Question

The biological outcomes of immune system recognition can include:

1) Migration of leukocytes into infected tissues

2) Clearance of a pathogen by an activated macrophage

3) Promotion of optimal antigen presentation

4) Induction of long-lived B and T cells

5) All of the answers are correct

The end results of signal transduction are varied but can include:

1) Induction of cell division

2) Cellular differentiation

3) Altered metabolism

4) Altered protein secretion patterns

5) All of the answers are correct

Answer 1

• The biological outcomes of immune system recognition can include all the outcomes given in options.
  • Migration of leukocytes into infected tissues particularly neutrophils.
  • Clearance of pathogens (bacteria and fungi) by macrophages; they, however, fail against protozoans.
  • Promotion of optimal antigen presentation is a key component of immune system. Antigen presentation for raising immune response is done by APCs (Antigen Presenting Cells) for both endogenous and exogenous antigens, and all nucleated cells of body for endogenous antigens.
  • Induction of long lived B cells i.e. plasma cells and T cells i.e. memory T-cells are formed during first encounter with a particular antigen. They come into action only during subsequent infection by the same antigen.
• The end results of signal transduction are varied but can include all the outcomes given in options.
  • based on the type of signal and cell, the outcome of a signal could be cellular division to cellular differentiation, also the rate or direction or fate of a metabolism (both catabolism and anabolism) can change (when signalled for the availability/ concentration of substrate and product). Different proteins are secreted for different functions in a cell or body at a time for e.g. HSPs, Nitrogen fixation proteins, etc.