But /and /yet/still/only

After which of the following treatments (I - III) would an enzyme still be expected to have activity? I. Protease treatment. II. Heating almost to the point of denaturation. III. Freezing and then thawing once only.

Assertion : All food chains will come to stand still if bacteria disappear from earth. Reason : Bacteria are only associated with the soil fertility and hardly any role for food chains.

List any three reasons why you would think that you are sick and ought to see a doctor. If only one of these symptoms were present, would you still go to the doctor? Why or why not?

In a nucleus, the number of RNA nucleoside triphosphates is 10 times more than the number of DNA nucleoside triphosphates, still only DNA nucleotides are added during the DNA replication, and not the RNA nucleotides. Why?