Question

Nucleotides can be radiolabeled before they are incorporated into newly forming DNA and can be assayed to track their incorporation. In a pulse–chase experiment, a student–faculty research team introduced labeled thymine (T) nucleotides into a culture of dividing human cells. After a short time, they added large amounts of unlabeled T nucleotides. In which cell cycle phase would the labeled T nucleotides become incorporated into the DNA?

Answer 1

Answer:

In the interphase (taking into account that cell cycle is divided into two parts), t nucleotides become incorporated into the DNA

Explanation:

Answer 2

Answer:

The S phase

Explanation:

The cell cycle is divided into two major phases:

• The interphase
• The m Phase

The interphase is further sub-divided into 4 phases:

• The G0 phase: a dormant phase
• The G1 phase: cell growth and development phase
• The S phase: DNA synthesis/replication and centrosome duplication phase
• The G2 phase: protein synthesis phase

The labeled T nucleotides will become incorporated into the cell's DNA during the DNA synthesis/replication phase of the cell cycle. At this phases, the double helix DNA unzips and each strand serves as a template for the synthesis of new strands. Replication fork forms and nucleotides are added to the growing chain of newly synthesized strands.

The correct answer is S phase.