Answer:
A
Explanation:
Earth's orbit is not constant because it does not travel in a circle but more of an ellipses.
B. Mutations cause a person's body cells to divide uncontrollably. There isn't a signal for cells to stop dividing, so this can cause cancer because cancer cells won't stop dividing without this signal.
The continents that are now separated by the Atlantic Ocean once formed a single landmass.
All of our current continents were once connected as one single landmass named Pangea. Pangea broke apart into different continents. Fossils found in Africa have been found in South America, and etc.
The structure of DNA is double helix which looks like twisted ladder. The sides of the DNA molecule, the rails of the ladder are composed of alternate phosphate and sugar molecules.