BIOLOGY: Health, disease & development of medicine

Question 1

Define Health.

Answer 1

A state of complete physical, social, and mental well-being not merely in the absence of disease or infirmity

Question 2

What’s a communicable disease?

Answer 2

A disease that can be spread between individuals

Question 3

What’s a non-communicable disease?

Answer 3

A disease that can’t be transmitted between individuals

Question 4

Explain why the presence of one disease can lead to a higher susceptibility to other diseases.

Answer 4

Your body/immune system may become weakened by the disease, so it’s less able to fight off others

Question 5

What’s a pathogen?

Answer 5

An organism (such as viruses, protists, bacteria and fungi) that cause communicable diseases

Question 6

What are the two pathways that a virus can take during the life cycle?

Answer 6

Lytic, Lysogenic

Question 7

Describe the Lysogenic pathway.

Answer 7

1) The injected genetic material is incorporated into the genome (DNA) of the host cell
2) Viral genetic material gets replicated along with the host DNA every time the host cell divides - but, the virus is dormant (inactive) and no new viruses are made
3) Eventually, a trigger (e.g. presence of a chemical) causes the viral genetic material to leave the genome and enter the lytic pathway

Question 8

Describe the Lytic pathway.

Answer 8

1) Virus attaches to a specific host cell host cell and injects its genetic material
2) Virus uses enzymes and proteins in the host cell to replicate its genetic material and produce the components of new viruses
3) The viral components assemble
4) The host cell splits open, releasing the new viruses, which infect more cells

Question 9

What is the main symptom of Malaria?

Answer 9

Damage to red blood cells and (in extreme cases) the liver

Question 10

How are Stomach Ulcers transmitted?

Answer 10

Through Oral Transmission e.g. contaminated water/food

Question 11

How do you prevent/reduce transmission of Stomach ulcers?

Answer 11

Clean water and hygienic living conditions

Question 12

How do you prevent/reduce transmission of Ebola?

Answer 12

Isolate individuals, sterilise any possible virus present areas

Question 13

What is the main symptom of Ebola?

Answer 13

Haemorrhagic fever (bleeding)

Question 14

Describe Chlamydia.

Answer 14

Caused by a bacteria
Can only reproduce inside the host cell
Can lead to infertility
Prevented thought usage of condoms, avoiding sexual contact, screenings

Question 15

Describe HIV

Answer 15

Virus
Damages white blood cells - leads to AIDS
AIDS is cause by immune system deteriorative and eventually failing
Prevented by use of condoms, trying to not share needles, medication, screenings, proper treatment

Question 16

What are cell walls made of?

Answer 16

Cellulose

Question 17

What are 2 chemical defences against pathogens and pests used in plants?

Answer 17

Antiseptics kill bacterial and fungal pathogens
Plants also produce chemicals to deter pests from feeding on their leaves (e.g. Aspirin found in willow tree bark/leaves)

Question 18

How does the immune system attack pathogens?

Answer 18

When white blood cells (B-lymphocytes), come across an antigen on a pathogen, they produce proteins called antibodies.
The antibodies bind to the new invading pathogen, so it can be found
The antibodies are then produced rapidly and flow around the body to find all similar pathogens.

Question 19

How are Monoclonal antibodies made?

Answer 19

Inject mouse with chosen antigen
Extract B-lymphocyte white blood cell and fuse with a myeloma (tumour) cell to form a hybridoma
Hybridoma can then divide rapidly and these clones produce lots of monoclonal antibodies