Because they are the essential micronutrients for the different metabolites of living organisms?
Given:
The solution decreased by 
ounces every hour for 5 hours.
Remaining solution at the end of the experiment = 
ounces.
To find:
The initial amount of solution.
Solution:
Let the initial amount of the solution be x.
The solution decreased by ounces every hour for 5 hours.
Total decreased amount 
Initial amount = Remining amount + Decreased amount of solution.
Therefore, the initial amount of solution is 18 ounces.
Answer:two types of joints are fibrous or cartilaginous.
Explanation: An immovable joint connects the ends of the bones by a tough fibrous tissue.
Answer:
1. Signaling molecule
2. Signaling receptors
Explanation:
Hormones, growth factors, neurotransmitters, etc. serve the function of signaling molecules for cells. These molecules are released by one cell and bind to the receptors present on/in the target cells to elicit the desired response. Thereby, the signaling molecules serve in cell-cell communication.
For example, insulin hormone synthesized and released from beta cells of pancreas binds to its cell surface receptors present on the surfaces of liver cells and muscle cells to stimulate the uptake of the glucose from the blood.
Likewise, neurotransmitters released from the presynaptic neuron bind to receptors present on the membrane of postsynaptic neuron and serve to carry the nerve impulse to the postsynaptic neuron.
Answer: A,B and C
Explanation
