<h2>Gram staining is a technique used to differentiate between Gram-positive and Gram-negative bacteria.</h2>
Explanation:
Gram stain color the bacteria either red or violet depending on whether they are Gram positive or Gram negative. Gram positive bacteria have thick cell wall containing peptidoglycan compared to Gram negative bacteria which have thin cell wall. Due to this Gram positive bacteria stains purple by crystal violet. So, slide containing <em>S. pyogenes</em> with purple violet indicates that it is a Gram positive bacteria.
When your body gets overheated. This is a negative feedback loop. The arteries/veins will dilate letting more blood pass through. Your face tends to get red because there is more blood flow towards the surface in an effort to cool off. This is also why you sweat.