There are special proteins that help to open up the DNA double helix in front of the replication fork. These proteins are:
Correct answer: B. DNA topoisomerase I
- A. DNA ligase
- B. DNA topoisomerase I
- C. DNA gyrase
- D. DNA polymerase I
Explanation
DNA is a double helical molecule and it opens to form a replication fork or its replication. The two strands of DNA are joined with the help of H-H-bonds between the strands. Topoisomerases are specialized to cause nicks or breaks in the double helix and help separate the DNA strands. Helicase unwinds the DNA helix from hat ck caused by the topoisomerase and this sepseparatese two strands. DNA gyrase introduces negative supercoils in the DNA strands of prokaryotes. DNA polymerase adds nucleotides units to the 3' end of a DNA chain. DNA ligase joins the ends of DNA.
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About Chromosomes
Chromosomes are DNA-protein structures that carry genes and become visible during cell division. Coverage includes chromatin, centromeres, sister chromatids, homologous chromosomes, chromosome number, and the distinction between diploid and haploid cells, with links to DNA replication, mitosis and meiosis.
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