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 human body has living cells that interact with other living cells (Food) and inorganic cells (Salt, Oxygen). It also has a lot of chemical reactions that simultaniously happen inside of it.
Inorganic systems usually do not interact with themselves, and the reactions are mostly exterior.
Answer:
D. The biosphere change the lithosphere
Explanation:
The red formed due to oxygen which is produced by plants in the process of photosynthesis. This oxygen then reacted with iron atom and formed oxidized iron layers of sedimentary rock. So here plants are responsible for the formation of these layers and we considered plants as part of biosphere so we can say that biosphere is responsible for the change of lithosphere.
Answer:
C. levels of specific hormones