Question 1:
a) How are two strands of a DNA molecule joined altogether?
b) What do you mean by the term junk DNA?
Question 2:
Answer the given questions by referring to the processes that you employed to isolate DNA from a plant tissue.
a) Having obtained a plant tissue example: 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.
• Explain how it is used.
• For what reason is it used?