Because for the strands to form a double helix the base pairs have to match perfectly (adenine with thymine and cytosine with guanine) in DNA , and if a strand of RNA is paired with a split strand of DNA it goes adenine with uracil and cytosine with guanine (uracil replaces thymine)
Rover (or sometimes planetary rover) is a space exploration vehicle designed to move across the surface of a planet or other celestial body. Some rovers have been designed to transport members of a human spaceflight crew; others have been partially or fully autonomous robots. Rovers usually arrive at the planetary surface on a lander-style spacecraft.[1] Rovers are created to land on another planet, besides Earth, to find out information and to take samples. They can collect dust, rocks, and even take pictures. They are very useful for exploring the universe.
