Chapter 3 - Infection And Response

Question 1

What are pathogens

Answer 1

Pathogens are microorganisms that into the body and cause disease

Question 2

What type of disease do they cause

Answer 2

Because communicable diseases which are infectious

Both plants and animals can be infected by pathogens

Question 3

What are the different types of pathogens

Answer 3

Bacteria
Viruses
Protists
Fungi

Question 4

How does bacteria make you feel ill

Answer 4

They can make you feel ill by producing toxins that damage your cells and tissue

Question 5

How do you viruses make you feel ill

Answer 5

They can reproduce rapidly inside your body. They live inside your cells and replicate themselves using the cells machinery to produce many copies of themselves. The cell will usually burst releasing all the new viruses.

This cell damage is what makes you feel ill

Question 6

What are protists and what did they do

Answer 6

There are lots of different types of protests. They are all eukaryotes and most of them are single celled

Some protests are parasites. Parasites live on the inside other organisms and can cause them damage. They are often transfer to the organism by vector which doesn’t get the disease itself e.g. an insect Carries the protest.

Question 7

What is fungi?

What does it do?

Answer 7

Some fungi are single celled. Others have a body which is made up of hyphae which is a thread like structure.

These hyphae can grow and penetrate human skin and the surface of plants causing diseases

Question 8

What are the different ways that pathogens can be spread?

Answer 8

Water-some pathogens can be picked up by drinking or bathing in dirty water e.g. cholera

Air-pathogens can be carried in the air and can be breathed in. Some airborne pathogens are carried in the air and droplets produced when you cough or sneeze

Direct contact-some pathogens can be picked up by touching contaminated surfaces, including the skin e.g. athletes foot

Question 9

What is measles?

How was it caused?

Answer 9

Measles is a viral disease. It is spread by droplets from an infected persons sneeze or cough

People with measles developed a red skin rash and a show signs of fever

Measles can be serious or even fatal if there are complications. E.g. measles can sometimes lead to pneumonia or brain infection cord encephalitis

Most people are vaccinated against measles when they’re young measles is a viral disease. It is spread by droplets from an infected persons sneeze or cough

People with measles developed a red skin rash and of show signs of fever

Measles can be serious or even fatal if there are complications. E.g. measles can sometimes lead to pneumonia or brain infection called encephalitis

Most people are vaccinated against measles when they’re young

Question 10

What is HIV

How was it caused

Answer 10

HIV is a virus spread by sexual contact or by exchanging bodily fluids such as blood. This can happen when people share needles when taking drugs

HIV initially causes flu like symptoms for a few weeks. Usually, the person doesn’t then experience any symptoms for several years. During this time, HIV can be controlled with Antiretroviral drugs. The stop the virus replicating in your body

The virus attacks the immune cells

If the body is immune system is badly damaged, it can’t cope with other infections or cancers. At this stage the virus is known as late stage HIV infection or AIDS

Question 11

What is tobacco mosaic virus

What does it calls

Answer 11

Tobacco mosaic virus or TMV is a virus that affects many species of plants e.g. tomatoes

It causes the Mosaic pattern on the leaves of the plant-part of the lease has become discoloured

The discolouration means the plant can’t carry out photosynthesis so the virus affect growth

Question 12

What is rose blackspot disease

What does it cause

Answer 12

Rose blackspot is a fungus that causes purple or black spots to develop on the leaves of rose plants. The leaves can then turn yellow and drop off

This means that less photosynthesis can occur so the plant does it grow very well

It spreads through the environment in water or by the wind

Gardeners can treat the disease using fungicides and by stripping the plant of its affected leaves. Please leave the need to be destroyed so that the fungus can’t spread to other rose plants

Question 13

What is malaria
How was it caused
What does it cause

Answer 13

Malaria is caused by a protest

Part of the malarias protests life-cycle takes place inside the mosquitoes. The mosquitoes actors vectors they pick up malarial protest when they feed on an infected animal

Every time a mosquito feed on another animal infected by inserting the protest into the animals blood vessels

Malaria causes repeating episodes of fever. It can be fatal

The spread of malaria can be reduced by stopping the Mosquitoes from breeding

People can be protected from mosquitoes using insecticides and mosquito nets

Question 14

What is salmonella
How can you get it
What are the symptoms

Answer 14

Salmonella is the type of bacteria that is causes Food poisoning

Infected people can suffer from fever, stomach cramps, vomiting and diarrhoea

This symptoms are caused by the toxins that the bacteria produces

Salmonella is caused by eating food that’s been contaminated with salmonella bacteria e.g. chicken or food that has been contaminated by being prepared in unhygienic conditions

Question 15

What is gonorrhoea
how was it caused
what does it cause

Answer 15

Gonorrhoea is an STD
STDs are passed on by sexual contact
Gonorrhoea is caused by bacteria
Personal gonorrhoea will get pain when they urinate. Another symptom. Is a thick yellow or green discharge from the vagina or the penis
It was originally treated with an antibiotic called penicillin but this has become trickier now because strains of the bacteria become resistant to it

Question 16

How can you reduce or prevent the spread of diseases

Answer 16

Being hygienic e.g. washing hands
Destroying Vectras e.g. getting rid of the organisms that spread disease
Isolating infected individuals
Vaccination

Question 17

What is the bodies defence system

Answer 17

The skin acts as a barrier to the pathogen. It also secretes antimicrobial substances which kill pathogens

Hair and mucus in your nose trap particles that could contain pathogens

The trachea and bronchi I secrete mucus to trap pathogens

The trachea and bronchi I aligned with cilia. These are hairlike structures which waft the mucus up the back of the throat work can be swallowed

The stomach produces hydrochloric acid which kills pathogens that make it that far from the mouth

Question 18

How does the immune system attack pathogens

Answer 18

White blood cells can engulf foreign cells and digest them . This is called phagocytosis

Every invading pathogens has a unique molecules on its surface called antigens. When some types of white blood cell come across a foreign antigen they will start to produce proteins called antibodies to log on to the invading cells so that they can be found and destroyed by other white blood cells. Antibodies produced on specific to that type of antigen. This means they won’t lock onto any others. Antibodies are then produced rapidly and carried around the body to find all the symbol of bacteria or virus. If the person is infected with the same pathogen again the white blood cells rapidly produce antibodies to kill it. The person is naturally immune to that pathogen and won’t get ill

Question 19

How does vaccination protect from future infections

Answer 19

Vaccinations involve injecting small amounts of dead or inactive pathogens. These carry antigens which cause your body to produce antibodies to attack them even though the pathogen is harmless. Once pathogen is of the same type appear after that the white blood cells can rapidly must produce antibodies to kill off the pathogen

Question 20

What are the disadvantages of vaccination

Answer 20

Vaccines don’t always work sometimes they don’t give you immunity

You can sometimes have a bad reaction to a vaccine e.g. swelling or maybe something more serious like a fever or seizures. However this is very rare

Question 21

What are the advantages of vaccination

Answer 21

Vaccines have helped control lots of communicable diseases that once common in the UK. Smallpox no longer occurs at all and polio infections have fallen by 99%

Big outbreaks of disease called epidemics can be prevented if a large percentage of the population is vaccinated. That way even the people who aren’t vaccinated or on likely to catch disease because there are fewer people able to pass it on

Question 22

How can bacteria become resistant to antibiotics

Answer 22

Bacteria can mutate. This causes them to be resistant to an antibiotic

If you have an infection some of the bacteria might be resistant to the antibiotics

This means that when you treat the infection only the non-resistant strains of bacteria will be killed

The individual resistant bacteria will survive and reproduce, and the population of the resistant strain will increase

This resistant strain could cause serious infection that can’t be treated by antibiotics

To slow down the rate of development of resistant strains is important for doctors to avoid over prescribing antibiotics so you won’t get them for sore throat only things more serious

It’s also important that you finished the whole force of antibiotics and don’t just stop when you feel better

Question 23

What are the three main stages of drug testing

Explain what they are

Answer 23

Preclinical testing-

Drugs are tested on human cells and tissues in the lab. However you can’t use human cells and tissues to test drugs that affect hold on multiple body systems e.g. testing a job for blood pressure must be done on an animal because it it has an intact circulatory system

Live animals-
the Next step in preclinical testing is to test the job on live animals. This is the test efficiency, to find out about is toxicity And how often should be given.

Some people think it’s called a test on animals but others believe is the safest way to make sure drivers and dangerous before giving it to humans

Clinical trials-

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 dose of the drug is given and this is gradually increased

If the results of the test on the healthy volunteers are good the drugs can be tested on people suffering from illness.

To test how well the drug works, patients are randomly put into two groups. One is given the new drug and the other is given a placebo. This is so the doctor can see the actual difference the drug makes. It allows for the placebo effect

Clinical trials are blind-the patient in the study doesn’t know whether they are getting the Jerge all the placebo. Double-blind trials is when neither the patient know the doctor knows until the results have been gathered. This is so the doctor is monitoring the patient and analysing the results on subconsciously influenced by their knowledge.

The results of drug testing and drug trials aren’t published until they’ve been through peer review to prevent falls claims