Answer: A. (3) mechanical energy
B. (3) conservation of energy
Step-by-step explanation:
A. Mechanical energy
A mechanical energy can be define as the combination of the potential energy and kinetic energy in an object that is utilized to do work. In the given situation, the chemical energy from plankton is converted into mechanical energy in the fish. As the plankton being the source of food, is a source of chemical energy, the chemical energy in the plankton will be converted into mechanical energy in the fish which will be used by the fish to swim.
B. Conservation of energy
According to law of conservation of energy in universe, the energy changes it's forms but it can neither be created nor be destroyed. In the given situation, the energy is released when the bacteria break down the fish bodies, which is later on absorbed by the other organisms in the ecosystem. This way the flow of energy is indicating towards the conservation of energy. As the energy is being transferred from one organism to another. Hence, the energy is changing it's form from one to another.