Exams

The statements true about viruses are :

1. The capsid enters the host cell if the virus is enveloped.

2. Enveloped viruses bud from the host cell. 

3. HIV contains reverse transcriptase.

4. A retrovirus contains RNA.

Heat energy can be transferred by three major methods. They are 

1. Conduction,

2. Convection and

3. Radiation.

Conduction is the movement of heat through a substance by the collision of molecules

Convection occurs when particles with a lot of heat energy in a liquid or gas move and take the place of particles with less heat energy.

Radiation is the transfer of energy by means of photons in electromagnetic waves governed by the same laws. It occurs through a vacuum or any transparent medium.

Emphysema is a condition that involves damage to the walls of the air sacs (alveoli) of the lung i.e, primarily causes shortness of breath due to over-inflation of the alveoli.

First, emphysema causes holes to gradually form inside the lungs' air sacs, thereby weakening their internal structure and inhibiting the exchange of oxygen and carbon dioxide.