulin to treat diabetes was extracted from animals such as pigs, This worked but pig inslulin could produce harmful side effects. GM bacteria can be made to produce human insulin.
192 of 244
What does genetic modification mean for plants?
GM means developers can *** new genes to plants. These genes code for new proteins to give the plant desired properties. They can be made resistant to some herbicides for example.
193 of 244
What is a vector?
A method of transfer. Vectors are used to transfer genes from one organism to another.
194 of 244
Why are plasmids used as vectors to modify bacteria?
Plasmids are easier to manipulate than a bacterial cell's main chromosome. They are small and they move easily in and out of celss.
195 of 244
How to scientists make it easy to select genetically modified cells?
They put a second gene into the plasmid. For example, there is a gene in jellyfish that codes for a green fluorescent protein and several genes make bacteria resistant to particular antibodies.
196 of 244
Why do scientists put a second gene in the plasmid?
It is because not all cells in a population of bacteria will take in the added plasmid and they want to be able to identify the ones with the plasmid in.
197 of 244
What are the steps to produce human insulin from bacteria?
Isolate the gene and make copies of it. Make a modified plasmid that contains the gene and another gene that gives resistance to an antibiotic. Add the modified plasmid to a population of bacteria. Treat the population with the antibiotic.
198 of 244
What does treating the bacteria with the particular antibiotic do?
The bacteria that survive must contain the plasmid, so they will also make insulin. The next step is to grow these modified bacteria and the harvest the insulin.
199 of 244
What are bacteriophages?
They are viruses that can infect bacteria, Scientists use them as vectors to carry larger genes into bacterial cells.
200 of 244
Why are nematode worms are problem?
They are microscopic worms that live in the soil. They attack the roots of crops, taking nutrients from the plant and laying their eggs inside the tissues. They can reduce the yield and if there is a large infestation kill most of the crop.
201 of 244
What is the solutuion to the problems of the nematode worm?
Cystatins affeect insect digestion, so insects cannot eat parts such as their seeds. Researchers used the bacteria Agrobacterium as a vector to carry the extra cystatin gene into the plant's gentic material. It makes the roots indigestible.
202 of 244
What are some of the arguements against introducing herbicide resistance gene into a plant?
Added genes could make 'safe' plants produce toxins or allergens. Marker genes for antibiotic resistance could be taken up by disease organisms. It will cost farmers more to buy seeds of GM crops, so food costs will increase.
203 of 244
What are the counter arguments to intoroducing herbicide resistance gene into a plant?
Food-safeety organisations can check for these. The antibiotics are not used in medicine, so it wouldn't matter. Farmers may benefit from healthier crops and lower costs pf production
204 of 244
What is a probe?
It is a short length of DNA that attaches itself to complementary sections of DNA.
205 of 244
What is gel electrophoresis?
It is when fragments of DNA are placed in a gel with an electrical field across it.
206 of 244
How does gel electrophoresis work?
Fragments move through the gel at different rates, according to their size. Fragments of the same size move together and form a band. Radioactive probes latched on to minisatellite sequences and showed the bands as dark lines on X-ray film.
207 of 244
What is used instead of radioactove markers?
Safer fluorescent markers are used, which glow when stimulated by light. Computers interpret the patterns of bands in gels and produce a printout. Scientists no longer study and measure the gels directly.
208 of 244
What is DNA profiling?
A DNA profile is produced in the same way as a DNA fingerprint, but fewer gene probes are used, DNA profiling is used in forensic science to test sample of DNA left at crime scenes.
209 of 244
What are the first methods of genetic profiling?
DNA extracted from tissue sample. Double-stranded DNA in sample. DNA separated into single strands by gentle heating. Short sections of DNA with fluorescent markers are added-it is complementary to a target section n the original DNA.
210 of 244
What are the next methods of genetic profiling?
Complementary DNA binds if it matches the target sequence. Short sections of DNA are copied by multiple rounds of PCR, PCR products are separated by gel electrophorsis and show up as fluorescent bands.
211 of 244
What is the final step of genetic profiling/
A computer reads the gel and prints out a profil showing each band as a peak.
212 of 244
What are the uses of genetic testing?
It can show family relationships between people. For example, it can show that a particular man is the father of a child. It is also used to identify human remains and can identify criminals.
213 of 244
How is it used in relation to genetic disorders?
It is possible to find out if a gene in a DNA sample is a variant of the gene that is linked to the genetic disorder. This makes it possible to identify affected individuals or carriers of a disorder with a genetic component.
214 of 244
How is DNA profiling used in zoos?
DNA profiling is used to find out how closely related animals are. This information is used to plan breeding programmes in zoos. It can also match individual animals to DNA from crime scenes or to identify ownership.
215 of 244
What is a gene probe?
A short piece of single-stranded DNA used in genetic test. The gene probe has complementary bases to the allele that is being tested for.
216 of 244
What does PCR stand for?
Polymerase chain reaction.
217 of 244
What is PCR used in?
Forensic science when the amount of DNA found at crime scene is very small, to copy a gene for genetic modification, to make gene probes, to make many copies of a region of interest so that it can be studies further.
218 of 244
What are some of the disadvantages of knowing your gentic profile?
It could be possible for employers and insurance companies to use genetic testing information to make decisions affecting people''s lives.
219 of 244
What is nanotechnology?
Technology based on particles that are less than about 100nm in at least one dimension.
220 of 244
What have manufactures recently developed?
Plastic with tiny particles of silver embedded in it. This can be used for making food storage boxes and film wraps for food. The silver particles reduce contamination of the food by microorganisms.
221 of 244
What does some plastic food wrapping do?
It changes colour when antibodies in the film react with bacteria in the food, nanoparticles in the film react to changes in the amount of oxygen in the packet, which is a sign that the wrapping could be damaged and fruit ripens and releases gases.
222 of 244
What can nano-sized particles of silver do?
They can be absorbed into animal cells, where nanosilver particles react with cell contents and releases silver ions. They are similar in size to sodium ions and disrupt normal cell activities.
223 of 244
What are solutions of silver salts used for?
They can be used directly for their antibacterial effect (contain silver ions). But ions in silver salt solution react with other molecules before they can be absorbed,
224 of 244
What are some of the risks of using nanotechnology?
They may behave in unexpected ways or be toxic to humans. For example, there have been concerns that silver in food packaging could leak out into landfill or into waterways and cause environmental damage.
225 of 244
What does differentiated mean?
A differentiated cell has a specialised form suited to its function. It cannot change into another kind of cell.
226 of 244
What are stem cells?
Unspecialised animal cells that can divide and develop into specialised cells.
227 of 244
How are stem cells used to treat leukaemia?
Bone marrow transplants have been used. Bone marrow contains stem cells that divide and differentiate to make 8 different kinds of blood cell. The new bone can make healthy blood.
228 of 244
What is tissue culture?
Stem cells are grown in a special growth solution containing proteins and sugars to stimulate growth, Skin culture produces a thin layer of skin cells that can be used as a skin graft to treat burned skin.
229 of 244
How could stem cells be used to treat spinal injuries?
Potentially stem cells could be used to repair damaged spinal tissue, which could restore movement to people paralysed by spinal cord injuries.
230 of 244
What else might stem cells be able to be used for in the furture?
It may be possible to repair brain damage, such as that caused by Parkinson's disease or Alzheimer's. Stem cells could be used to treat some kinds of diabetes, particularly in young people. if the cells can develop in the pancreas to produce insulin.
231 of 244
Where in our bodies are stem cells found?
There are stem cells in our skin, blood. and bone marrow.
232 of 244
What is another source of stem cells?
Umbilical cord blood. Each baby born could provide some stem cells for research and future treatments. The many embryos left over from fertility treatments are another potential source of stem cells.
233 of 244
What does the area of your heart called the pacemaker do?
It controls the muscle contractions, using electrical signals. This makes sure the heart muscle contracts in the right sequence and pace. It keeps your heart beating at a slow and steady pace when resting and at a higher rate when exercising.
234 of 244
What happens when you have a heart attack?
Blood vessels providing the heart with oxygen and food get blocked. for example, by fatty deposits in their lining. Parts of the heart muscle receives no blood and the muscle tissue quickly dies.
235 of 244
How is a heart valve replaced?
A surgeon connects the patient's blood supply to a heart-lung machine. Then the surgeon stops the heart, cuts it open and replaces the damaged valve.
236 of 244
What is the main disadvantage of a tissue transplant?
The immune system causes rejection of the transplant. This happens because our immune system sees the new tissue as foreign, and attacks it as if it wee an invading bacteria or virus.
237 of 244
What is an example of biomedical engineering?
You could use an artificial valve that has been engineered to do the job.
238 of 244
What are the disadvantages of biomedical engineering of heart valves?
Cause damage to blood cells and make regular clicking noises as the valve closes.
239 of 244
What must the materials for replacement body parts be lik?
They have to be resistant to wear and tear, made of materials that do not corrode in the body, and do not stimulate the body's rejection systems. This avoids patients having to have regular operations to replace worn out valves,
240 of 244
What happens if your heart loses its natural rhythm?
It might feel strange or it might make exercise difficult.
241 of 244
What can artificial pacemaker do?
It can monitor your heart rate and stimulate the muscle to contract in a regular rhythm.
242 of 244
What work some scientists done relating to stem cells and the heart?
Used stem cells to develop muscle tissue in the laboratory, These muscle fibres contract and relax regularly, like a beating heart.
243 of 244
What can the new developments involving stem cells lead to?
If cells can be encouraged to develop in the same way inside a heart, it might be possible to repair the damage caused by a heart attack. Clusters of these cells could be used as a natural pacemaker.
244 of 244

Other cards in this set

Card 2


How does exercise change bones?


Weight bearing exercises (jogging) stimulate bone growth increasing it's density. Inactivity makes bones less dense and weaker

Card 3


What are the two types of joints?


Preview of the front of card 3

Card 4


What are ball-and-socket joints like?


Preview of the front of card 4

Card 5


What are hinge joints like?


Preview of the front of card 5
View more cards



so helpful thanks


yolo, yolo ,yolo, swag, yolo, swag, swag ,yolo.


Wow these are amazing...really helped before the exam thanks :)

Similar Biology resources:

See all Biology resources »See all resources »