B7- Further Biology

Question 1

Red blood cells?

Answer 1

These transport oxygen from the lungs to the rest of the body. They don’t have a nucleus but they have lots of haemoglobin (a substance that binds with oxygen)

Red blood cells have a biconcave shape to give them a large surface area for exchanging oxygen.

Question 2

Plasma?

Answer 2

This is a liquid that carries nutrients (e.g. Glucose & amino acids) , antibodies,hormones and waste (e.g. Carbon dioxide and urea)

Question 3

White blood cells?

Answer 3

Theses help to fight infection by protecting your body against attack from microorganisms.

Question 4

Platelets?

Answer 4

These are small fragments of cells that help the blood to clot at the site of a wound.

Question 5

Double circulatory system?

Answer 5

• The first one pumps deoxygenated blood to the lungs to take in oxygen. The blood then returns to the heart.
• The second one pumps oxygenated blood around the body. The blood gives up its oxygen at the body cells and the deoxygenated blood returns to the heart to be pumped out to the lungs again.

Question 6

Diagram of heart?

Answer 6

• The right atrium of the heart receives deoxygenated blood from the body (through the vena cava)
• The deoxygenated blood moves through to the right ventricle which pumps it to the lungs (via the pulmonary artery)
• The left atrium receives oxygenated blood from the lungs (through the pulmonary vein)
• The oxygenated blood then moves through to the left ventricle which pumps it out round the whole body (via aorta)
• The valves in the heart prevent the back flow of blood- veins also have valves for this reason.
• There are two coronary arteries which supply the heart muscle cells with blood.
• The left ventricle wall is thicker than the right as it has to pump blood all the way around the body. The aria have thinner walls as they only pump blood to the ventricles.

Question 7

Chemicals are exchanged between cells & capillaries?

Answer 7

• Arteries branch into capillaries which are small blood vessels.
• They have permeable walls so substances can diffuse in and out.
• Networks of capillaries in tissue are called capillary beds.
• As blood passes through capillary beds small molecules (e.g. Water,glucose,oxygen) are forced out of the capillaries to form the tissue fluid which surrounds the cells. These substances can then diffuse out of the tissue fluid into the cells.
• Waste chemicals (e.g. Carbon dioxide and urea) diffuse out of the cells into the tissue fluid then into the capillaries.
• The tissue fluid allows cells to get the substances they need and get rid of waste without a capillary supplying every single cell.

Question 8

Skeleton?

Answer 8

The job of a skeleton is to support the body and allow it to move- and protect vital organs.

Fish,amphibians,reptiles,birds and mammals are all vertebrates. They have backbone and an internal skeleton.

Other animals (e.g. Insects) have their skeletons on the outside.

Question 9

Joints?

Answer 9

• The bones at a joint are held together by ligaments. Ligaments have high tensile strength and slightly elastic. This means they help stabilise the joints but allow movement.
• The ends of the bones are covered with a smooth layer of cartilage to reduce friction between the bones. Cartilage can be compressed so it acts as a shock absorber.
• Membranes at some joints release oily synovial fluid to lubricate the joints allowing them to move easily by reducing friction.

Question 10

Muscles?

Answer 10

• Bones are attached to muscles by tendons.
• Muscles move bones at a joint by contracting.
• Tendons can’t stretch so when a muscle contracts a tendon pulls on the bone, transmitting the force from the muscle to the bone.
• Muscles can only pull on bones to move a joint but they can’t push. This is why muscles usually come in pairs. (Called antagonistic pairs)
• When one muscle in the pair contracts the joint moves in one direction. When the other muscle contracts it moves in the opposite direction.

Question 11

What does being “fit” mean?

Answer 11

Being fit is a measure of how well you can do physical activities.

Question 12

What do fitness practitioners need to know?

Answer 12

• Health problems- they need to know symptoms to health problems that could affect the persons ability to exercise.
• Current medication- the medication can affect the persons ability to exercise. (E.g. Making the drowsy)
• Previous fitness treatments- to know what has or hasn’t worked.
• Lifestyle factors- (e.g. Smoking or drinking)
• Family medical history- illness can run in the family. So it’s important when designing a regime.
• Physical activity- so the practitioner can plan a challenging programme that won’t injure the client.

Question 13

Recovery period??

Answer 13

• When you’re not exercising your heart rate and blood pressure are at their resting levels.
• During exercise your heart rate and blood pressure increase.
• When you stop exercising your blood pressure and heart rate return to their resting levels.
• The time it takes for this to happen is called recovery period.
• The fitter you are the shorter your recovery time.

Question 14

How can fitness be measured?

Answer 14

• Your body mass index (BMI) is based on your height and mass. It’s used as an indicator of your fitness.
• BMI isn’t the most accurate indicator of fitness (as muscle can be dense and is more heavier than fat)
• Another indicator is proportion of body fat - the percentage of your body mass that’s made up of fat. As your fitness increases your percentage lowers.

Question 15

BMI equation?

Answer 15

BMI= body mass (kg) / height squared (m squared)

Question 16

Accuracy & repeatability?

Answer 16

Accuracy- the results should be as close to what’s actually happening as possible.

Repeatability- the procedure should give reliable results. So if the procedure was repeated you’d get the same results.

Question 17

Injuries caused by excessive exercising?

Answer 17

• Sprains- damage to a ligament usually by being stretched too much.
• Dislocation- a bone comes out of its socket.
• Torn ligament- the ligament actually tears. This could mean loss of control of the joint because the bones are not firmly attached.
• Torn tendons- a tear in the tendon that attaches the muscle to its bone. It occurs when a muscle contracts in one direction but is being pulled in the opposite direction.

Question 18

RICE method?

Answer 18

If a sprain is not too severe it can be treated using the RICE method:

Rest- to avoid any further damage. It is important in the first 24 hours. Then the joint can be slowly and progressively used more and more.

Ice- to help to reduce swelling. It works by reducing the temperature and blood flow to the injured area.

Compression- a firm bandage is placed around the injured part to help reduce swelling and prevent damage from excessive movement of the injured joint. You have to make sure it’s not too tight or it will cut off the blood flow to the area.

Elevation- raising an injured limb as high as possible to help reduce swelling by making it easier for blood to flow back to the heart.

Question 19

Physiotherapists?

Answer 19

More serious injuries to the skeletal or muscular system will be treated by a physiotherapist.

A physiotherapist may give treatment to reduce pain and swelling (e.g. RICE) and therapies (e.g. Laser treatment) to speed up healing.

They will also advise on the best exercises to do to rehabilitate after an injury. Theses will be graded exercises which steadily build up the strength of a muscle or joint.

Question 20

Body temperature constant???

Answer 20

• The body has to balance the amount of heat energy gained and lost to keep the core body temperature constant.
• Temperature receptors in the skin detect the external temperature and receptors in the hypothalamus (part of the brain) detect the temperature of the blood.
• The nervous system helps to control body temperature using the following negative feedback mechanism.

Question 21

Negative feedback mechanism?

Answer 21

For example: When your too hot

• Temperature receptors detect that core body temperature is too high.
• The hypothalamus acts as a processing centre- it receives information from the temperature receptors and triggers the effectors automatically.
• Effectors eg sweat glands produce a response and counteracts the change.

(The opposite happens when your too cold)

Question 22

Responses for when your too hot?

Answer 22

• Blood vessels close to the skins surface get bigger in diameter. This is called vasodilation.
• This means more blood gets to the surface of the skin. The warm blood then loses more of its heat to the surroundings.
• Your swear glands produce more sweat. When the water in the sweat evaporates heat is used, which cools the body.
• If you sweat a lot the water loss may cause you to become dehydrated.
• If you’re dehydrated you’ll produce less sweat which means your core body temperature will increase.

Question 23

Responses for when your too cold?

Answer 23

• Blood vessels close to the skins surface get smaller in diameter. This is called vasoconstriction.
• This means that less blood gets to the surface of the skin. Which stops the blood losing as much heat to the surroundings.
• You shiver- your muscles contract rapidly. This increases the rate of respiration and warms the tissue surrounding the muscle.

Question 24

Insulin controls blood sugar levels?

Answer 24

• Eating foods that are high in simple sugars causes your blood sugar level to rise rapidly.
• This is because simple sugars are digested and absorbed into your blood really quickly.
• The level of sugar in your blood needs to kept steady- the body uses insulin to control it.
• When your blood sugar level is too high the pancreas releases insulin which causes sugar to be removed from the blood.

Question 25

Type 1 diabetes?

Answer 25

• It is where the pancreas stop producing insulin.
• This means that the blood sugar level of a person suffering from type 1 diabetes can rise to a dangerous level.
• Its controlled by injecting insulin into the blood usually at mealtimes. The injection has to have the right amount of insulin to make sure the body doesn’t remove too much sugar.

Question 26

Type 2 diabetes?

Answer 26

• Type 2 diabetes is called late onset diabetes as it develops later in life. Having a poor diet or being obese increases the risk of developing this type of diabetes.
• Type 2 diabetes occurs when the body no longer responds to its own insulin or doesn’t make enough insulin. This causes a persons blood sugar level to rise to a dangerous level.
• It can be controlled by exercising and eating a controlled diet.

Question 27

Why are Microorganisms used for industrial use?

Answer 27

• They reproduce rapidly under the right conditions so products are made quickly.
• They have plasmids these can be genetically modified so you can make the microorganism produce the product you need.
• Their biochemistry is simple- fewer reactions happen in microorganisms than in humans. This means you can make the microorganism produce things that they normally wouldn’t without causing them problems.
• They can make complex molecules that are difficult to produce artificially.
• There aren’t any ethical concerns with using microorganisms. As if they were discarded no one would complain.

Question 28

Products made from microorganisms??

Answer 28

• Antibiotics- some types of bacteria and fungi can be used to produce medicines on a large scale.
• Food from fungi- a type of single celled protein made by fungi is used to make meat substitutes for vegetarian meals.
• Enzymes for making foods- enzymes are needed to make some types of food eg. Cheese.
• Enzymes for washing powder- enzymes produced by bacteria can be used to make biological washing powders because they help to break down stains.

• Biofuels- eg Microorganisms can be used to produce biogas a fuel that’s used for things like heating,cooking and lighting.
It’s made by the fermentation of plant and animal waste containing carbohydrates.

Question 29

Genetic modification?

Answer 29

Genetic modification is where a gene from one organism is transferred to another.

The organism with the transferred gene will then produce a protein using instructions in that gene.

The protein can be made even though the gene came from another organism because all organisms have the same genetic code.

Question 30

Stages of genetic modification??

Answer 30

• The gene that’s responsible for producing the desirable protein is isolated. It’s position on the source DNA is identified.
• The useful gene is then replicated to create lots of copies.
• Each gene is joined to a vector- a carrier for the gene which makes it easier to insert into a new cell. Plasmids and viruses are often used as vectors.
• Vectors containing the useful gene are transferred into new cells. Eg bacterial cells.
• Not all of the new cells will be modified. Eg the vector might not have been transferred properly.
• The last stage is to select (identify) the individuals that have been successfully modified.

Question 31

Why is genetic modification useful to humans?

Answer 31

Genetically modified bacteria have been used to make medicine cheaply,quickly and in large quantities. For example;

• Insulin is a hormone that’s used to treat type 1 diabetes.
• The gene for human insulin production can be transferred into bacteria.
• The bacteria are grown in a fermenter and the human insulin is extracted as its produced.
• This means insulin made by the bacteria is exactly the same as human insulin so there is less chance of patients having a allergic reaction to it.

Making crops herbicide resistant;

• Some plants have natural resistance to things like herbicide. (Weed killers)
• Genetic modification can cut out the gene responsible and put it into any useful plant we like.
• Herbicide resistant crops are useful to farmers because they can use a really effective weed killer without damaging their produce.
• However, herbicide resistant crops can be more expensive than normal crops.
• Some people are worried that the gene might be transferred into wild plants making them hard to kill.
• Herbicide resistant crops could encourage the use of weed killers. This could reduce biodiversity and weed killers could pollute water systems or get into food chains.

Question 32

How to test for genetic disorder caused by faulty gene?

Answer 32

• Take DNA sample- DNA isolated from white blood cells is often used to test for genetic disorders. It’s quick and easy to take a blood sample which contains white blood cells.
• Make a gene probe- to identify a faulty gene you can produce a gene probe. This is a strand of bases that’s complementary to the faulty gene that your looking for.
• Use the gene probe- the gene probe is mixed with the DNA. If the gene is present the probe will stick to it- their bases will lock together perfectly.
• A gene probe can find specific sequence of bases.

Question 33

Nanotechnology?

Answer 33

• Food can be made to last longer by adding clay nanoparticles to plastic makes the packaging better at keeping out oxygen and moisture. Some nanoparticles kill harmful microorganism.
• Some “smart packaging” uses nanoparticles to change the packagings properties depending on the conditions.

Question 34

Stem cell technology??

Answer 34

• Tissues and organs grown from stem cells can be used to treat illnesses.

For example;

• Leukaemia can be treated using stem cell technology. Bone marrow transplants can be used to replace faulty bone marrow in patients.
• In the future, stem cells could be used to treat spinal cord injuries by replacing damaged nerve tissue.

Question 35

Biomedical engineering?

Answer 35

• Biomedical engineering uses engineering technologies to improve human health- this includes creating replacement body parts.
• Faulty heart valves can be replaced, either with animal or mechanical valves.
• If the heart cells stop working the heartbeat becomes irregular which is dangerous. The cells can be replaced with an artificial device called a pacemaker.

It’s implanted under the skin and it produces an electric current to control the heartbeat.

Question 36

Outputs are recycled?

Answer 36

• In a perfect closed loop system all the outputs from processes or stores within the system are recycled - they’re used as inputs to other processes in the system.
• There are no outputs from a perfect closed loop system and there are no inputs to it.
• However, most systems aren’t perfect closed loops - they have inputs to them and outputs from them too.

Question 37

Ecosystem closed loop system?

Answer 37

• Ecosystems are closed loop systems because most of the waste (output) produced by organisms isn’t lost. It is recycled as food or reactants for other organisms in the system.

For example;

• Oxygen is a waste product produced by plants during photosynthesis. It is used by plants,animals and microorganisms as a reactant during respiration.
• Carbon dioxide is a waste product produced during respiration. It’s used by plants as a reactant during photosynthesis.
• Dead organic matter (petals,leaves,fruits etc) is used by microorganisms as food.
• Mineral nutrients (nitrogen) are produced by microorganisms when their digestive enzymes break down organic matter. These nutrients are absorbed and used by plants.
• Many organisms like fish and plants produce large quantities of reproductive structures (egg,sperm,pollen etc)

They have to do this because most of the structures won’t grow into adult organisms.

The ones that don’t become adult organisms are recycled in the ecosystems.

Question 38

Stable ecosystems?

Answer 38

In a stable ecosystems e.g. Rainforest, these outputs are balanced by gains.

Large amounts of vegetation grow in stable ecosystems like rainforests.

Question 39

How is vegetation beneficial to ecosystems?

Answer 39

• It reduces soil erosion (where soil is lost from an ecosystem e.g. Blown or washed away.
• It prevents extremes of temperatures.
• It promotes cloud formation.

Question 40

Humans damaging ecosystem?

Answer 40

• Human activities can unbalance natural ecosystems by changing inputs and outputs.

For example, farmers use fertilisers to give plants extra nutrients e.g. nitrates to help them grow. But this unbalances ecosystems because the input of nutrients is much high than normal. It can lead to eutrophication.

• Humans take biomass out of ecosystems for their own use this can damage an ecosystem. For example, over fishing removes a food source for some of the organisms in a food chain.
And unsustainable timber harvesting removes habitats and food sources for some organisms.

• Humans clear natural areas of vegetation in ecosystems so they can grow agricultural crops and raise livestock. For example, they can reduce the biodiversity of an ecosystem. And it can increase soil erosion this can cause soil in the rivers. Making it more likely to flood. It can cause desertification where land becomes infertile and can’t support vegetation.
• Human activities creates non recyclable waste that can’t be used again within a system. This waste can build up to harmful levels in an ecosystem.

Question 41

What’s eutrophication?

Answer 41

Nitrates from fertilised fields can be washed into rivers and lakes by rain.

The nitrates cause lots of algae to grow at the surface of the water which prevents light from reaching the plants and algae below.

These organisms die because they can’t photosynthesis. Bacteria decompose the dead material and use up oxygen.

This oxygen can’t be replaced because photosynthesis is only taking place at the surface. Animals that need oxygen from the water lower down will suffocate.

Question 42

Human systems aren’t closed loop system?

Answer 42

• Human systems for example those found in households, agriculture and industry aren’t closed loop systems.
• Human systems create non recyclable waste.
• Many human systems use fossil fuels like crude oil as an energy source.
• Using fossil fuels produce waste emissions (gases) that aren’t used again in the system.
• When fossil fuels are used it inputs energy into the system from outside the system. The energy in fossil fuels comes from the sun.
• Fossil fuels take millions of years to form from the decay of dead organisms but only seconds to use.
• Because they take so long to form, they can’t be made again within the system.

Question 43

Humans rely on ecosystem?

Answer 43

• Ecosystems provides us with clean air, water and food e.g. Fish and game.
• Ecosystems also provide humans with fertile soil that’s full of mineral nutrients- this is needed for producing crops.
• Crop production also need pollination. Pollination is an “ecosystem service” that’s carried out by organisms (e.g bees) and the wind.

Question 44

Humans and sustainability?

Answer 44

• Sustainability means meeting the needs of today’s population without harming the environment so that future generations can still meet their own needs.
• One part of this is using natural resources at a rate at which they can be replaced naturally. For example;
• Fishing quotas have been introduced to prevent some types of fish such as cod from becoming extinct in certain areas through over fishing. This means they will still be around in years to come.
• To make the production of wood and paper sustainable there are laws in some places insisting that logging companies plant new trees to replace those that they’ve cut down.

Question 45

Sunlight sustainable?

Answer 45

• The Suns energy is sustainable because it can’t be used up by human activities.
• The amount of sunlight that reached Earth in the future will not be affected by how much sunlight we use in the present.
• Sunlight is used as a sustainable energy source in natural ecosystems to make food by photosynthesis.

The sunlight energy is initially stored in the form of carbohydrates and the energy is transferred between organisms when they’re eaten.

• Sustainable agriculture aims to meet the food needs of today’s population without preventing future generations from meeting their own needs.
• Sunlight could be used to power equipment used in sustainable agriculture.

Question 46

Conserving natural ecosystems?

Answer 46

• Communities have to decide between causing damage to an ecosystem to get resources they need and protecting an ecosystem but getting fewer resources.
• A growing population means more people need to be fed.
• People have to decide if it’s worth increasing food production (fishing more could damage ecosystem)

And removing organisms faster than they an be replaced or by increasing desertification.

Question 47

What is blood made of?

Answer 47

• Red blood cells
• Plasma
• White blood cells
• Platelets