Can yall help me I'm confused on this

The organelle pictured is found in cells of and is theorized to have once been an independent organism.

In many humans, exposing the skin to sunlight over prolonged periods of time results in the production of more pigment by the skin cells (tanning). this change in skin color provides evidence that -

The starting materials in a nuclear change have a total mass of 2.3465 x 10-27 kg. after the change, the resulting materials have a mass of 2.3148 x 10-27 kg. how much energy was released during the change? 2.85 x 10-12 2.08 * 10-10 j 0 211 * 10-10 j 8.56 * 10-43