A shell is considered as biotic (living) because it is a hard, rigid covering of many animals such as snail, sepia, pila, turtles, sea urchins. A shell is protective outer layer of these soft bodied animals.
Chemical messengers and the Electrical signals are the two main methods by which cells communicate with each other to coordinate their functions and metabolic activities.
According to biologist, A cell communicates through chemical messengers, by sending the chemical signals to other cells and also receive that signal from another cell. Similarly, Electrical signals or impulses also work in the same way.
Therefore, body contains many types of lipids which works as a chemical messengers also electical signal or impulses can easily travel throught these lipids. Cell uses these chemical messengers and electrical impulses to communicate with other cell. Although, In order to trigger a response, these signals are transmitted across the cell membrane of the cell.
Learn more about cell communication here
brainly.com/question/18223077
#SPJ4
Are you from USA or not or India
The fertilizers used by farmers can have negative effects on aquatic ecosystems because there is every possibility that the runoffs from the fields can create an algal bloom in the nearby water body. This algal bloom can have a very negative effect on the living organisms of the aquatic body. I hope it helps.
Answer:
Evolution is a major force in shaping modern classification methods.
Hope it helped...........
