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.
Using a microscope
Explanation:
A microscope is a scientific device used for magnifying and studying very tiny features.
It was invented by Anton Von Leeuwenhoek in the 17th century.
- A unicellular organism is an organism made up of a single cell.
- A multi-cellular organism is made up of several cells.
- A cell is a very small microscopic structure.
- It is usually described as the fundamental unit of life.
- Due to its small size, the naked eyes cannot see it
- The invention of the microscope opened up the world of cells.
- Since they have been around for a long time, distinction of cells would have been made possible at those times using a microscope.
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Answer:
a. methylation at lysine 9 or 27 of histone H3.
Explanation:
Methylation causes the switching off of genes using steric hinderance to prevent access to DNA.
