problem 1:

a) How are two strands of a DNA molecule joined altogether?

b) What do you mean by the term junk DNA?

problem 2:

Answer the given problems by referring to the processes that you employed to isolate DNA from a plant tissue.

a) Having obtained a plant tissue ex: onion

• What was the first process that you followed?
• Illustrate the reason for that process?

b) Washing-up liquid is then employed in the isolation. Illustrate a reason for its use.

c) Salt (sodium chloride) is as well used in the isolation. Illustrate a reason for its use.

d)
• What do you mean by the term protease?
• Why is a protease essential when isolating DNA?

e) The final phase of the isolation includes the use of freezer-cold ethanol.

• describe how it is used.
• For what reason is it used?