Question

Resistance of some animals to certain viral diseases is based on

A) lack of spikes for attachment.
B) phagocytosis of the virus by the host cell.
C) the presence of the viral envelope.
D) lack of specific receptors on the host cell

Answer 1

Animal resistance to certain viruses is largely due to the absence of specific receptors on their cells, which are needed for viruses to attach and infect them. If the cells lack these receptors, the virus cannot replicate within the host, providing resistance to the disease.

Step-by-step explanation:

The resistance of some animals to certain viral diseases is often because they lack specific receptors on their host cell. Viruses rely on these receptors to attach themselves to the host cells and initiate infection. For example, the influenza virus binds specifically through its glycoprotein adhesins to receptors on the respiratory system's cell membranes. If the host cells do not possess the receptors that a virus requires for attachment, the virus cannot enter the cells and replicate. This lack of receptor is a key aspect of the host range limitation for viruses. It's important to note that other defense mechanisms, such as the immune response and phagocytosis, also play critical roles in combating viral infections.