Biology Unit 3 Questions Megathread

[Inside Out]

is a granulocyte a phagocyte

[Russ]

They're classes of cell, you can't make comparisons like that.
Some granulocytes are phagocytes.

[HERculina]

handy diagram in my textbook that is pretty clear with classifying leukocytes:

[Inside Out]

how do phagocytes recognise that a virus-infected cell is non-self?

[Drunk]

When a virus infects a cell, it leaves an antigen on the cell's surface that the T-cell can recognise as foreign.

[Inside Out]

so do phagocytes engulf any virus infected cells at all? or does is jst engulf bacteria and viruses that haven not infected the cell? SO what happens to the virus infected cell? does it travel to the lymph node and attach itself to a T helper cell? Im confused :S

[Kaille]

Just checking do the antibodies bind to the antigens on cells when they agglutinate pathogens?

[Christiano]

I came across an MC q in insight 2007 and it said ribosomes, mitochondria and chloroplasts are directly responsible for the assembly of proteins - what do chloroplasts have anything to do with it?

I picked ribosomes, mitochondria and the nucleus ..

[Kaille]

In cell mediated immunity, should i say that t helper cells recognise antigens on MHC 2 markers and then stimulate cytotoxic t cell? or am i better off saying that cytotoxic t cells recognise antigens on MHC 1 markers? Can i say that t helper cells recognise antigens on MHC 1 markers and then stimulate cytotoxtic t cells?

[jane1234]

In cell mediated immunity, should i say that t helper cells recognise antigens on MHC 2 markers and then stimulate cytotoxic t cell? or am i better off saying that cytotoxic t cells recognise antigens on MHC 1 markers? Can i say that t helper cells recognise antigens on MHC 1 markers and then stimulate cytotoxtic t cells?

Th cells recognise antigens on MHC II markers, Tc cells are stimulated by them and then bind to MHC I markers to release their cytotoxins in cells.
Pretty sure Th recognise MHC II, not MHC I...

[Kaille]

Thanks!!!

[Kaille]

If a T helper cell is involved in activating B cells to produce antibodies, is it cell mediated immunity or the humoral response?

[jane1234]

If a T helper cell is involved in activating B cells to produce antibodies, is it cell mediated immunity or the humoral response?

T helper activating B cells = cell mediated
B cell producing antibodies = humoral

[Kaille]

omgosh thanks so much !!

[Russ]

so do phagocytes engulf any virus infected cells at all? or does is jst engulf bacteria and viruses that haven not infected the cell? SO what happens to the virus infected cell? does it travel to the lymph node and attach itself to a T helper cell? Im confused :S

Phagocytes don't engulf the entire cell, it's too big.
The virus infected cell is recognised as such and destroyed by NK cells, granulocytes, Tc cells etc.