4. If both strands of a DNA molecule were labeled with radioactive atoms, and if

Question

4. If both strands of a DNA molecule were labeled with radioactive atoms, and if the DNA replicated during the formation of new cells, each of the two new cells would have exactly half the radiation of the original cell. Explain this observation? Only one on the two antiparallel strands for each gene contains information and is therefore transcribed. Why then is DNA double stranded? How does the RNA polymerase enzyme responsible for transcription know which of the two DNA strands to transcribe? 5.

Explanation / Answer

4. As replication of DNA is semiconservative.

Old strands open and new complementary strand is synthesised in front of it. So, if the old strand is radioactive then new strand synthesised from it will pass into two new cells. These new cells will have exactly half of the DNA as the original cell which was radioactive.

This happens only because reolreplica of DNA is semiconservative.

5. DNA is double stranded because it provides stability to the structure of DNA. It has two strands one is template and other is a non-template strand. These two strands are antiparallel and complementary to each other which are held together by hydrogen bonds.

There are signal sequences which are also known as promoter. They help RNA polymerase to initiate the transcription.

Related Questions

Navigate

• Browse (All)
• Browse 4
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.