What are sulfa drugs and why are they not a product of biotechnology?

Why aren't the stains like crystal violet and safranin washed away with water during simple staining?

What feature of cell theory is best demonstrated in the image

What is the function of the somatic nervous system? connects the brain and the spinal cord to the rest of the body carry signals to the muscles and glands includes all nerves controlling the muscular system and external sensory receptors controls internal organs like the heart and bladder