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B1 Human Biology and some on environment. Flashcards

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0
Q

How can metabolic rate change from person to person.

A

The metabolism is the rate of reactions in the body.
People with a higher proportion of muscle in their bod will have a higher metabolism.
Physically bigger people also have a higher metabolism.
Men tend to have a higher metabolism as they are bigger and have a larger proportion of muscle.
Regular exercise boosts the resting metabolic rate as it build up muscle.
Age can also affect it.

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1
Q

Name the different food groups needed and what they are used for.

A

Carbohydrates release energy.
Fat keeps you warm and releases energy.
Protein is used for cell repair, cell growth and cell replacement.
Fibre is used to make sure everything runs smoothly for the body.
Vitamins and minerals keep the skin,bones, blood and everything else healthy.

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2
Q

How do activity levels affect energy intake?

A

When you exercise more energy is needed. The metabolic rate goes up and stays up for some time afterwards.
People with more active jobs need more energy on a daily basis.
This means if you aren’t very active, you should take in less energy.

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3
Q

What does malnourished mean?

A

It means a person is deficient in a certain food group. The malnourished can be fat or thin.

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4
Q

How does eating too much lead to obesity?

A

An excess of carbohydrates or fat in the diet leads to obesity.
Hormonal problems can lead to obesity but the usually causes are a bad diet, overheating and a lack of exercise.

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5
Q

When is a person defined as being obese?

A

When the mass is 20% over the recommended body mass.

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6
Q

What health problems can arise because of obesity?

A

Arthritis, type 2 diabetes, high blood sugar levels, heart disease. And some types of cancer.

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7
Q

What other problems arise from eating too much of something?

A

Too much saturated fat in the diet means that blood cholesterol levels go up.
Too much salt causes a high blood pressure and heart problems.

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8
Q

What health problems arise from eating too little?

A 
Slow growth (in children) fatigue, poor resistance to infection, and irregular periods in women.
Deficiency diseases come about through a lack of vitamins or minerals. A lack of vitamin C can cause scurvy which produces problems with the skin, joints and gums.
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9
Q

How can a lack of exercise cause health problems?

A

Exercise increases the amount of energy used by the body and decreases the amount stored as fat. It also builds muscle so it boots the metabolic rate. Those who exercise are less likely to suffer from obesity.
It is however possible to be fit but not healthy. You can be physically fit and slim but malnourished.

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10
Q

How do inherited factors affect health?

A

Some people may inherit factors that affect the metabolic rate. Some inherited factors cause an under active thyroid gland, lowering the metabolic rate and causing obesity.
Other people may inherit factors that affect blood cholesterol.
Cholesterol is a fatty substance needed for good health but too much can increase the chance of heart disease.

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11
Q

What things do you have to look out for when evaluating a method of losing weight?

A

Have there been other studies which found similar results?
Was the sample of people tested large enough?
Was it written by a qualified person? Would they have been biased?
Is the report a scientific study, published in a reputable journal.

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12
Q

What are the two main types of pathogen?

A

Bacteria and viruses.

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13
Q

Describe bacteria.

A

They are very small cells. 0.001th of the size of your body cells.
They induce illness by damaging cells and producing toxins.

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14
Q

Describe viruses.

A

They aren’t cells. About 100 times smaller than bacteria.
They replicate them selves by invading the cells and hijacking it so it produces more copies of themselves. The cell will usually then burst.
This cell damage causes illness.

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15
Q

How does the body try and stop pathogens from getting into the body?

A

Skin and hairs and mucus in the respiratory tract stop them.
To prevent pathogens getting in through cuts, platelets help to make blood clot quicker to seal the wound.
If something does get in, the immune system has to do something.

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16
Q

How do white blood cells fight pathogens?

A

They engulf and ingest them.
They produce anti toxins that counteract the toxins produced by the bacteria.
They will detect the antigens on invading pathogens. They will produce antibodies that lock on and kill the invading cells.
They only work on certain types of pathogens.
They are produced rapidly and if a person gets infected with the same pathogen again ,the antibodies will be produced quicker.
Immunity would have been created.

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17
Q

How do vaccinations work?

A

When you are affected with a microorganism, the body takes a while to learn how to deal with it.
Vaccinations involve injecting small amounts of dead or inactive microorganisms, which have the same antigens. The right antibodies will have been created to defend against it.
If a live microorganism enters the body, the antibodies will have been produced a lot quicker.
Some wear off over time, meaning booster injections will have to be given.

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18
Q

What does the MMR vaccine protect against?

A

Measles, mumps and rubella.

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19
Q

What are the advantages of vaccines?

A

They controls the spread of infectious diseases. Smallpox has been destroyed and cases of polio have fallen by 99%.
Epidemics can be prevented if a large proportion of the population has a vaccination. Those who haven’t been vaccinated will still be safe as there are less people who can give it to them.

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20
Q

What are the disadvantages of vaccines?

A

They don’t always provide immunity.

Some time there will be a bad reaction. Swellings, fevers or seizures. These are very rare.

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21
Q

What do painkillers do?

A

They relieve pain. They stop the symptoms but don’t stop the disease. They body has to do that.

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22
Q

What do antibiotics do?

A

They kill or prevent the growth of bacteria causing the problem, without killing body cells. Different antibiotics kill different types of bacteria so the right one has to be given.
However, they don’t destroy viruses so they won’t work against the flu or cold.

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23
Q

Why is it very hard to produce medicine that can cure viruses?

A

They reproduce within the body cells so killing them will mean killings the cells as well.

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24
How can bacteria become resistant to antibiotics?
They can mutate and these can cause resistance to antibiotics. If you have an infection, some of them will be resistant and they won't die. They can survive and reproduce. The population of the resistant bacteria will go up. As they can't be treated with antibiotics which means they can cause serious infection. Like MRSA
25
How is the spread of antibiotic resistant bacteria stopped?
Doctors must avoid over prescribing antibiotics. They won't be given for a sore throat.
26
How would an investigation into the effectiveness of antibiotics take place?
Hot agar jelly would be poured into a petri dish where bacteria could grow. An inoculating loop would be passed through a flame and this would be used to transfer the bacteria. Paper discs soaked in different types of antibiotics would be placed in the Petri dish. Looks at the amount of bacteria growth around each of the bits of paper. The Petri dish must have a lid to stop unwanted microorganisms from the air getting in. In school the cultures would be kept at 25C to stop harmful pathogens from growing.
27
What did Ignaz Semmelweis do and discover?
He saw that many women were dying in child birth because of puerperal fever. The believed doctor were spreading the disease on unwashed hands. He had doctors wash their hands with antiseptic locutions and the death rate fell by 10% However microorganisms hadn't been discovered so he couldn't prove his methods. They are dropped when he left the hospital. Now the importance of basic hygiene is understood.
28
What is a possible problem with bacteria?
They can mutate to produce new strains and these could be antibiotic resistant. Or a new strain could be one no-one has encountered so no one is immune. It could spread rapidly in a population and cause a epidemic.
29
What is a possible problem with viruses?
They mutate often meaning it is hard to produce vaccines against them as the antigens are always changing. A virus could evolve to so it was infectious and deadly. If this happened the spread of it would have to be stopped spreading. Vaccines and antiviral drugs would have to be developed but this would take time. In the worst case scenario, a pandemic could kill billions.
30
Define stimulus.
A change in the environment which you may need to react to. | They could be light, sound touch, pressure, pain, chemical or a change in position or temperature.
31
What are the sense organs and what receptors do they contain?
Eyes. Light receptors. Ears. Sound and balance receptors. Sensitive to light and changes in position. Nose. Smell receptors sensitive to chemical stimuli. Tongue. Taste receptors. Skin. Sensitive to touch, pressure, pain and temperature change.
32
What are effectors?
Muscles or glands that respond to motor neurones. | They contract or secrete hormones.
33
What are motor neurones?
Nerve cells that carry signals from the central newborns system to the effector.
34
What are relay neurones?
Nerve cells that carry signals from sensory neurones to motor neurons.
35
What are sensory neurons?
Nerve cells that carry signals as electrical impulses from the receptors in the sense organs to the central nervous system.
36
What is the central nervous system?
Information from sense organs is sent here and reflexes and actions are coordinated here. It consists of the brain and the spinal cord.
37
What is a synapse?
A connection between two neurones. A nerve signal is transferred by neurotransmitters which diffuse across the gap. The neurotransmitters set off a new electronic signal in the next neurone.
38
What are reflexes and how do they prevent injury?
They are automatic responses to certain stimuli. | If a bright light is shined into the eye, the pupils automatically get smaller so less light can get in.
39
Describe the reflex arc.
A stimulus is detected by receptors and implies are sent along the sensory neurone to the CNS. This then goes to a relay neurone, then a motor neurone, than a effector and then there is a response. As it doesn't go to the brain and just goes to the CNS, it is very quick.
40
What are hormones?
They are chemicals that are released directly into the blood. They are carried by blood plasma to other parts of the body but only affects the target cells. They controls things that need constant adjustment and are produced by many different glands like the pituitary.
41
How are nerve signals and hormones different?
Neves are faster, act for a shorter amount of time and act on a very precise area, where hormones act in a more general way.
42
Explain stage 1 of the menstrual cycle.
Lasts for 4 days. The bleeding starts as the uterus lining breaks down.
43
Explain stage 2 of the menstrual cycle.
The lining of the uterus starts to build up from days 4 to 14. There will be a thick spongy layer of blood vessels ready to receive a fertilised egg.
44
Explain stage 3 of the menstrual cycle.
An egg is released from the ovary at day 14.
45
Explain stage 4 of the menstrual cycle.
The wall is maintained for about 14 days until day 28. If no fertilised egg has landed the layer will start to breakdown again and the cycle will start again.
46
What are the three main hormones used in the menstrual cycle?
FSH, Oestrogen and LH.
47
What does FSH do?
Follicle stimulating hormone. Produced in the pituitary gland. Causes an egg or mature in one of the ovaries. Stimulates the ovaries to produce oestrogen.
48
What does oestrogen do?
Produced in the ovaries. Causes the pituitary to make LH. Inhibits the further production of FSH.
49
What does LH do?
Luteinising hormone. Produced by the pituitary gland. Stimulates the release of an egg in the middle of the menstrual cycle.
50
What does progesterone do?
It is produced in the ovaries. It stimulates the production of thick cervical mucus.
51
How can oestrogen be used as a contraceptive?
It prevents the release of an egg. A pill containing it is taken and it keeps levels high. This stops FSH from being made meaning egg development and production will stop.
52
What are the positives of using the pill?
It is 99% effective at stopping pregnancy. | It reduces the risk of getting certain types of caner.
53
What are the cons of using the pill?
It isn't 100% effective. It can cause side effects like headaches, nausea, irregular menstrual bleeding and fluid retention. It doesn't protect against STI.
54
How can hormones be used to encourage pregnancy?
If the levels of FSH are too low to cause eggs to mature the woman can't get pregnant. FSH and LH can be injected to stimulate the release in the ovaries.
55
What are the pros of using hormones to encourage pregnancy?
It help them to get pregnant.
56
What are the cons of using hormones to encourage pregnancy?
It doesn't always work and it is expensive. | Too many eggs could be simulated meaning that they would be unexpected multiple pregnancies.
57
How does IVF work?
It involves collecting eggs from the ovaries and fertilising them in a lab using sperm. Embryos are grown and then put into the uterus. FSH and LH are given before egg collection to stimulate egg production.
58
What are the pros of IVF?
An infertile couple can have a child.
59
What are the cons of IVF?
Some women will have a strong reaction to the hormones like abdominal pain, vomiting, dehydration. Some reports say there is an increased risk of cancer by using the hormones. Multiple births can occur which is more risky for the child and mother.
60
What is auxin?
It is a plant growth hormone, found in the tips of roots and shoots. It controls the direction of growth in response or light(phototropism) gravity (geotropism) or moisture(hydrotropism) It is produced in the tip and moves backwards to stimulate cell elongation which occurs in cells behind the tip. If the tip is removed, the shoot may stop growing. Extra auxin promotes growth in shoots but inhibits it in roots.
61
How do shoots grow towards light?
When a tip is exposed to light, more auxin accumulates on the side that is in the shade. This makes the cells grow faster on the shaded side so the root bends towards light.
62
How do shoots grow away from gravity?
When a shoot is growing sideways, gravity produces an unequal distribution of auxin in the tip with more on the lower side. This causes the lower side to grow faster bending the shoot upwards.
63
How do roots grow to gravity?
A root will have more auxin on the lower side. | This will inhibit extra growth, so the top will grow faster and go towards gravity.
64
How do roots grow towards moisture?
A uneven amour of moisture on either side of the root will produce more auxin on the side will more moisture. The inhibits growth on that side causing the root or bend in that direction, towards the moisture.
65
How can plant hormones be used in agriculture?
Most weeds are broad leaved while grasses and cereals have narrow leafs. Selective weed killers can be made our of plant growth hormones. They only affect the broad leaved plants by disrupting their normal growth pattern, killing them. Plant cuttings won't always grow in soil. If rooting powder is added(it contains auxin) more roots will be produced and it will start to grow as a new plant. This means lots of clones can be made really quickly.
66
What four things does the body need to keep constant?
Ion, sugar and water content. Temperature.
67
How is ion content regulated?
Ions enter the body through food and are absorbed by blood. If there are too many of any type of ions they will have to be removed. Some ions are lost in sweat. The kidney will also remove excess from the blood. This is removed in urine.
68
How is water lost from the body?
Through the skin as sweat. Via the lungs in breath. Via the kidneys as urine.
69
What are drugs?
Chemicals that interfere with chemical reactions in the body.
70
Name some very addictive drugs.
Heroin, cocaine, nicotine and caffeine.
71
Explain the different types of drugs.
Medical drugs can be like antibiotics. They help the body. For some you don't need a prescription(paracetamol) but for others you do as they can be dangerous if miss used.(morphine) Recreational drugs are used for fun. Performance enhancing drugs can improve performance in sport.
72
Explain performance enhancing drugs.
Anabolic steroids increase muscle size and stimulants increase heart rate. They can have negative effects. Like high blood pressure. Some of these drugs are banned by law, some are prescription only but sporting oldies ban all.
73
What are the arguments for performance enhancing drugs?
It is the choice of the athlete to use the drugs. | Sport isn't fare anyway. Athletes have different coaches, equipment and training facilites.
74
What are the arguments against performance enhancing drugs?
The athletes may not know about the health risks. | It's unfair as people gain an advantage which isn't through training.
75
What is the first stage of drug testing?
They are tested on animal and human tissue in labs. However, single cells and tissues can't be used when testing drugs that affect whole multiple body systems. Many fail here as they damage cells or don't work.
76
What is the second stage of drug testing?
It is tested on live animals. This is to see if it works, the toxicity and the best dosage. The law in Britain says drugs must be tested on two different types of live animals. Some say this is cruel.
77
What is the third stage of drug testing?
It is tested on humans in clinical trials. At first it is tested on healthy people so see if there are any side affects. A very low dose is given at the start and this is gradually increased. If these results are good, it is tested on ill people. The optimal dose is found. Patients are put into two groups. One is given the drug while the other is given a placebo. This means they can see if the drug works better than the placebo effect. They are often double blind, meaning the patients and the doctor don't know who has had what. This prevents subconscious influences.
78
Give an example of what happens when drugs aren't thoroughly tested.
Thalidomide was developed in the 50s and was meant to be a sleeping pill. However, it was also found to relieve morning sickness in pregnant women. However it wasn't tested for this use so they didn't know it could affect the fetus and cause abnormal limb development. 10,000 baby's were affected and only hard survived. The drug was banned and more rigorous testing was put in place. Recently, it was used in the treatment of leprousy and other diseases.
79
What are soft and hard drugs?
Illegal drugs that are more addictive and harmful or less. | These are however vague terms. Heroin, ecstasy and cannabinol can all cause heart and circulatory system problems.
80
Why do people use recreational drugs?
Takers of cannabis say it causes relaxation or stress relief. It can produce inspiration. Factors on background and personal life can also influence them. Some multiple sclerosis sufferers say cannabis can help to relieve pain.
81
How can cannabis be linked to harder drug use?
It is a stepping stone drug. Using it means you want to try harder drugs. It is a gateway drug. It puts people into contact with dealers. It is because of genetics. Those who take cannabis are naturally more likely to try harder drugs.
82
What are the impacts of smoking?
It can cause diseases of the heart, blood vessels and the lungs. The smoke can cause cancer. Nicotine is addictive meaning it is hard to stop smoking.
83
What are the effects of alcohol?
It has an effect on the nervous system, slowing down reactions. It causes impaired judgement, poor coordination and unconsciousness. Excessive drinking causes damage to the brain and liver. It is addictive.
84
How does tobacco and alcohol affect society?
As many people take them, their effects are lager than those of illegal drugs. The NHS has to spend money on treating those with problems that the two cause. Alcohol causes criminal damage and violence which means more has to be spent on the police. They both harm the economy as they cause people to miss days off work. They also cause sorrow and anguish to those affected.
85
How are desert animals adapted?
Camouflage. A sandy colour means they can avoid predators or sneak up on prey. Efficient with water. They produce small amounts of concentrate urine. They also sweat less. Camels can tolerate big changes in temperature and kangaroo rats live in cool burrows. Thin layers of body fat and a thin coat lets heat escape. Camels have all their fat in their humps. Large surface area compared to volume. This lets desert animals lose heat.
86
How have arctic animals adapted?
Small surface area compared to volume. This means less heat is lost. Well insulated. They have a thick layer of blubber for insulation. This also acts as a fuel store. Camouflage. Arctic animals have white fur to avoid predators and sneak up on pray.
87
How have desert plants adapted?
Small surface area compared to volume. This limits water loss from the surface of the leafs. Cacti have spines. Water storage tissues. For example a cactus stores water in its thick stem. Maximising water absorption. Some have shallow but extensive roots to absorb water quickly over a large area. Others have deep roots to access underground water.
88
How are some plants and animals, adapted to deter predaotors?
Some plants and animals have armour like thorns, cacti or tortoises. Others produce poisons. Like bees and poison ivy. Some have warning colours to scare off predators. Like wasps.
89
How are microorganisms adapted?
Some are known as extremophiles. They can live in seriously extreme conditions like volcanic vents, salty lakes or at high pressure. They can survive high temperatures, a high concentration, high pressures.
90
What do plants compete for?
Light, space, water and minerals from the soil.
91
What do animals compete for?
Space(territory) food, water and mates.
92
Name some living changes in environment.
A change in the number of infectious diseases. A change in the number of predators. A change in the number of prey or availability of food. A change in the number of competitors.
93
Name some non-living changes in environment.
A change in average temperature. A change in average rainfall. A change in the level of air or water pollution.
94
What are the three ways in which environmental changes can affect populations?
An increase. This can happen is there's more food available. A decrease. They could be more disease or less food. A change in the distribution. A change in where organisms live. For example in Germany, the rises in temperature means birds are living in different places.
95
How can air pollution be measured by looking at lichen?
Certain types of lichen are sensitive to sulphur dioxide in the air. This provides an indication into the level of pollution caused by car exhausts or power stations. The number and type of lichen are measured.
96
How are living indicators used to measure pollution in rivers?
If raw sewage gets in a river, the bacterial population will have gone up and used all the oxygen. Mayfly larvae are very sensitive to the concentration of dissolved oxygen. If the larvae can be found, the water is clean. Also some species can survive in polluted conditions. Lots of rat-tailed maggots or sludge worms means lots of pollution in the water.
97
What are the non living indicators of environmental change?
Satellites can be used to measure the temperature of the sea surface and the amount of snow and ice cover. Automatic weather stations tell us atmospherics temperature at various locations. They also measure rainfall to find average rainfall year on year. They have dissolved oxygen meters to discover the levels of water pollution.
98
What is a tropic level?
A stage on a food chain.
99
What's do the bars on pyramids of biomass represent?
The bottom: producer Second bottom: primary consumer. Third bottom. Secondary consumer. And so on.
100
Why is so much energy lossy with each tropic level in a food chain?
Green plants and algae use a small amount of the suns energy and this is stored in the plant. Respiration supplies energy for all life processes including movement. Most of this energy will be lost as heat. This is very true for mammals and birds who have to maintain a constant body temperature. Some animal matter is indelible like bone. This energy can't be passed on. Energy is also lost as waste material.
101
Why are food chains, never have more than five tropic levels?
They isn't enough energy to support any more organisms.
102
How are materials taken from the soil, put back?
Plants will take simple things like, carbon, hydrogen, oxygen and nitrogen from the soil and air and turn them into complex things like fats and proteins. These will be eaten by an animal and will be retuned in waste products produced by the animal or when the animal dies. The Waste and dead animal will be decomposed by microorganisms.
103
What are the best conditions for microorganisms to digest?
Warm moist conditions. Many work well with lots of oxygen. | Compost bins provide these conditions.
104
What is the only way in which carbon can leave the air in the carbon cycle?
Photosynthesis. Plants and algae will remove CO2 which will then be used by animals when they are eaten.
105
How does carbon get to the air in the carbon cycle?
Animals and plants will respire producing CO2 When animals die they will be decomposed by detritus feeders and microorganisms producing CO2 as they respire. Waste is also broke down in this way. Wood and fossil fuels will be burnt producing CO2
106
Where do proteins come from?
Meat fish eggs cheese.
107
What diseases do bacteria cause?
Cholera, food poisoning, typhoid.
108
What do viruses cause?
Flu, cold, measles, mumps, rubella, AIDs.
109
What type of white blood cell produce antibodies?
Lymphocytes.
110
What are antibodies made of?
Proteins.
111
How do antibodies kill pathogens?
They bind them to kill them. | They coat them and bind them together meaning they are easily ingested.
112
What type of white blood cell ingest pathogens?
Phagocytes.
113
What can a vaccine contain?
Live pathogens that have been made harmless. Fragments of pathogens. Dead pathogens.
114
What do antibodies to stop pathogens?
Penicillin breaks down cell walls. | Others stop protein synthesis or DNA replication.
115
What is positive or negative tropism?
Positive. The plant grows towards the stimulus. The other is opposite.
116
How are ions lost?
In sweat and in urine.
117
What factors can effect the rate of metabolism?
Age, sex, exercise, proportion of muscle in body, inherited factors.
119
Why would a new strain of antibiotic resistant bacteria spread rapidly in a population?
Antibiotics can't kill them They reproduce. The population of them increases.
120
What is a nerve?
A collection of neurones.
121
How many genes in a human?
30,000

X Biology (6 decks)

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