Correct Answer: Option 1 gel electrophoresis

Gel electrophoresis is a technique used for the separation of deoxyribonucleic acid (DNA), ribonucleic acid (RNA), or protein molecules using an electric current applied to a gel matrix.[1] DNA Gel electrophoresis is generally only used after amplification of DNA via PCR. It is usually performed for analytical purposes, but may be used as a preparative technique prior to use of other methods such as mass spectrometry, RFLP, PCR, cloning, DNA sequencing, or Southern blotting for further characterization.

DNA replication and protein synthesis are natural occurrences in our body that can be simulated in laboratory conditions. However, the process illustrated is electrophoresis. Thus, options 2 and 3 are incorrect.

On the other hand, genetic recombination is also a laboratory technique but this particular example is not genetic recombination itself. Hence, option 4 is incorrect.

This technique has lots of applications. Generally speaking you can analyze DNA fragments that result from an enzyme digestion of a larger piece of DNA to visualize the fragments and determine the sizes of the fragments. In addition to its usefulness in research techniques, agarose gel electrophoresis is a common forensic technique and is used in DNA fingerprinting.

Correct Answer: Option 4 Both the yellow food-coloring molecules and the blue food-coloring molecules are small

The evidence for this statement is the change of color in and out of the dialysis membrane. The dialysis membrane is a semipermeable membrane which only allows certain particles.

If only the yellow-coloring molecules are small, then only the dialysis bag should be colored green. The blue-coloring molecules should not be able to travel out of the dialysis membrane. Hence, option 1 is incorrect.