Why does neurones contain many mitochondria and many ribosomes?

Neurons depend on mitochondria. ATP generation by mitochondrial respiration in the brain consumes 20% of the body's oxygen although the brain is only 2% of the mass of the body (Attwell and Laughlin, 2001). ... Every part of the neuron requires ATP and therefore requires mitochondria to be present.The dendritic processes and spines of neurons are essentially expansions of cytoplasm containing most of the organelles found in the cell body. ... Rough endoplasmic reticulum and ribosomes are present in large but not small dendrites.

several tissues working together form an organ, and several organs together make up an organisms.

the group of cell that carries out special jobs are tissue.

the answer is d. none of the above