Answer:
C. top soil has more organic matter.
Explanation:
It's more fertile than subsoil, due to having more organic matter and because fertilizers are usually added to the topsoil only.
To bring oxygen in the body because it is a respiratory organ fish
DNA ligase is the enzyme that repair irregularities and breaks in the back bone of double stranded DNA. The enzyme function by sealing the repair in the DNA, it seals recombination fragments and it connects okazaki fragments during replication of DNA.
If a mutation reduce the amount of ligase, all the functions of the ligase enzyme listed above will be affected negatively.
