B7 – Further Biology

Respiration

  • Respiration isn’t breathing in and out.
  • It’s the process of releasing energy from glucose, which happens constantly in every cell.
  • Aerobic respiration needs plenty of oxygen.
  • Glucose + Oxygen → Carbon Dioxide + Water (+ energy released)
  • Energy released from respiration is used to make ATP.
  • It’s broken down to ADP when energy is released.
  • ATP is synthesised from ADP using energy from respiration.
  • You respire more when you exercise.
  • More ATP is used to contract you’re muscles so you need more energy, so respiration increases.
  • Breathing rate increased to get more oxygen into the blood.
  • Heart rate increases to get glucose and oxygenated blood around the body to your muscle quicker, and remove CO₂ quickly at the same time.
  • Anaerobic respiration doesn’t use oxygen at all.
  • Sometimes you can’t supply your body with all the oxygen that it needs.
  • So in anaerobic respiration glucose → lactic acid (+ energy released) and you produce energy but lactic acid builds up in your muscles.
  • You need oxygen to clear up this acid, so you are in an oxygen debt.
  • So you keep breathing for a while after you stop exercise.

Blood and blood typing

  • Blood is a fluid made of cells, platelets and plasma.
  • Red blood cells – Transports oxygen from lungs to all the cells in the body.
  • Plasma – Liquid that carries everything.
  • White blood cells – Fight infection from microorganisms.
  • Platelets – Small cell fragments that help the blood to clot.
  • Blood type is important in transfusions.
  • If you have the wrong blood in you it can trigger the immune system to attack it and it will make the blood clot.
  • Blood type A has A antigens and B anti bodies, so B has B antigens and A antibodies.
  • AB has no antibodies so can take all blood but because of its 2 antigens it can’t give blood.
  • O is opposite to AB as it has no antigens but both antibodies.

Inheritance of Blood types

  • Alleles are different versions of the same gene.
  • ABO blood type is determined by a single gene that has 3 alleles.
  • Io is for blood type O. Ia for A, and Ib for B.
  • Io is recessive but Ia and Ib are co-dominant.

The Circulatory System

  • Humans have a double circulatory system.
  • One pumps deoxygenated blood to the lungs and back to the heart.
  • One pumps oxygenated blood around and back to the heart.
  • Chemicals are being exchanged between cells and capillaries.
  • Arteries branch into capillaries which are tiny blood vessels.
  • Small molecules (water, glucose and oxygen) are forced out of the capillaries into the tissue fluid.
  • Chemicals diffuse from tissue fluid into the cells and waste chemicals leave the cells and diffuse into the capillaries.

The skeletal system

  • Skeletons support and protect you.
  • Joints allow bones to move.
  • Cartilage lets the joints rub.
  • It’s also a shock absorber.
  • Membranes at some joints release synovial fluid to lubricate joints.
  • Muscles pull bones to move them.
  • Bones are attached to muscles by tendons.
  • When the muscle contracts the tendon pulls the bone and you move.

Health and Fitness

  • Patients need regular contact with practitioners.
  • Health - Medication is working and re-evaluates treatment, also check for side effects.
  • Fitness – encouragement, monitor progress and adjust aims and check for injuries.
  • Information is needed to develop the right treatment regimes.
  • Symptoms, previous health or fitness, family medical history and current physical activity.
  • Practitioners need to keep records.
  • Remembering background information of patient, remembering the health or fitness plan, monitoring changes for progress and to share information with of professionals so people have the best information on a person.
  • Treatments can have side effects, but sometimes the benefits outweigh the risk.
  • There is usually more than one way to achieve a target.
  • Enhanced fitness – Different things, maybe faster running or increased flexibility.
  • Cure – Often the best cure is waiting for things to heal naturally.
  • Recovery and rehabilitation – Same level of ability from before the injury, maybe progressively more difficult tasks.
  • The treatment may need to be modified.
  • No improvement.
  • Damage
  • Side effects that outweigh the benefit of treatment.
  • Excessive exercising can cause injuries.
  • Sprains – Damage to ligament.
  • Dislocations – Bone leaves its socket, causing severe pain.
  • Torn ligaments – Lose of control of a joint because they aren’t severely attached to the bone.
  • Torn tendons – When a muscle contracts and is pulled in the other direction.
  • The RICE method can be used to treat sprains.
  • Rest – avoid further damage
  • Ice – Reduce swelling
  • Compression – Reduce swelling and reduce joint movements.
  • Elevation – Stops fluid going to the joint and swelling it up.
  • Physiotherapists treat skeletal-muscular injuries.
  • Treatment.
  • Advice.

Pyramids of numbers and biomass

  • Pyramids of numbers are a way of showing food chains.
  • Producer at bottom, pro killer at top.
  • Misleading because the shape can be changed by the presence of a big organism like a tree.
  • Pyramids of biomass give an accurate picture.
  • They give a fairly accurate indication of the amount of energy at each level of the food chain.
  • They show the mass of living material at each level.

Energy transfer and energy flow

  • Energy is transferred between organisms in an eco-system.
  • Energy from the sun is the source of energy for nearly all life on earth.
  • If an animal eats a plant or another animal it takes the stored energy, and that works its way through the chain.
  • Energy passes out by
  • Respiration
  • Heat
  • Excretion
  • Some material like bones isn’t eaten, so it’s not passed on.
  • Food chains are rarely very long because so much energy gets lost one can’t support many layers.
  • You need to be able to calculate the efficiency of energy transfer.
  • % efficiency = energy available to next level/energy available to previous level x 100

Biomass in soil

  • Soil contains for main things.
  • Inorganic matter – Rock, mineral irons ect.
  • Biomass – Living and dead organic matter. Worms and stuff, and dead worms and other dead stuff.
  • Water – Good for plants
  • Air – Vital for respiration of soil animals and roots.

Symbiosis

  • Living together in direct contact.
  • Commensalism – Benefits one, but the other isn’t harmed.
  • Parasitism – One benefits and one is harmed.
  • Tapeworms:
  • Live on digested food.
  • Large surface area so can get food by diffusion.
  • Suckers to attach it to the wall of the intestines.
  • Blood flukes:
  • Pointed head so they can burrow through the skin.
  • The can incorporate human antigens onto their surfaces making them invisible to the host’s immune systems.
  • Parasites can affect us by...
  • Causing disease
  • Affecting food.
  • Parasite evolution is connected to that of its host.

Parasitism

  • Malaria is a human disease caused by a parasite.
  • African population suffer from sickle cell anaemia.
  • Sick cell anaemia affects red blood cells.
  • Red blood cells can’t carry oxygen well because they are shaped like sickles.
  • It’s caused by a faulty recessive gene.
  • 25% chance of having a child suffering from the disorder if two carriers get together.
  • Carriers have some protection from malaria.
  • Malaria uses the red blood cells to grow in, but they can’t live in the sickle ones, so carriers are less likely to get malaria
  • Gives an increase chance in survival
  • So they are more likely to pass on their genes.

Photosynthesis

  • Plants produce glucose by photosynthesis.
  • Makes food in plants. It’s glucose, a sugar.
  • Carbon dioxide + water → (sunlight, chlorophyll) → Glucose + oxygen
  • It happens inside chloroplasts which absorb sunlight and use its energy to convert^
  • Plants use the glucose in 3 main ways.
  • In respiration to produce energy.
  • To make chemicals for growth.
  • To store as starch, ready to use in times when light is little.

Rate of photosynthesis

  • Three factors
  • Light, CO₂ and temperature.
  • Any of these can be a limiting factor, which slows down the rate.
  • Not enough light or CO₂ slows the rate.
  • As you increase light the rate will increase.
  • Eventually it will level off and something else will become the limiting factor.
  • Temperature.
  • Too low the enzymes work too slowly.
  • Too high and one will denature.
  • You can measure the rate under different conditions.
  • Gas syringe connected to a tube with water and a pondweed, change conditions and check the amount of O₂ produced.
  • Only change one variable at the time.
  • To get it a fair test and reliable.

Plants and respiration

  • Respiration releases the energy in glucose.
  • Compensation points are when the plant is making the same amount of energy that it is using.
  • Energy from respiration is used in active transport.
  • Moving minerals from the soil (low concentration) to the root (higher concentration).

Humans and the atmosphere

  • Human activity produces a lot of carbon dioxide.
  • Cars, electricity production, industrial processes.
  • Trees are being cut down and they use CO₂
  • Increased CO₂ may be causing global warming.
  • Expanding sea, melting ice...
  • More hurricanes due to warmer water.
  • Different weather so drought and stuff.

Biotechnology

  • Bacteria have a simple structure.
  • Very small.
  • No nucleus.
  • Contain plasmids.
  • Microorganisms are grown in fermenters on a large scale.
  • Perfect conditions for them.
  • Microorganisms can help us produce...
  • Food from fungi like quorn.
  • Antibiotics like penicillin.
  • Enzymes for food manufacturing like rennin.

Genetic Modification

  • Gene modification is great.
  • New useful microorganisms.
  • Plants resistant to stuff.
  • Genetic modification involves important stages.
  • Wanted gene is isolated.
  • Cut from DNA using restriction enzymes and isolated.
  • Gene joined to a vector (often the plasmid or a virus).
  • Now inserted into the host DNA of the organism to produce desired characteristic.
  • Genetically modified organisms can be used to make insulin.
  • Cultured in a fermenter.
  • Modified microorganisms are cheap and easy.
  • They might mutate and become dangerous.
  • GM crops
  • Pros
  • Increase yield.
  • More nutrients for poorer countries
  • Cons
  • Might be unsafe or cause allergies.
  • Transplanted genes may get out into the environment and damage the ecosystem.

DNA technology – Genetic testing

  • Genetic testing can help identify genetic disorders.
  • Faulty gene.
  • Chromosome abnormality.
  • Complementary DNA can be used to find a gene.
  • Identifying a faulty gene. A gene complimentary to the gene you are looking for. Use a gene probe.
  • Identifying a chromosome abnormality. How many times the chromosome is present by locating a gene that’s only in that chromosome. If the gene is there more or less than normal then it’s abnormal.
  • A gene probe
  • A gene probe is mixed with the DNA. If the gene you’re looking for is present their bases will lock together.
  • Gene probes are tagged so you can find them.
  • A chemical tag stuck on the end of a sequence. So you can locate the gene probe once it’s stuck to a gene.
  • Florescent – Will glow and show up under UV light.
  • Radioactive chemical – Detected using autoradiography, like an x-ray.
  • If the gene is present, the chromosome will have a highlighted bit on it where the gene is present.