Stem cells are what allow planaria to grow and regenerate as the stem cells can change into any of the cells that make up the planaria.
They are both are types of explanations.
The characteristic best distinguishes glycolysis and the Krebs cycle from the electron transport chain is the amount of ATP produced . In glycolysis net ATp production is 2 ATP and in 1 Kreb's cycle 38 ATP are produced. Hence option A is correct.
