GCSE Biology Question Analysis Topic: Biology - Short Questions
Exam Questions:
1) How are 'sticky ends' formed on a DNA strand? Why are they so called?
2) A woman has certain queries as listed below, before starting with contraceptive pills. Answer them.
(a) What do contraceptive pills contain and how do they acts as contraceptive?
(b) What schedule should be followed for taking these pills?
Answers:
For GCSE Biology, you should know:
1) The restriction enzymes produce sticky ends. The DNA strand is cut by the restriction enzymes between the same two bases on the opposing strands, but a only little bit away from the palindromic sequences' centres.
The ends are now left with single-stranded sections. Each strand has stretches that hang are known as "sticky ends."
Because they form hydrogen bonds with their complementary cut counterparts, such things are known as sticky ends. The DNA ligase enzyme can serve its purpose more effectively because of how sticky the ends are.
2) (a) Such pills contain progesterone, estrogen or a combination of both.
Contraceptives work by namely three ways:
1) Inhibiting ovulation
2) Inhibiting implantation
3) Changing the cervical mucus' quality in order to prevent the entry of sperm.
(b)
The pills ought to be taken every day for 21 days, most preferably within the menstrual cycle's first five days.
Work hard for your GCSE Biology examination!
End of analysis. Great!
