communicable diseases

Question 1

bacteria

Answer 1

Bacteria are prokaryotic cells meaning that they have no membrane bound organelles and, as such, do not have a nucleus – their genetic information is stored in the form of a circular
strand of DNA
Bacteria do not require a host to survive whereas viruses are entirely dependent on their hosts and cannot survive without them
Bacteria have a cell membrane, cell wall and cytoplasm as well as other organelles such as ribosomes, plasmids, flagellum and pili

Question 2

viruses

Answer 2

viruses consist of just nucleic acid enclosed in a protein coat and
their genetic material can take the form of DNA or RNA
viruses possess no such structures.
Viruses are significantly smaller than bacteria

Question 3

TB

Answer 3

TB is caused by a bacteria which infects phagocytes in the lungs.
it causes damage to the leaves resulting in a mosaic virus pattern
the damage then prevents the plant from growing

Question 4

Meningitis bacterial disease

Answer 4

Meningitis can be caused by bacterial infection of the meninges (a set of protective membranes around the brain).

Question 5

HIV viral disease

Answer 5

HIV is transported around the blood until it attaches to a protein on the t-helper cells
AIDS is when the replicating virus in the helper t cells interfere with the normal functioning of the immune system

Question 6

Influenza viral disease

Answer 6

influenza whereby the virus infects the ciliated epithelial cells of the
gas exchange system. There are different strains of influenza

Question 7

Athlete’s foot

Answer 7

Athlete’s foot in humans which is
caused by a fungus and is spread by direct contact with the spores on the skin surface or other surface

Question 8

malaria

Answer 8

Malaria is an example of indirect transmission via vector in the form of a female Anopheles mosquito.

Question 9

Tobacco mosaic virus

Answer 9

Tobacco mosaic virus infects tobacco plants, a
major crop worldwide.

Question 10

blight and Black Sigatoka

Answer 10

Potatoes can be affected by blight which is caused by a fungus and
bananas can also be affected by fungus causing Black Sigatoka

Question 11

how does hot climate make transmission more likely?

Answer 11

Increased heat provides kinetic energy chemical reactions and reproduction

Question 12

How does social factors make transmission more likely?

Answer 12

in developing countries it could result in a
lack of food
poorer sanitation
overcrowded living quarters

Question 13

Direct transmission

Answer 13

Direct contact – touching kissing contact with cut skin
Inoculation -