A gel was loaded and allowed to run. The arrows indicate the final position of three samples. Which comment is true?

Sample 1 has the smallest molecular fragments Sample 3 has the smallest molecular fragments. Sample two has the lowest overall negative charge. Sample 1 has the most positive charge.

An agarose gel is loaded and allowed to run. It is clear that each sample travels at different speeds along the gel. Which one statement best describes why?

The speed fo the samples is directly related to the strength of the electrical field. The speed of each sample depends on the molecular mass of the samples. The samples travel at different speeds due to the force of the electric charge applied to the gel. The solution which the fragments are dissolved in helps pull the samples along at different speeds.

Consider the picture on the right. It shows a small piece of DNA. Which one of the follwoing statements is most appropriate?

Strong hydrogen bonding connects the sugar to the phosphate to form a single strand. Weak hydrogen bonding connects the sugar to the phosphate to form a single strand. Strong covalent bonds attach the two strands together. Weak hydrogen bonds attach the two strands together.

Consider the two DNA fragments shown on the right. Which comment is true?

The strands in fragment A will separate at a higher temperature than B. Fragment A has the highest molecular mass. The strands in fragment A will separate at a lower temperature than the strands in B

Solution