(i) Write the scientific name of the vector that is responsible for the spread of dengue.

(ii) Write any two precautions that must be taken to check the spread of this disease.

OR

(i) Write the causes of AIDS.

(ii) How does the transmission of the disease causing agent occur?

(i): Aedes aegypti is the primary vector that is responsible for the spread of dengue.

(ii): Precautions that must be taken to check the spread of the disease is:

_• Do not store water in empty containers, as mosquitos breed at stagnant water places.

_• Protect yourself from mosquito bites, use mosquito repellents.

_• Avoid densely populated residential areas

OR

(a): AIDS(Acquired Immune deficiency syndrome) is a syndrome caused by HIV virus, in this condition persons immune system becomes too weak to fight any kind of infection.

Causes of AIDS include: it is caused by Human immunodeficiency virus(HIV)

_• having unprotected sex

_• blood transfusion of the infected blood

_• sharing drug needles with someone who is infected by HIV

_• virus passing from an expectant mother to her baby.

(b): Transmission is the process by which a pathogen spreads from one host to another.

There are two different modes of transmission:

1. Direct Transmission: this occur when the pathogen is transmitted directly from infected person. E.g: person to person, spread by skin, spread through blood.

2. Indirect transmission: when the pathogens are not directly but through the vectors such as flies, mosquitoes, ticks, dogs, etc….E.g: airborne transmission, contaminated objects, transmission through animals.