The four bases in DNA are: adenine, thymine, cytosine, guanine.
In RNA, thymine gets replaced by uracil.
Purine is only a name for the two bases guanine and adenine.
It is called PANGEA THE SUPERCONTINENT
Answer: 
Explanation: Photosynthesis is a phenomenon in which green plants containing chlorophyll use sunlight as a source of energy to convert carbon dioxide and water to form glucose and oxygen.
Photosynthesis is the process used by plants, algae and certain bacteria to convert energy from sunlight and turn it into chemical energy in the form of glucose which is used a s a source of energy by many organisms.
The balanced chemical equation for photosynthesis is written as :

Answer:
Surface tension depends mainly upon the forces of attraction between the particles within the given liquid and also upon the gas, solid, or liquid in contact with it. The molecules in a drop of water, for example, attract each other weakly.
Example:
a glass of water is sitting on a table put a paper clip in it. it stays floating on the top.
Water striders can walk on water because of the surface tension of water.
Answer:
Due to there being more kelp, more crabs will survive and this will increase the crab population.
Explanation: