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71 Cards in this Set
- Front
- Back
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What is a balanced diet? |
Diet that contains the proper proportions of the food groups to maintain health. |
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What are the different food groups? |
Carbs - Release energy Fats - Keep warm + release energy Protein - Growth, cell repair + replacement Fibre - Digestive system Vitamins + minerals - Keep healthy |
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What is metabolic rate? What affects metabolic rate? Why does activity level effect energy needed? |
The rate at which chemical processes occur Muscle:fat proportion Size (height + weight) Sex Amount of exercise Small amount of genetics Metabolic rate increases during exercise and stays high afterwards. |
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What is obesity? Causes + health problem |
Cause by excess carbohydrates/fat (20%+ over recommended body mass) Bad diet, overeating, lack of exercise, hormonal problems Arthritis, type 2 diabetes, high blood pressure, heart disease, cancer |
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What does too much saturated fat lead to? too much salt lead to? |
High blood cholesterol level High blood pressure |
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What does too little food lead to? Causes + health problem |
Slow growth, fatigue, poor resistance to infection, irregular periods Deficiency diseases (lack of minerals), scurvy - lack of vitamin C |
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What does not enough exercise lead to? |
Exercise makes you healthy, increases energy, decreases fat stored, builds muscle. Doesn't make you healthy. |
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What can inherited factors do? |
Affect metabolic rate (ie. underactive thyroid gland) Some inherited factors increase blood cholesterol level. |
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How do you compare foods? How do you see if a slimming product is reliable? |
More Kj can lead to obesity More salt leads to higher blood pressure More saturated fat raises cholesterol level Look to see if it's from a reputable source, by a qualified person, tested on a large sample, other studies find similar results. |
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What are pathogens? What is bacteria? What are viruses? |
Microorganisms that enter the body + cause disease Small cells which reproduce, damage cells and produce toxins Not cells, use the cells to replicate themselves, damage causes illness. |
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What is the bodies defense system? |
Skin, hair, and mucus in respiratory system stop pathogens. Platelets help blood clot quickly to seal wounds (stop getting into cuts) Anything in immune system, white blood cells |
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What are the different white blood cells? |
Consume - engulf cells and digest Antibodies - molecules have anitgens on the surface + blood cells produce antibodies specifically to kill invading cells, quickly produced and carried around the body Antitoxins - Counteract toxins produced by bacteria |
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What are vaccinations? Pros + Cons |
Injecting dead/inactive microorganisms so the body will produce antibodies to attack them. If live organisms appear again the body can fight. (Sometimes need booster injections) Help control infectious diseases like smallpox, epidemics are unlikely. Don't always work, sometimes cause bad reactions |
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What are drugs? |
There are painkillers but only reduce the symptoms (cold remedies). Antibiotics kill the bacteria without killing body cells, can't treat viruses that way since the body cells would be destroyed. |
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Why is it dangerous to use antibiotics with bacteria? |
They can mutate and become antibiotic resistant, they will then reproduce. Could cause and infection. To slow this down avoid over prescribing antibiotics. |
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How do you investigate antibiotics? |
Microorganisms are grown in a 'culture medium' (Agar - has carbs, proteins, minerals, + vitamins) Hot jelly poured into a petri dish Cooled innoculating loops transfer microorganisms. Paper discs (with antibiotics) placed on jelly Resistant bacteria continue to grow Everything sterilised to stop unwanted bacteria growth. Lid taped down to stop air microorganisms. Schools kept at 25 degrees stop harmful pathogens, can be higher in the industry. |
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What did semmelweiss do? |
Women were dying from puerperal fever. Told doctors to wash hands in an antiseptic solution. Deaths dropped from 12% to 2%, he didn't know why it worked. |
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Why is it problems that diseases have mutated? |
They have become resistant to antibiotics so people can't get rid of them. Bacteria - New strain could be antibiotic resistant/one we've never seen, could spread causing an epidemic. Viruses - Mutate often, DNA changes cause different antigens, hard to develop vaccine. If a deadly virus developed precautions would be taken to stop spread + drugs would be developed |
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What are the sense organs? |
They contain receptors which change stimulus energy into electrical impulses. Eyes, light receptors (Have nucleus, cytoplasm + cell membrane) Ears, sound receptors (+ balance receptors) Nose, smell receptors (chemical stimuli) Tongue, taste receptors (chemical stimuli) Skin, touch, pressure, pain + temperature change |
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What is the CNS? What are the different parts of the CNS? |
Where all info is sent, where everything is coordinated, consists of brain + spinal cord. Neurones transmit electrical impulses to and from the CNS. Instructions are sent to the effectors. Sensory neurone - Nerve cells, carry impulses from receptors to CNS Relay neurone - Nerve cells, impulses from sensory neurone to motor neurone Motor neurone - Nerve cells, impulses from CNS to effector muscles/glands Effectors - Muscles + glands, muscles contracts, glands secrete hormones. |
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What is a synapse? What is a reflex? |
Connection between 2 neurone, transferred by chemicals (sets off a new signal in the next neurone) Reflex - Automatic response, reduces chance of injury |
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What is the reflec arc? |
Passage of information in a reflex. Stimulus detected by receptors, impulse from sensory neurone to CNS. When it reaches a synaps chemicals are released, causing impulses to go along the relay neurone. Same thing happens to a motor neurone, then to effector. Effector then responds. |
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What are hormones? Where are they produced? |
Chemical messengers which travel in the blood to activate target cells. Hormones are for things that need constant adjustment + have long lasting effects. FSH + LH in pituitary gland. Oestrogen in Ovaries |
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What are the differences between nerves and hormones? When would you use nerves over hormones? |
Nerves: fast action, short time, precise area. Hormones: slower, long time, general area. Nerves are used when you need it to react quickly. |
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What is the menstrual cycle? |
Stage 1: Uterus lining breaks down - 4 days Stage 2: Lining builds up - 10 days Stage 3: Egg is released from ovary - Day 14 Stage 4: Wall is maintained - 14 days |
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Where are different hormones in the menstrual cycle made and what do they do? |
FSH - Pituitary, cause eggs to mature, stimulates oestrogen production. Oestrogen - Ovaries, stimulates LH production, inhibits release of FSH LH - Pituitary gland, stimulates release of egg |
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How do you stop fertility? |
Oestrogen - If it's permanently high it stops FSH and stops egg development. Progesterone - Stimulates production of thick cervical mucus, stops sperm The pill: Pro, 99%+ effective, reduces cancer risk Con - Not 100%, causes side effects (nausea, headaches), no STD protection |
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How do you help eggs mature? |
Inject FSH and LH to stimulate egg release Pro - Enable pregnancy Con - Doesn't always work, expensive, too many eggs could be stimulated |
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How does IVF work? |
Collecting eggs from ovaries, fertilising, grown into embryos and transferred into the womb, FSH and LH are injected before egg collection to stimulate egg production. Pro - Enable pregnancy Con - Side effects, increased cancer risk, multiple births can occur |
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What is the plant hormone? |
Auxin - controls growth near tips of shoots + roots. Made in tips + roots to stimulate cell elongations process which occurs behind the tips. Removing tips may stop a shoot growing. |
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What are the different ways auxin controls growth of plants? |
Phototropism - Accumulates on side that's in shade, bends to light. Geotropism - Produce on lower side of shoot (when sideways) bends upwards. On a root it will inhibit growth, so bends downwards. Moisture - Produced on side with more moisture (roots), inhibits growth, grows towards moisture |
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How is auxin used in agriculture? |
Hormones can be extracted/artificial versions made. Hormones can disrupt growth patterns of broad leaved weeds, killing them. Adding rooting powder to soil with plant cuttings in it, they'll produce roots and grow as new plants. |
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What is homeostasis? |
All functions of the body which try to maintain a constant internal environment. |
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What are the different things that homeostasis is used with? |
Ion content - Some are lost as sweat, kidneys will remove the rest. Water - Lost as sweat, breath + urine (Cold day, urine/ hot day, sweat + breath) Body temp - Enzymes need 37 degrees. Brain maintains this. Blood sugar - Insulin maintains so cells have constant energy. (Carbs make glucose) |
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What is a drug? |
Substance which alters what goes on in the body, they can lead to addiction and withdrawal symptoms. |
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What are the different types of drugs? |
Medicinal drugs - Medically useful, may/may not need a prescription. Recreations drugs - Used for fun Performance enhancing drugs - Improve performance in sport. |
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Examples, against and for of performance enhancing drugs? |
Anabolic steroids (Increase muscle size), stimulants (increase heart rate) They have negative health effects (steroids cause high blood pressure) Some are banned by law, are prescription only but all are banned by sporting bodies. For - Unfair, athletes might not be informed of risks. Against - Sport isn't fair anyway, atheletes should have the right to decide the risk |
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What are the drug claims of Statins? |
Lower risk of heart + criculatory disease, evidence they lower blood cholesterol and heart disease in diabetes. Original research was done by gov scientists + 6000 patients. Other studies have backed it up. |
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What are the drug claims about cannabis? |
No one is sure if cannabis causes mental health problems as results have varied so much |
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How do you test medicinal drugs? |
Step 1: Human cells + tissues (not for drugs that affect multiple body systems) Step 2: 2 different live animals, toxicity + best dosage Step 3: Human volunteers in clinical trials, first healthy volunteers (check for side effects), then ill volunteers (most effective dose + few side effects) Patients are blind + split into 2 groups, new drug + placebo. |
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What is thalidomide? |
Intended as sleeping pill but helped with morning sickness, hadn't been tested + affected fetus causing abnormal limb development. Now used for leprosy + cancers |
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What are the links between soft, hard, recreational and illegal drugs?
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Illegal drugs are soft or hard. Hard ones are more addictive and more harmful, soft can still be dangerous though. Cannabis may be a stepping stone or gateway drug to hard drugs - may be down to genetics. |
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What are the damages that legal drugs can cause? |
Smoking - heart disease, blood vessels and lungs, and cancer. Nicotine is addictive. Alcohol - Slows down reactions, impaired judgement, poor coordination, unconsciousness, liver disease + brain damage. (Addictive) More people take them so there is a bigger impact. NHS has to treat diseases caused by them. They cause crime + lost working days. |
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How are animals adapted to heat + cold? |
Heat - Large surface area to volume, small concentrated urine, very little sweat, thin fat layers, thin coat, sandy colour Cold - Small surface area to volume, blubber, thick greasy coat, white fur |
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How are plants adapted to the heat? |
Small surface area to volume (spines not leaves, small surface area in general), water storage tissues, maximize water absorption (shallow but extensive roots, deep roots) |
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How do organisms deter predators? |
Armour - Roses (thorns), cacti (spines), tortoise (shells) Poisons - Bees, poison ivy Warning colours - scare off (wasps) |
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What are extremophiles? |
Microorganisms adapted to living in extreme conditions (volcano vents, salty lakes, high pressure sea bed) |
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What do organisms compete for? |
Plants need light, space, water + minerals from the soil Animals need space, food, water + mates |
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What are environmental changes caused by? |
Occurence of infectious diseases, number of predators/food sources, number/types of competitors, temperature change, rainfall change, air/water pollution change. Population increase (More prey = more predators) or decrease (Bees - pesticides, less food, more disease) Where an organisms lives (distribution changes) |
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What are living indicators? |
Sensitive to changes in the environment and can show the effects of human activities. |
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Examples of living indicators? |
Lichen - Sensitive to SO2 concentration, a lot means air is clean. Mayfly Larvae - Sensitive to oxygen in water, water sewage increases bacteria which uses oxygen, lot = clean water Inverterbrates - Adapted to polluted areas (Rat tailes maggots + Sludgeworms) |
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Eexamples of non living indicators? |
Satellites - Temperature of sea surface, amount of snow + ice cover Automatic weather stations - Atmospheric temperature Rain gauges - find out average rainfall changes Dissolved oxygen meters - Concentration of dissolved oxygen to find levels of water pollution |
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How do pyramids of biomass work? |
There's less energy and biomass as you move up a trophic level in a food chain. Each bar represents the mass of living materials, the bar at the bottom is the producer, then the primary consumer, then the secondary consumer. |
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How does energy transfer and decay occur with pyramids of biomass? |
Green plants and algae use light to make food which is stored in the cells (this energy makes its way through the food chain), respiration supplies energy which will eventually be lost as heat. Some organism material is inedible so it won't pass onto the next stage. Some energy is lost as waste materials (why biomass pyramids are pyramid shaped) |
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What is decay? |
Organisms take in elements which are returned to the environment as waste or when it dies, they decay as microorganisms digest them (work best in warm, moist, oxygenated conditions). Elements are recycled, plants take them from the soil again. In a stable community there is a constant cycle. |
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How do compost bins work? |
Kitchen waste is made into compost and used as fertiliser, warmth is generated by decomposition and mash sides let air in (for ideal conditions) |
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What is the carbon cycle? |
Powered by photosynthesis (removed from atmosphere) Plant + algae, and animals respire, giving it out. Moves into animals when plants are eaten. Demitrus feeders + microorganisms respire (feed on plants, algae + animals) Animal waste - is broken down by df+m, compounds in the waste are taken from the soil by plants. Plant + animal products are burnt - combustion releases it into the air |
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What is variation? What is genetic variation? What is environmental variation? |
Difference which exists between members of the same species Caused by genes from parents, passed on in gametes, combination of genes causes it. Caused by conditions you live in |
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What is DNA? What is an allele? |
Cells have a nucleus which carries chromosomes Chromosomes carry genes which control characteristics DNA forms the arms of the chromosome Alternative versions of genes |
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What is sexual and asexual reproduction? |
S - Fusion of male + female gametes, mixture of genetcis will cause variation A - Only one parent, no fusion, no mixture, no variation, creates clones |
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How do you create clones of plants? |
Cuttings - Take cutting with buds + keep in moist conditions (quick + cheap) Tissue culture - Put cells in growth medium w/ hormones (quick, done in little space, grow all year) |
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How do you create clones of animals? |
Embryo transplant - Fertilise egg, split (make clones), then implant into the animal Adult cell cloning - Remove nucleus from egg, then insert complete set of chromosomes, stimulated by electric shocks (divides), then implanted into adult female. |
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What are the issues with cloning animals? |
Creates a reduced gene pool (bad for disease resistance), may not create as healthy animals, humans could be cloned unsuccessfully. However could help with understanding diseases + preserve endangered species |
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How do you perform genetic engineering? What is it used for? What are the worries? |
Cut gene with enzymes, then cut chromosome and insert a gene. Bacteria produce human insulin GM Crops; resist viruses, insects or herbicides Sheep; drugs in milk for diseases Gene therapy; insert working genes into genetic disorder sufferers Could cause unplanned problems for future generations |
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What are the pros + cons of GM crops? |
Could reduce biodiversity, might cause allergies, could get into natural environment. But can increase crop yield, can engineer plants to contain nutrients, are being grown without problems. |
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What are evolutionary and ecological relationships? |
Evolutionary - Similar genes means there's a recent common ancestor, they usually look alike and live in similar habitats. Evolutionary trees show this. Ecological - Similar characteristic probably means there's competition, different probably means there's a predator prey relationship |
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What is natural selection? |
Charles Darwin said, variation is shown because of genes, better adaptations mean better survival chance, higher breeding chance, then better genes are passed on. |
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What is a mutation? |
Change in DNA, can produce a useful characteristic which will accumulate in a population. |
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Why was Darwin's theory controversial? |
Went against religion, couldn't explain it (variation and genes were not found out for 50 years), not enough evidence/not many other studies done. |
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What was Lamarck's theory? |
If a characteristic was used a lot it would develop more, then would pass on to the next generation. |
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Why can different hypotheses appear from similar observations? |
Because of different beliefs, influence from different people or thinking differently. |
