All viruses have is a protein coat and a core of genetic material, either RNA or DNA. Unlike bacteria, viruses can't survive without a host. They can only reproduce by attaching themselves to cells. Unlike bacteria, most viruses do cause disease, and they're quite specific about the cells they attack.
Answer:
The culture might not be stained properly or the culture might be too old.
Explanation:
Gram staining is done to differentiate between gram-positive and gram-negative bacteria according to the difference in their cell wall. In gram staining, the gram-positive bacteria appears violet and gram-negative bacteria appear pink in color.
Therefore if a pure culture contains have both red and purple cocci that it can be concluded that the gram stating was not done properly like too much destaining was done or too much safranin was used or maybe the culture is too old so that cell wall of some bacteria degrades.
Answer:
2 membrane layers cover up the nucleus
<span>Stem cells. There are two types of stem cells: adult stem cells - these are unspecialised cells that can develop into many (but not all) types of cells. Embryonic stem cells - these are unspecialised cells that can develop into any type of cell. And that's all! ;)
Hope this is useful !!!^_~!!!</span>
You need to put up a picture
