Answer:
ATP is the universal energy carrier in cells.
The difference between analog and digital signals is that an analog signal is a continuous electrical message while digital is a series of values that represent information. Analog is conveyed by electrical current variations.
Polaris (aka the North Star) has a radius of around 22 million miles, which is about 50 times the size of our sun!
The correct option is A.
Succession refers to the process by which the structure of a particular biological community evolves over a period of time. There are primary and secondary succession. Primary succession usually occur in an area in which the soil is not capable of sustaining the growth of plants. The options B, C and D given in the questions are examples of primary succession.