A. external
These types of signals are observed when there is a cut on the body. The epidermal cells lose contact with one another and divide faster until they are in contact once again. After they come into contact, division slows down again.
The best and most correct answer among the choices provided by the question is the fourth choice. The organisms survived in high and low salinities because of the t<span>emperature fluctuations can cause changes in the salinity levels of the water. </span>I hope my answer has come to your help. God bless and have a nice day ahead!
Answer:
I would believe the mesosphere would be the most difficult layer to breathe. Troposphere is where we are, ov we can breathe here, stratosphere would be hard to breath in as well
