lqc 4 exam qs

Question 1

A wound is an injury to living tissue. The healing of a wound involves an inflammatory phase. Explain the appearance of the wound in this phase.

Answer 1

red/swollen, because of increased blood flow to the area

Question 2

describe what is meant by a non specific response to infection

Answer 2

a response that is effective against a wide range of infectious agents, doesn’t involve recognition of infectious agent, doesn’t react to specific antigens

Question 3

Using the fluid mosaic model of cell membranes, explain how a macrophage carries out phagocytosis of bacteria.

Answer 3

membrane receptors interacts with bacteria, pseudopodia formed around the bacteria, membranes of pseudopodia fuse to form a vacuole, change in shape of membrane is due to fluidity of membrane, caused by movement of phospholipids

Question 4

explain how macrophages present antigens to T helper cells

Answer 4

macrophage binding to T helper cell, MHC on macrophage, CD4 receptor on T cell

Question 5

The human body responds to infection by viruses in a number of ways. The non-specific response involves interferon. Explain the importance of interferon in the body’s response to infection by viruses

Answer 5

prevents viruses attaching to uninfected host cells, by binding to receptors, therefore preventing viruses from entering cell so viruses can’t replicate and infect more cells