D. Electrons because isotopes deal with electrons.
Two reasons Eugleoids are considered to be animal-like is because they can move from one place to another, and are heterotrophic (consumes food made by other organisms) or >> reproduces by fission << could be another option.
It makes it own food that why its called an AUTOtroph
Photosynthesis is one of the main processes that is basically responsible for the function of all living things. Without it carbon would not be cycled, oxygen would not be made and plants would not be able to creat food for themselves and would have to rely on another source.
Yes, the planet obeys the Kepler's Second Law. It is because it moves at equal time of one month at the same distance.
