The epithelial tissues are the thin tissues that covers all the parts of the body. These covers all the exposed surfaces of the body. These covers the dermal tissues, inner lining of the mouth, secretary glands, lining of hollow regions of the organs like eyes, ears, heart, lungs and the urogenital tract as well as the ventricular system of the spinal cord and the brain. Skin is the example of epithelial tissues it covers the inner dermal layers of the skin. It provides protection against the injuries and entry of the pathogens.
The answer is nucleic acid. Every nucleic acid is composed by a base, a sugar and a phosphate group. And they can form DNA or RNA by combining together.
An allele is one of a pair of genes that appear in a particular location on a particular chromosome and control the same characteristic, such as blood type or color blindness.
When the bacteria took pink color (safranine), it means they are gram-negative bacteria. Gram-negative bacteria have thick cell walls it does not take crystal violet stain as its cell wall is thicked. It take-up counterstain safranine and seen pink in the microscope.
