In what ways do living things depend up on each other?

The following hormone had their receptors in the cell membrane except a-insulin b-tsh c-gh d- cortisol

Will someone me with this.. specialized cells which perform a particular function form: tissues organs or organism

Ascience research group is testing a new type of plant food. one trial is conducted in a controlled experiment. the data from the trial show that the plant that received the new food grew faster than the control plant. the group announces that the new plant food makes plants grow faster. what is the main weakness in this scientific claim?