Which best describes why gel electrophoresis works?
a. dna with mutations cannot pass through the gel.
b. dna with a more negative charge moves more slowly.
c. smaller dna segments move more easily through the gel.
d. reverse transcriptase molecules have a negative charge.

Ans. (C). smaller DNA segments move more easily through the gel.

Gel electrophoresis is defined as a molecular biology technique, used for the separation of DNA molecules from a mixture. In this,  the agarose gel, placed in a buffer, is used through which, molecules of DNA get separated.

The gel electrophoresis equipment has two poles, positive pole and negative pole at the each end. When current is allowed to the system, DNA molecules (negatively charged) run on the gel (towards the positive charge) according to their shape and size.

The smaller DNA fragments move faster and more quickly than larger fragments, and bands of different DNA molecules are formed in the gel according to their size.

Thus, the correct answer is option (C).

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.