B3

Question 1

what are pathogens?
what 2 things can be infected with pathogens?

Answer 1

-Pathogens are microorganism’s that cause infectious diseases
-Both plant and animal can be infected

Question 2

what is bacteria and what does it do to your body?

Answer 2

-Bacteria are very small cells which can reproduce rapidly in your body
-They make you feel ill by producing toxins that damage your cells and tissues

Question 3

what are viruses ‘not’?
what do they do in the body ie (cells)?

Answer 3

-They are not cells
-They reproduce rapidly inside your body
-They replicate themselves in the cells to produce many copies of themselves.The cell will usually burst releasing new viruses.Cell damage will make you feel ill

Question 4

what are protist’s?
what are some protist’s and what does it do?

Answer 4

-They are single-celled eukaryotes
-Some are parasites.Parasites live on or inside other organisms and can cause them damage.They are often transferred to the organism by a vector which doesn’t get the disease itself

Question 5

what is fungi?
what is hypahe?
what are the causes?

Answer 5

-They come different shapes could be unicellular or multicellular.
-Others have a body which is made up of hyphae (thread like structure)
-Hyphae can grow and penetrate human skin and the surface of plants causing disease’s
-Hyphae can produce spores which be spread to other animals and plants

Question 6

what are three ways pathogens can be spread and the examples?

Answer 6

1) Water-cholera is a bacterial infection that’s spread quickly by drinking water contaminated with the diarrhoea of the other sufferer’s

2)Air-pathogens can be carried in the air and then breathed in.Through droplets produced when you cough or sneeze eg influenza virus

3)Direct contact-By touching contaminated surfaces eg athlete’s foot is a fungus makes skin itch and flake off.Spread by touching the same things as an infected person eg shower floors

Question 7

what is the difference between communicable and non-communicable disease?

Answer 7

-Communicable can be spread from person to person
-Non-communicable cannot be passed from person to person

Question 8

how is measles spread ?
what are sympton’s?
what can it lead to?
how can you prevent?

Answer 8

-Viral disease
-Spread by droplets from an infected person sneeze or cough’s
-Symptons: Red skin rash and fever
-It can be fatal for eg can lead to pneumonia or inflammation of the brain
-Most people are vaccinated against it from young

Question 9

what is HIV?
what are the symptons?
what is antiretroviral drugs?
where does the vrius attack?
what happens if the body immune system is badly damaged?

Answer 9

-Spread by sexual contact or exchanging body fluids such as blood.This can happen when you share needles when taking drugs
-They are like flu-like symptons
-By using antiretroviral drugs.These stop the virus from replicating
-The virus attacks in the immune cells
-If the body’s immune system is badly damaged it can’t cope with other infection’s or cancer’s.At this stage the virus is known as late stage hiv or aids

Question 10

what is TMV?(tobacco mosaic virus)?
what does it cause?

Answer 10

-Tobbacco mosaic virus it affects many species of plants
-It causes a mosaic pattern on the leaves of the plants and plants become discoloured
-This discolouration means plants can’t carry out photosynthesis so virus affects growth

Question 11

what is fungal disease rose black spot?
how can it spread?
how can it be treated?

Answer 11

-Rose black spot is a fungus that causes purple or black spots to develop on leaves of rose plants,the leaves can turn yellow and fall off
-This means less photosynthesis can happen so the plant doesn’t grow well
-It spreads through the environment in water or wind
-It can be treated by stripping the plants of it’s affected leaves.These leaves can be destroyed so that fungus doesn’t spread

Question 12

what is the protist malaria?
how can it happen?
what are the sympton’s?
how can the spread of malaria reduce?

Answer 12

-Malaria is caused by a protist
-Malarial protist life cycle takes place inside the mosquito
-The mosquitoes are vectors they pick up the malarial protist when they feed on an infected animal
-Every time a mosquito feeds on another animal it infects it by inserting the protist into the animal’s blood vessel.
-Malaria causes repeating fever.It can be fatal
-It can be reduced by stopping the mosquitoes from breeding
People have mosquito nets and use insecticides

Question 13

what is salmonella?
what are the symptons?
how are these symptons caused?
what have the UK done?

Answer 13

-Salmonella is a type of bacteria that causes food poisoning
-Symptons- fever,stomach cramps,vomiting and diarrhoea
-These symptons are caused by toxins that the bacteria produce
-You can get by eating food thats been contaminated with salmonella bacteria
-In the uk are vaccinated against salmonella to control the spread

Question 14

what is gonorrhoea?
what are the symptons?
how is it treated?
how to prevent the spread?

Answer 14

-Its a sexually transmitted disease passed by sexual contact eg unprotected sex
-Caused by a bacteria
-Symptons pain when urinating.Thick yellow or green discharge
-Treated by antibiotic
called penicillin this has become difficult strains of bacteria have become resistant to it
-use barrier methods of contraception eg condoms
-use antibiotics

Question 15

What are four things to prevent the spread of disease?

Answer 15

1) Being hygienic- Using simple hygiene methods. eg washing your hands before preparing food

2) Destroying vectors- getting rid of the orgnasims that spread disease.Vectors are insects can be killed from insecticides destoying habitat so they can no longer breed

3)Isolating infected individuals- if you isolate someone who has a communicable disease can prevent the spread of passing it on

4)Vaccination- people and animals against communicable diseases means that they are less likely to develop the infection and then pass it on.

Question 16

what are the 4 features of the human body against pathogen’s?

Answer 16

-Skin=acts as a barrier.It also secretes antimicrobial substances which kill pathogens
-Hairs and mucus= In your nose that trap particles that could contain pathogens
-Trachea and bronchi= secrete mucus to trap pathogens and are lined with cilia (hair like structures) which waft the mucus up to the back of the throat which can be swallowed
-Stomach=produces hydrochloric acid.Kills pathogens that it make that far from the mouth

Question 17

what is the most important part of your immune system?

what is the 3 line of attack for white blood cells?

Answer 17

-Pathogens enter the IMS
-Most important is the white blood cells they travel in your body and they are constantly patrolling for microbes.When they came across and invading microbes they have 3 lines of attack

3 Lines of attack
1) Consuming them=they can engulf foreign cells and digest them this is called phagocytosis

2)Producing antibodies=
every invading pathogen has unique molecules (antigens) on its surface.When some types of white blood cells come across as foreign antigen they will start to produce proteins called antibodies to lock onto the invading cells so that they can be found and destroyed by other white blood cells.The antibodies produced are specific to that type of antigen-won’t lock onto any others.Antibodies are then produced rapidly and carried around the body to find all similar bacteria or virus.If the person gets infected with the same pathogen then the white blood cells will rapidly produce the antibodies to kill it the person is naturally immune to that pathogen and won’t get ill

3)Producing antitoxins-These counteract toxins produced by the invading bacteria

Question 18

what is a vaccination?
what if happens if the same pathogens appears again?

Answer 18

-Involves injecting small amounts of dead or inactive pathogens into the body to stimulate the white blood cells to produce antibodies
-If the same pathogen appears again the white blood cell can rapidly produce the correct antibodies preventing infection

Question 19

what are the pros and cons of vaccination?

Answer 19

PROS: Vaccines have helped control lots of communicable diseases that were once common in the UK.Big outbreaks of disease called epidemics can be prevented if a large percentage of the population get vaccinated.That way even the people who aren’t vaccinated are unlikely to catch the disease.But if a big amount aren’t vaccinated disease will spread quickly and lots of people will be ill at the same time.

CONS: vaccines don’t always work-sometimes they don’t give you immunity.You can sometimes have a bad reaction to a vaccine eg swelling.But they are rare

Question 20

what are painkillers and eg?
what are antibiotics and eg?
what don’t antibiotics treat and why?
what has the use of antibiotic done?

Answer 20

-They are drugs eg aspirin They help reduce the symptons and they don’t tackle the cause or disease or kill pathogens.
-Antibiotics they actually kill or prevent the growth of bacteria without killing your body tissues .
-Different antibiotics kill different types of bacteria
-They don’t treat viruses because viruses reproduce using your body cells which makes it very difficult to develop drugs that destroy just the virus without killing the body cells.
-The use of antibiotic have greatly reduced the number of deaths from communicable diseases caused by bacteria

Question 21

what can bacteria do and what does it cause?

Answer 21

-Bacteria can mutate (change).This can cause them to be resistant and not be killed by antibiotics

Question 22

what do plants produce?
what can some of chemicals be used as ?
what are eg for plants be used as traditional cures?
what is one drug extracted from microorganisms?
what did alexander fleming discover?

Answer 22

-Plants produce a variety of chemicals to defend themselves against pests and pathogens
-Some of these chemicals can be used as drugs to treat humans diseases or relieve symptons
-Aspirin is used as a painkiller and to lower fever.It was developed from a chemical found in willow
-Digitalis is used to treat heart conditions it was developed from a chemical found in foxgloves
-Alexander fleming was clearing out some petri dishes containing bacteria he noticed that one of dishes of bacteria had mould on it and the area around mould was free of bacteria
-He also found mould on the petridish was producing a substance that killed bacteria-substance was penicillin

Question 23

what are three main stages in drug testing?

Answer 23

FIRST PART:
-In preclinical testing drugs are tested on human cells and tissues in a lab
-However you can’t use human cells and tissues to treat drugs that affect whole or multiple body systems
SECOND PART:
-The next step in preclinical testing is to test the drug on live animals.This is to test the efficacy ((whether drugs work and produces the effect your looking for)) to find out about it’s toxicity (how harmful it is)
and to find the best dosage (how often it should be given)
-The law in Britain states that any new drug must be tested on 2 different mammals.Some people think it’s cruel to test on animals and others think its the safest way to make sure a drug isn’t dangerous for humans
THIRD PART:
-If the drug passes the test on animals then it’s tested on human volunteers in a clinical trial
-First the drug is tested on healthy volunteers.This is to make sure that it doesn’t have any harmful side effects when the body is working normally.At the start of the trial a very low does of the drug is given and this is gradually increased.
-If the results on the healthy volunteers is good the drugs can be tested on people suffering from illness.The optimum dose is found this is the does of drug that is the most effective and has few side effects