Biology Exam

Question 1

1 The body’s main first line of defence against disease is
J the skin
K white blood cells
L ear wax, hairs in the nose and stomach acid
M sneezing

Answer 1

The skin

Question 2

2 Active immunisation involves
J Providing antitoxins to protect the body against invading bacteria.
K Stimulating the immune system to produce antibodies against an invading microbe.
L Actively immunising a large proportion of the population to stop an epidemic.
M Injecting immunoglobulins into the patients body.

Answer 2

K Stimulating the immune system to produce antibodies against an invading microbe.

Question 3

3 Passive immunisation involves
J administering prepared antibodies to induce temporary immunity.
K a vaccine that is administered orally.
L the body relying on actively acquired immunity to fight disease.
M vaccines that are composed of inactivated or killed viruses rather than live viruses.

Answer 3

J administering prepared antibodies to induce temporary immunity.

Question 4

4 Passive immunity cannot be acquired
J during breast feeding.
K through immunisation
L through the placenta
M through injections of killed bacteria.

Answer 4

M through injections of killed bacteria

Question 5

5 Vaccination programs have been introduced as an effective way of managing disease. How do vaccines function?
(A) Vaccines artificially produce immunity.
(B) Vaccines help the body synthesise antigens.
(C) Vaccines stimulate production of antibiotics.
(D) Vaccines suppress the production of T and B memory cells.

Answer 5

(A) Vaccines artificially produce immunity.

Question 6

6 A patient was prescribed a course of antibiotics for an infection of a cut. The instructions on the packet included the statement: ‘all tablets in the course must be taken as directed’. Why is this necessary?
(A) to ensure that the cut is healed
(B) to prevent infection by another pathogen
(C) to prevent the development of resistance to the drug
(D) to prevent the build-up of scar tissue over the wound

Answer 6

(C) to prevent the development of resistance to the drug

Question 7

7. Which of the following is NOT a method of transmission of an infectious disease?
   J Influenza from airborne particles
   K Gangrene from war wounds.
   L Rabies from an infected dog
   M Cancer from cigarette smoke

Answer 7

M Cancer from cigarette smoke

Question 8

Question 9
(a) What is an antibiotic?

Answer 8

Antibiotics work by blocking vital processes in bacteria, killing the bacteria or stopping them from multiplying. This helps the body’s natural immune system to fight the bacterial infection.

Question 9

Question 9
(b) Briefly outline how antibiotics are effective in controlling infectious diseases.

Answer 9

They kill the bacteria and prevent infections from spreading and doing further harm to the body. They help the body fight infection, assisting the immune system allowing the body to recover quicker.

Question 10

(a) Describe the structure of a virus

Answer 10

All viruses contain nucleic acid, either DNA or RNA (but not both), and a protein coat, which encases the nucleic acid. Some viruses are also enclosed by an envelope of fat and protein molecules.

Question 11

(b) Describe how a virus reproduces

Answer 11

Viruses attache to the host cell and injects its DNA. Using the host’s cellular metabolism, the viral DNA begins to replicate and form proteins. Then fully formed viruses assemble. These viruses break, or lyse, the cell and spread to other cells to continue the cycle.