Which of the following is an example of physical weathering?
a. ice forming in cracks of rocks
b. acid rain falling on sidewalks
c. waves washing over rocks on the beach
d. water washing away soil in an area used by off-road vehicles

The correct answer is option a. "ice forming in cracks of rocks".

Explanation:

Physical weathering is a geological process that results in rocks breaking apart, but with a physical force that does not change its composition. Ice forming in cracks of rocks is an example of physical weathering known as Ice wedging. It results from water seeping down into the cracks of rocks, and when the temperature drops and water freezes, the water cracks the rocks as it expands when it becomes ice.

the dna molecules have a negative charge because of the phosphate groups in their sugar-phosphate backbone, so they start moving through the matrix of the gel towards the positive pole. power is turned on and dna fragments migrate through gel (towards the positive electrode).

explanation: