Which statement best describes the central nervous system? a) it senses stimuli and carries out a reaction. b) it secretes hormones. c) it is made up of all nerve cells. d)it is made up of the brain and the spinal cord.

The correct answer is -

D) It is made up of the brain and the spinal cord.

Central nervous system (CNS) is a part of the nervous that is primarily composed of two sub parts, which are brain and spinal cord.

Spinal cord lies inferior to the brain and it links majority of the PNS (peripheral nervous system) to the brain. It also transmits sensory information from various parts of body to the brain.

On the other hand, brain intergrates the sensory information (received from various body parts that possess sensory receptors) , processes it, and produces appropriate response, which is carried by motor neurons to the respective parts.

Thus, option D) is the right answer.

ecological efficiency: % of usable energy transferred as

biomass from one trophic level to the next typical is 10% efficient (90% of

energy is lost),is diagramed as the pyramid of energy flow. then osprey eagle

are tertiary consumer and the shrimp are primary consumer, so to balance

mass of shrimp (1/0.1) / 0.1 = 100 kg