Staying healthy

Question 1

What are non-infectious diseases caused by

Answer 1

Poor diet
Organ malfunction
Genetic inheritance

Question 2

Cancer is caused by mutations. What are benign and malignant tumours

Answer 2

Benign tumours don’t spread and are not cancerous

Malignant tumours can spread to other parts of the body

Question 3

Pathogens are disease causing microorganisms

What are the different types

Answer 3

Fungus
Bacteria
Virus
Protozoa

Question 4

Malaria is caused by a protozoan which is a parasite

What is the host and vector

Answer 4

The host is the human

The vector is the mosquito

Question 5

How can you prevent malaria

Answer 5

Mosquito nets
Insect repellants

Draining stagnant water or using oil

Question 6

What are the body’s defences against pathogens

Answer 6

The skin
Respiratory system-lined with cilia and mucus
Stomach- hydrochloric acid
Blood- clots to prevent pathogens entering

Question 7

How are symptoms of a disease caused

Answer 7

The pathogen in the body damages cells and produces toxins before the white blood cells can destroy them

Question 8

How do phagocytes work

White blood cell

Answer 8

Searches in bloodstream for pathogen

Engulfs and digests

(Pus is mainly white blood cells full of digested microorganisms)

Question 9

How do lymphocytes work

White blood cell

Answer 9

Recognise antigens (molecular markers) on surface of pathogen

Produces antibodies that lock onto these antigens and kills pathogen

Question 10

What is active immunity

Answer 10

Blood cells are sensitised to particular pathogen and can produce antibodies quicker if it is detected again

Can be achieved by vaccination (immunisation)

Question 11

What is passive immunity and the disadvantage

Answer 11

Given antibodies artificially

Not long term however because the white blood cells did not produce the antibody themselves

Question 12

How does immunisation (gained by vaccination) work

Answer 12

Weakened or dead strain of pathogen is injected. It cannot multiply but antigen molecules remain intact

Triggers white blood cells to produce specific antibodies
white blood cells (memory cells) remain sensitised so antibodies can be produced again quickly if same pathogen is detected

Question 13

Give some benefits and risks of immunisation

Answer 13

Protects from diseases and can even make it die out completely

Individuals could be allergic

Question 14

How can diseases caused by bacteria or fungi be treated

Answer 14

With antibiotics

Question 15

Negatives of antibiotics

Answer 15

Some bacteria can be naturally resistant to particular antibiotics

If too many are taken all bacteria in the population will be killed except resistant ones, that will spread. The antibiotic becomes useless

MRSA is resistant to most antibiotics

Question 16

How can a new drug be tested

Without using volunteers

Answer 16

Computer models
Animals
Human tissue-grown in lab

Question 17

In testing, what is a placebo

Answer 17

An inactive pill (thought to work)

The effects are compared to new drug

Question 18

What is a blind trial

Answer 18

The volunteers don’t know whether it is placebo or new drug

Eliminates psychological factors and gives fair comparison

Question 19

What is a double blind trial

Answer 19

Volunteers and doctors don’t know which pill has been given

Eliminates bias and influence

Question 20

How is malaria caused

Answer 20

Malaria parasites are sucked from human blood stream by mosquitoes (vector)
Parasites mate inside the mosquito, and move from the gut into the salivary glands
When the mosquito bites another person the malaria parasites are passed on into the bloodstream
They then go to human liver where they mature and reproduce then migrate to blood, replicating in red blood cells, bursting them open
This damage leads to malaria fever and even death

Question 21

Will antibodies made to react to tetanus have any effect on cholera?

Answer 21

No

Every pathogen has unique antigens. White blood cells make antigens specifically for a particular antigen

Question 22

Infectious diseases are caused by what

Answer 22

microorganisms

They attack and invade the body and are spread through unhygienic conditions or contact with infected person