The unwinding of DNA at the replication fork causes twisting and strain in the DNA ahead of the fork, which is relieved by an enzyme called .

Topoisomerase

Explanation:

Topoisomerase is an enzyme that is involved in the unwinding of Deoxyribonucleic acid (DNA).  They are involved in double stranded DNA and they help to relieve the making of supercoils.

Topoisomerase play an important role during DNA replication, as the prevent the the twisting of the DNA double helix ahead of the replication fork. In other words, they ensure that the DNA open up for unwinding without being tightly wound.

The correct answer is "topoisomerase".

Explanation:

Topoisomerase is an enzyme that is essential to perform DNA replication and transcription. Topoisomerase catalyzes the overwinding or underwinding of DNA, for which they are know as "the magicians of the DNA world" because they relieve the twisting that are formed in the DNA ahead of the fork during replication. Topoisomerase are needed because of the intertwined nature of its double-helical structure

try using substitution:

x + y - 6 = x - y. (i'm not giving you the exact answer). since 0 = x - y, then sub 0 in the equation with x - y. combine your like terms, and then use inverse operations, and you'll have your answer.

: -)

which

what is a measurement of the earth’s history divided into time periods?

> fossil record <

sedimentary rock

> geologic time scale <

radioactive elements