Answer:
Dry air is a mechanical mixture of nitrogen, oxygen, argon and several other gases in minor amounts.
Explanation:
Earth is a planet, Zero planets on earth
I believe you meant to say is this mistake called a base pair and if that is your question then no. it would be called Mutation. But you can double check that answer.
Answer:
Topoisomerase
Explanation:
Topoisomerases are enzymes that produce changes in the topology of the DNA during replication, transcription, traduction, or reparation processes. They can cut one or both strands and in order to relieve torsional stresses in the supercoiled structure of DNA. With this, they help to maintain the chromosome's integrity. There are two types of topoisomerases: topoisomerase I (it cuts only one strand of DNA) and topoisomerase II (it is able to cut both strands of DNA).
