Why is heartwood darker in color than sapwood?
a. heartwood is closer to the center of the stem; sapwood is away from the center of the stem
b. heartwood does not conduct water; sapwood is active in fluid transport
c. heartwood contains xylem tissue; sapwood contains phloem tissue

A. Heartwood is closer to the center of the stem; sapwood is away from the center of the stem

Explanation:

In woody plants it is possible to see the heartwood, which is formed by pots that do not have the capacity to transport any type of sap, but have a supporting function. It is also possible that we can see the sapwood, which is formed by conductive vessels of raw sap that leaves the roots towards the plants.

The heartwood is located in the innermost regions of the trunk, almost in the center of the stem, which allows this structure to have a darker color. On the other hand, the sapwood is located in more external regions and far from the center of the stem, which gives a lighter color.

cellular respiration oxidizes food into energy in the form of atps.

glycolysis (6 c hexose) > 2x atps are used > 6c hexose biphosphate > 2 x 3c triphosphate >

2 x 3c pyruvate (2x nadh produced from nad) and (4x atp produced)

pyruvate actively pumped mitochondrial matrix.