Unit 1A - Human Biology Flashcards
What five things make up a balanced diet?
Carbohydrates, fats, protein, fibre and vitamins/mineral ions
Where do humans get their energy from?
Food
Why do we need to eat carbohydrates?
To release energy
Why do we need to eat fats?
To keep warm and release energy
Why do we need eat protein?
Growth, cell repair and cell replacement
Why do we need to eat fibre?
To keep everything moved smoothly through your digestive system
Why do we need to eat vitamins and mineral ions?
To keep your skin, bones, blood and everything else healthly, to prevent deficiency diseases
What is your metabolic rate?
The rate at which the chemical reactions in your body take place
Which three people are likely to have a faster metabolic rate and why?
- ) People with a higher proportion of muscle to fat in their bodies, because muscles need more energy than fatty tissue
- ) Bigger people because you have more cells which require more energy
- ) Men over women because they are larger and have more muscle
How can regular exercise boost your metabolic rate?
It builds muscle and muscles require more energy than fatty tissue and therefore increasing your metabolic rate
How does activity level affect your diet?
If you do little exercise you need less energy, so less fat and carbohydrate in your diet
You health is affected by what three things?
Unbalanced diet, not getting enough exercise and inherit tied factors
What does it mean to be malnourished?
It is people whose diet is badly out of balance
Are malnourished people thin?
No they can be fat or thin
What’s the difference between malnourishment and starvation?
Starvation is not getting enough food of any sort and malnourished is just a really unbalanced diet
Eating too much of which food group can lead to obesity?
Excess carbohydrate or fat
What is obesity defined as?
20% or more over the maximum recommended body mass
What four things can cause obesity?
Hormonal problems, bad diet, over eating and a lack of exercise
What five health problems can being obese cause?
Arthritis, type 2 diabetes, high blood pressure, heart disease and it is a risk factor of some kinds of cancer
Eating too much of what can cause an increase in your blood cholesterol level?
Saturated fats
Eating too much salt can cause what?
High blood pressure and heart problems
Malnutrition causes by a lack of food can cause?
Slow growth in children, fatigue, poor resistance to infection and irregular periods in women
What are deficiency diseases caused by?
A lack of vitamins or minerals
What is scurvy and how is it caused?
Lack of vitamin c, a deficiency disease that causes problems with skin, joints and gums
How can people be fit but not healthy?
You can be physically fit and slim but be malnourished because your diet isn’t balanced
Why does exercising mean you are less likely to suffer from health problems such as obesity?
Exercise increases the amount of energy used by the body and decreases the amount of stored fat, it also builds muscle boosting your metabolic rate
What inherited factor can affect your metabolic rate?
An under active thyroid gland is inherited and can lire the metabolic rate
What four things would tell you claims about slimming products are true?
- ) if the report is a scientific study
- ) if it was written by a qualified person not contacted to the people selling it
- ) if the sample of people asked or tested on is large enough to give reliable results
- ) if there has been other studies which found similar results
How do you lose weight?
Take in less energy than you use, eat less carbohydrate and fats (so you take in less energy) and do more exercise (so that you use more energy)
What is a pathogen?
It is microorganisms that enter the body and cause disease
Are bacteria or viruses living cells?
Bacteria are very small living cells
Viruses are not cells
What’s the difference in size of a virus compared to bacteria?
Virus is 1/100th the size of a bacterium, and so a lot smaller
How does a virus reproduce?
They replicate themselves by entering your cells and using the cell to make copies of themselves until the cell bursts releasing the new virus
How does bacteria make you feel ill?
Damaging your cell and by producing toxins
How does a virus make you feel ill?
Through cell damage
What is in the respiratory tract to help the bodies defence system?
Hairs and mucus to stop things getting into the body
How does your body try to prevent microorganism getting in through cut?
Small fragments of cells called platelets help the blood to clot quickly to seal the wound not allowing microorganisms to enter
What is the cell called that helps to clot blood?
Platelets
What are the three ways that white blood cells can kill pathogens?
Consuming them, producing antibodies, or producing antitoxins
How to white blood cells consume pathogens?
They simply engulf and foreign cells and digest them
How do antitoxins help the defence system?
They counteract toxins produced by the invading bacteria
Why can’t antitoxins work against virus’s?
Because viruses don’t produce toxins like bacteria does
How to antibodies help kill invading cells?
Every invading cell has unique antigens on its surface, when a white blood cell comes across a foreign antigen they will start go produce proteins called antibodies to lock onto and kill the invading cells
Why can’t antibodies kill any invading cell?
They are specifically to lock onto one type of antigen and so they would not able to kill any invading cell
What happens is a person is infected with the same pathogen again?
The white blood cells will recognise the antigen and rapidly produce antibodies to kill it
What does a vaccination prevent?
Any future injections
What do vaccinations involve?
Injecting small amounts of dead or inactive mircrooanisms, these carry a hyphens which cause your body to produce antibodies to attack them, even though the microorganism is harmless. This means is the live microorganism ever was to appear again then your white blood cells can rapidly mass produce antibodies to kill off the pathogen.
What does the MMR vaccine contain?
Weakened versions of the viruses that cause measles, mumps and rubella
Why do you need booster injections?
As some vaccinations wear off and so a booster may be given to increase the levels of antibodies again
What are two pros of vaccinations?
They have helped to control lots of infectious diseases that were once common in the UK and they prevent big outbreaks of the disease
What diseases were once common in the UK before vaccinations?
Polio, measles, whooping cough, rubella, mumps, tetanus and small pox
How do vaccinations help to prevent epidemics?
If a large percentage of the population is vaccinated, that means even people who aren’t vaccinated are less likely to catch the disease because there are fewer people able to pass it on
What are two cons of vaccinations?
They don’t always work and give you immunity, you can sometimes have a bad reaction to a vaccine
What type of drug relieves symptoms?
Pain killers just relieve pain they don’t tackle the cause of the disease
What type of drugs reduced symptoms?
Cold remedies reduced symptoms but don’t cure the cold
How are antibiotics different to pain killers?
Pain killers just relieve pain where as antibiotics kill or prevent yeh growth of the bacteria causing the problem
Why is it important to use the right antibiotics when treating an illness?
Different antibiotics kill different types of bacteria
Why can’t you use antibiotics to cure the flu or a cold?
They are both viruses, viruses reproduce using your own body cells which means you can’t destroy them us using antibiotics whiteout killing the body’s cells
How do you get bacteria that is resistant to antibiotics?
Bacteria can mutate, sometimes the mutations cause them to be resistant to antibiotics, so when you get an infection some of the after is may be resistant to antibiotics, this means when you treat the infection only the non resistant strains of bacteria will be killed, so the individual resistant bacteria will survive and reproduce creating more bacteria that is resistant to antibiotics
What is an example of an antibiotic resistant bacteria?
MRSA
How are doctors tying to slow down the rate of development of resistant strains of bacteria?
By not over prescribing antibiotics
What can microorganisms be grown in?
In a culture medium
What is in a culture medium?
An agar jelly plate containing the carbohydrates, minerals, proteins and vitamins bacteria needs to grow
How do you grow bacteria in a petri dish?
Inoculating loops are used to transfer microorganisms to the culture medium and the microorganisms then multiply. Paper disks are soaked in different types of antibiotics and placed on top of the culture medium. All non resistant strains of bacteria will die around the disks. The more effective an antibiotic is the bigger the circle will be
How and why do the culture medium and inoculating loops need to be sterilised before use?
They are passed through a flame so that unwanted microorganism don’t grow and affect the results
Why does the petri dish need to have a lid?
To stop any microorganism in the air contaminating the culture
Why and at what temperatures are microorganism grown in schools?
At about 25c because harmful pathogens aren’t likely to grow at this temperature
Who cut deaths by using antiseptics?
Ignaz Semmelweis
While Semmelweis was working in Vienna General Hospital in the 1840s what did he notice?
Women were dying in huge numbers after childbirth from a disease called puerperal fever
How did Semmelweis believe doctors where spreading the disease and how did he solve it?
They were spreading the disease through their unwashed hands and the bacteria and their hands, he told doctors entering to wash their hands in an antiseptic solution
How much did Semmelweis cut the death rate of the women on his ward?
From 12% to 2%
Why was Semmelweis’s idea of washing hands in an antiseptic solution stop when he left the hospital?
They didn’t know about bacteria being a part in causing disease until 20 years later so he couldn’t prove his idea and so his methods were dropped when he left
Why is it it more easy to pass on an antibiotic resistant bug?
People who have become infected can’t get rid of it easily and so there is more chance of passing the infection on
What is the biggest worry about bacteria at the moment?
It can mutate to produce new strains, which could be anti biotic resistance and so current treatments wouldn’t work, or the new strain could be completely new and so no one old be immune to it, this means the new strains can spread rapidly in the population and even cause an epidemic
What is the biggest worry about viruses at the moment?
Viruses mutate often and so it is hard to develop vaccines against the, because the change in their DNA can lead to them having different antigens and so old vaccinations wouldn’t work. The virus could spread easily and be ever more deadly and infectious after mutating
What does the nervous system allow you to do?
React to what goes on around you
What do sense organs detect?
Stimuli
What is a stimulus?
Change in your environment which you may need to react to
How many sense organs do you have?
Five
What are the five sense organs?
Eyes, ears, nose, tongue and skin
What do sense organ contain?
Receptors
What is a receptor?
A receptor is a group of cells which are sensitive to a stimulus, they change stimulus energy into electrical impulses
Name eight stimulus.
Iight, sound, touch, pressure, pain, chemical or a change in position or temperature
What receptors are in eyes?
Light receptors
What receptors are in ears?
Sound and balance receptors
What receptor is in the nose?
Smell receptors
What receptor is in the tongue?
Taste receptor
What are the receptors in the skin sensitive to?
Touch, pressure, pain and temperature change
What stimuli are smell and taste receptors sensitive to?
Chemical stimuli
What is a sensory neurone?
Nerve cells that carry signals as electrical impulses from the receptor in the sense organs to the central nervous system
What is a relay neurone?
The nerve cells that carry signals from sensory neurones to motor neurones
What is a motor neurone?
The nerve cells that carry signals from the central nervous system to the effector muscles or glands
What is an effector in the nervous system?
Muscles or glands are known as effectors and they respond in different ways, muscles contract in response to a nervous impulse whereas glands secrete hormones
What does CNS stand for?
The central nervous system
What is the central nervous system?
Where all the information from the sense organs is sent, and where reflexes and actions are co ordinates
What does the central nervous system consist of?
The brain and spinal cord
What do neurones do?
Transmit information as electrical impulse to and from the CNS
What is the connection between two neurones called?
A synapse
How is the nerve signal transferred across a synapse?
By chemicals which diffuse across the gap
What do reflexes prevent?
Injury
What is a reflex?
An automatic response to certain stimuli
What reflex happens if someone shines a bright light in your eyes?
Pupils get smaller to allow less light into the eye to stop them getting damaged
The passage of information in a reflex from the receptor to the effector is called?
A reflex arc
Does the reflex arc go through the central nervous system?
Yes
What happens during a reflex arc?
A stimulus is detected by a receptor, the impulses are sent along a sensory neurone to the CNS, impulses are passes to a relay neurone through diffusion over a synapse, these impulses then travel through the really neurone and to a motor neurone via a synapse, the impulses them travel along the motor neurone and to the effector where a response then happens
What do reflexes bypass and why?
Your conscious brain to make it faster and reduce injury
What is a hormone?
Chemical messengers which travel in the blood to activate target cells
Hormones are produced in and secreted by?
Glands
How to hormones have effect for?
They have relatively long lasting effects
What are two glands that release hormones during the menstrual cycle?
The pituitary gland and the ovaries
What two hormones are produced in the pituitary gland and are involved in the menstrual cycle?
FSH and LH
What hormone is produced in the ovaries and is involved in the menstrual cycle?
Oestrogen
What the four main differences between nerves and hormones?
Nerves - fast action, act for a very short time, act on a precise area
Hormones - slower action, act for a long time, act in a more general way
Are hormones fast or slow?
Slow action
Do nerves act for a short time or a long time?
Short time
Do hormones act on a very precise area or in a more general way?
In a more general way
What is the menstrual cycle?
The monthly release of an egg from a woman ovaries and the build up and breakdown of the protective lining of the uterus
How many stages are in the menstrual cycle?
Four
What happens in stage 1 of the menstrual cycle?
The lining of the uterus breaks down and the bleeding starts
What happens during stage 2 of the menstrual cycle?
The lining of the uterus builds up again into a thick spongy layer full of blood vessels ready to receive a fertilised egg
What happens during stage 3 of the menstrual cycle?
An egg is released from the ovary
What happens during stage 4 of the menstrual cycle?
The wall is then maintained, if no fertilised egg has landed in the uterus the lining will start to break down again
How long does each stage of the menstrual cycle last?
Stage 1 - 4 days
Stage 2 - from day 4 to day 14
Stage 3 - at day 14
Stage 4 - for about 14 days, so from day 14 to day 28
At which stage does the lining of the uterus break down in the menstrual cycle ?
Stage 1
At which stage is an egg released in the menstrual cycle?
Stage 3
At which stage is the lining of the wall maintained in the menstrual cycle?
Stage 4
At which stage does the lining of the uterus build up again in the menstrual cycle?
Stage 2
What are the three main hormones involved in the menstrual cycle?
FSH, LH and Oestrogen
What does FSH stand for?
Follicle - Stimulating Hormone
What does LH stand for?
Luteinising Hormone
Where is FSH produced?
In the pituitary gland
Where is Oestrogen produced?
In the ovaries
Where is LH produced?
In the pituitary gland
What does FSH do?
Causes an egg to mature in one of the ovaries and stimulates the ovaries to produce oestrogen
What does oestrogen do?
Causes pituitary gland to produce LH and inhibits further release of FSH
What does LH do?
Stimulates the release of an egg in stage 3 of the menstrual cycle
Other than FSH, LH and oestrogen what is another hormone involved in the menstrual cycle?
Progesterone
What hormones does the pill contain?
Oestrogen and progesterone
Why is oestrogen used in the pill?
If oestrogen is taken every day to keep the level of it permanently high it inhibits the production of FSH and after a while egg development and production stop
Why is progesterone used in the pill?
It stimulates the production of thick cervical mucus which prevents any sperm getting to the egg
Why does the pill contain less oestrogen that it used to?
The oestrogen was thought to be causing bad side effects like blood clots
What’s an advantage and disadvantage of the progesterone only pill?
It has fewer side effects than the pill but it isn’t as effective
What are two pros of using the pill?
- ) it’s over 99% effective at preventing pregnancy
2. ) it reduces the risk of getting some types of cancers
What are three cons if using the pill?
- ) it isn’t 100% effective so there is still a slight chance of getting pregnant
- ) it can cause side effects
- ) it doesn’t protect against STDs
What are some of the side effects of the pill?
Headaches, nausea, irregular menstrual bleeding and fluid retention
Hormones can be used to reduce fertility as well as?
Increasing it
Which hormones can be injected to help increase fertility?
FSH and LH
What do low levels of FSH cause?
No eggs are matures or released so a women can’t get pregnant
How does injecting FSH and LH help to increase fertility
It stimulates egg release in their ovaries
What is a pro of injecting FSH and LH to increase fertility?
It helps a lot of women or get pregnant when they otherwise couldn’t
What are two cons of injecting FSH and LH to increase fertility?
- ) It doesn’t always work, some women have to have in done many times which is expensive
- ) too many eggs could be stimulated resulting in unexpected multiple births
What can IVF help couples to do?
Have children
What does IVF stand for?
In vitro fertilisation
What happens during IVF?
It involves collecting eggs from the women ovaries and fertilising them in a lab using the mans sperm, these are then grown into embryos, once the embryos are tiny balls of cells, one or two of them are transferred to the women uterus improving the chance of pregnancy
What is given before IVF and why?
FSH and LH are given before egg collection to stimulate egg production
What is a pro of IVF?
It can help infertile couples have a child who otherwise couldn’t
What are three cons of IVF?
- ) some women have a strong reaction to the hormone, abdominal pain, vomiting, dehydration
- ) some reports saying there is increased risk of cancer due to hormonal treatment
- ) multiple births can happen if more than one embryo grows into a baby
What is the plant growth hormone called?
Auxin
What does auxin control?
He growth near the roos of shoots and root
Auxin controls the growth of the plant in response to what three things?
Light, gravity and moisture
If a plant grows a certain way in a response to light what is it called?
Phototropism
If a plant grows a certain way in response to gravity what is it called?
Gravitropism
What is cell elongation?
When a cell grows
If the tip of a shoot is removed why may the shoot stop growing?
As there is not auxin available
What does extra auxin causes in shoots and roots?
Promotes growth in shoots
Inhibits growth in roots
What happens when a shoot tip is exposed to light?
More auxin accumulates on the side that’s in the shade than the side that’s in the light, this makes the cell elongate faster on the shaded side bending the shoot towards the light
What happens when a shoot tip is growing sideways?
More auxin accumulates at the side closest to gravity and so the lowest side, this causes the lower side to elongate faster, bending the shoot upwards away from gravity
What happens if a root tip is growing sideways?
More auxin will accumulates on it’s lower side, but in roots the extra Austin inhibits growth and so the cells on top elongate faster, bending the root downwards towards gravity
What happens is there is uneven amounts of moisture either side of a root?
More auxin will accumulates on the side with more moisture, as in roots auxin inhibits growth it causes the other side to elongate faster, bending the root towards the moisture
How can plant hormones be used as a weed killer?
Most weeds in crop fields have broad leaves, where as the crops have much narrower leaves, selective weed killers are made of plant hormones that only affect the broad leaved plants, killing the weeds but un harming the crops
How can plant hormones be used to make plant cuttings grow in soil and why is it useful?
If you add rooting powder which contains the plant hormone auxin they will produce roots rapidly and start growling as new plants, this helps the growers to produce lots of clones of good plants quickly
What is homeostasis?
All the functions of your body which try to maintain a constant internal environment
What are the bodily levels that need to be controlled?
Ion content, water content, sugar content and temperature
What is ion content regulated by?
The kidneys
Give an example of a ion that is regulated by the kidneys?
Sodium Na+
What happens if food contains too much of any kind of ion?
Then the excess ions need to be removed either lost in sweat or the kidney will remove the excess from the blood
What ways is water lost from the body?
Through the skin as sweat, via the lungs in breath and via the kidneys are urine, some water is also lost in faeces
What happens to the balance between sweat and urine on a cold day?
On a cold day you don’t sweat much so you’ll produce more urine
Why is your urine pale on a cold day?
More water is lost through urine and so the waste it carries will be more dilute
What happens to the balance of sweat and urine on a hot day?
You sweat a lot and so you will produce less urine
Why is your urine a deeper colour on a hot day?
As you produce less urine it will be more concentrated and so a deeper colour
Other than how cold or hot a day is what does the balance between sweat and urine depend on?
Whether you are exercising or not, as you also lose more water through your breath when you exercise because you breath faster
Body temperature is controlled by the?
Brain
What temperature to enzymes work best in the body?
37c, and so this is the temperature your body tries to maintain
The part of your brain that controls body temperature is sensitive to?
Blood and skin temperature
Eating foods that contain what put glucose into the blood?
Carbohydrates
What hormone helps to maintain the right level of glucose in your blood?
Insulin
What usually removes glucose from the blood?
The normal metabolism of cells
What do drugs do to your body?
Alter and interfere with the chemical reactions that go on within your body
Name four very addictive drugs
Heroin, cocaine, nicotine and caffeine
If you are addictive to drugs and you stop taking them what can it cause?
Physical withdrawal symptoms
What the types of drugs are there?
Medicinal, recreational or performance enhancing
Give an example of a medicinal drug than is used for medicine?
Antibiotics
What are recreational drugs for?
Fun
What are perfume enhancing drugs?
To improve someone’s performance in a sport, make you better at it
Name two performance enhancing drugs and what they do
Anabolic steroids - increase muscle size
Stimulants - increase heart rate
What is a negative health effect of steroids?
High blood pressure
What are two reason against using performance enhancing drugs?
- ) unfair for people to gain an advantage by taking drugs and not training
- ) athletes may not be fully informed of the serious health risks of the drugs they take
What are two reasons for taking performance enhancing drugs?
- ) athletes have the right to make their own decision on whether taking drugs is worth the risk or not
- )drug free sport isn’t really fair anyway as different athletes have access to different training facilities, coaches and equipment
What are statins?
Prescribed drugs that lower the risk of heart and circulatory disease
Who and what original research was there into statins?
It as as done by the government, by scientists who had no connection to the manufactures
If a control group is used what does it make the results?
Reproducible
Scientists have investigates whether the chemicals in canna is smoke cause what problems?
Mental health problems
What are the main three stages in drug testing?
- ) drugs are tested on human cells and tissues in lab
- ) drugs are then tested on live animals
- ) finally it is tested on human volunteers in a clinical trial
Why are drugs tested on human cells and tissue in a lab first?
To see whether it kills human cells and if it is safe or not
Why can’t you test drugs for blood pressure on human cells and tissues?
Because the drug affects the whole body and so it wouldn’t be affected on cells
Why is the drug tested in live animals secondly?
To see whether the drug works, to find out about its toxicity and to find the best dosage
What does the law in Britain day about testing drugs on live animals?
That any new drug must he tested on two different live mammals
What is one reason for both, why are people are for and against animal testing?
Against - it is cruel to test on animals and some animals are so different to humans it is pointless
For - safest way to make sure a drug is safe before giving it to humans
During clinical trials why is the drug first tested on healthy volunteers?
To make sure it doesn’t have any harmful side effects when the body is working normally
In clinical trials who do they test on after healthy volunteers?
People who suffer from the illness
During clinical during why is the drug tested on people who have the illness?
To find the optimum dose
What is an optimum dose?
A dose that is the most effective and has few side effects
During clinical trials what two groups are the patients put into?
They are put into two different groups one is given the new drug and one is given the placebo
What is a placebo?
A substance that looks like the drug being tested but doesn’t actually do anything
Why do doctors use a placebo when testing new drugs?
To see the actual difference the drug makes, it allows for the placebo effect
What does it mean if clinical trials are blind?
The patient in the study doesn’t know whether thery getting the drug or the placebo, and sometimes even the doctor doesn’t know until the results have been gathered
What is an example how drugs have gone wrong in the past because they haven’t been thoroughly tested?
Thalidomide
When was thalidomide developed?
In the 1950s
What was thalidomide used for?
Intended as a sleeping pill, and was tested for that use. But later is was found to be effective at relieving mourning sickness in pregnant women
What happened as a result of thalidomide not being tested as a drug for mournings sickness?
As it was tested it wasn’t know that it could pass through the placenta and affect the fetus, causing abnormal limb development
How many babies were affected by thalidomide?
About 10 000
Of the 10 000 babies affected by thalidomide how many survied?
About half of them
What happened after they realised what thalidomide was causing?
It was banned and more rigorous testing procedures were introduced
What has thalidomide been used to treat more recently?
Leprosy and other diseases
What two main classes can illegal drugs be divided into?
Hard and soft
What are hard drugs thought to be?
Seriously addictive and generally more harmful
What are six reason some people choose to use recreational drugs?
For enjoyment, relaxation, stress relief, to get stoned, for inspiration or because of personal issues that has lead to taking drugs
Some studies link cannabis and what together and why?
Hard drug use because almost all users of hard drugs have tried cannabis first
What are the main three opinion on the drug cannabis and it leading to hard drug use?
- ) It is a stepping stone
- ) Cannabis is a gateway drug
- ) It’s all down to genetics whether you are likely to take drugs and get addicted to drugs
What is the meant by cannabis being a stepping stone and a gateway drug?
Steeping stone - the effects of cannabis create a desire to try harder drugs
Gateway drug - cannabis brings people into contact with drug dealers
Name two legal recreational drugs?
Tobacco and alcohol
What are three negative effects of smoking?
- ) smoking causes disease of the heart, blood vessels and lungs
- ) tobacco smoke also causes cancer
- ) nicotine is a drug found in cigarettes and it is very addictive so it is hard to stop smoking
What are four negative effects of alcohol?
- ) alcohol affects the nervous system and slow down the body’s reactions
- ) too much alcohol leads to impaired judgement, poor coordination and unconsciousness
- ) excessive drinking can cause livid disease and brain damage
- ) alcohol is also addictive
Do tobacco and alcohol or illegal drugs have a bigger impact on the UK?
Tobacco and alcohol as so many people take them
