Which of the following characteristics of the Sun help life to exist on Earth? 1. The Sun’s gravity keeps the Earth in a consistent orbit.
2. The Sun’s radiation provides heat to the Earth.
3. The Sun’s light shines on half of the Earth at a time.
4. The Sun’s solar flares and storms shower the Earth with additional radiation.
5. The Sun’s spots cause cooler areas on the Sun’s surface.
6. The Sun’s position in relation to the Earth and Moon causes eclipses.

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."

this protocol provides a detailed procedure for agarose-based ip to purify and enrich the protein of interest.

stimulus is a change in the environment that causes an organism to react. the response is the reaction to the stimulus. some examples of stimuli for zebras are drought, to many predators, and bad feeding grounds such as dead grass or plants. zebras respond to stimuli just like all other living organisms