Blood vessels expand during hot weather and retract/ tighten in cold weather
Answer:
Purple, spherical-shaped organisms arranged in chain like formations.
Explanation:
Bacteria are the microscopic organisms and included in the prokaryotes as they do not have nucleus. Two main types of bacteria are gram positive bacteria and gram negative bacteria.
The gram positive bacteria has thick cell wall peptidoglycan cell layer and can uptake the crystal voilet stain. These bacteria seems purple under the microscope due to the uptake of stain. The bacteria Streptococcus pyogenes are spherical in shape and occurs in the cluster of chain.
Thus, the correct answer is option (d).
Answer:
The increased temperature in this layer is due mainly to UV absorption by various chemical species, including ozone and molecular oxygen present in the stratosphere. Maximum heating takes place in the upper part of the stratosphere. Because of the stable air, pollutant mixing is suppressed within this layer.
