Naked Science Forum

Life Sciences => Cells, Microbes & Viruses => Topic started by: Seany on 05/01/2009 23:16:07

Title: Viruses and Bacteria.. What's the line between living and non-living?
Post by: Seany on 05/01/2009 23:16:07
I understand that bacteria has a nucleus, whilst a virus doesn't.. But viruses still multiply themselves and seems to have a want to live. Surely that makes  them a living thing?
Title: Viruses and Bacteria.. What's the line between living and non-living?
Post by: Chemistry4me on 05/01/2009 23:46:30
We were taught that all living things could do MRS.(C).GREN which stands for movement, respiration, sense, circulation (although that one is a bit dodgy), growth, reproduce, excrete, and nutrition (or something along those lines). I'm fairly sure that viruses can only carry out two of those functions, if my memory is correct. [::)]
Title: Viruses and Bacteria.. What's the line between living and non-living?
Post by: Seany on 06/01/2009 12:32:41
I do see your point.
Viruses

Move -- yes

Respire? -- (No. Viruses do not have the ability to respire on their own. They need to use the mitochondria of their host cells in order to use the process of respiration of the cell they have invaded. So, in other words,you could say that viruses "borrow" the respiratory ability of a cell, and that can be aerobic or anerobic, with or without oxygen.)

Sense -- no

Circulation -- no

Growth -- yes

Reproduce -- yes? multiplying in a way..

Excrete -- No idea..

Nutrition -- Surely they eat on something??

I'm still not sure whether MRS GREN has to agree for it to be living..! It's very vague!