Question

When Okazaki incubated bacteria in [3H]-thymidine for ______ and immediately killed them, the radiolabel was found as part of ________; if the cells were incubated in labeled DNA precursor for _____, most of the incorporated radioactivity became part of ________.

a. a few seconds, a large DNA molecule, 1 to 2 minutes, small DNA fragments
b. a few seconds, small DNA fragments, 1 to 2 minutes, small DNA fragments
c. a few seconds, small DNA fragments, 1 to 2 minutes, a large DNA molecule
d. 1 to 2 minutes, small DNA fragments, 2 hours, a large DNA molecule
e. 1 to 2 minutes, a large DNA molecule, a few seconds, a large DNA molecule

Answer 1

The correct answer to the question is option c: a few seconds, small DNA fragments, 1 to 2 minutes, a large DNA molecule.' This reflects the process of DNA replication where short Okazaki fragments are initially synthesized and then joined to form longer DNA strands. The correct option is c. a few seconds, small DNA fragments, 1 to 2 minutes, a large DNA molecule

Step-by-step explanation:

When Okazaki incubated bacteria in 3H-thymidine for a few seconds and immediately killed them, the radiolabel was found as part of small DNA fragments; if the cells were incubated in labeled DNA precursor for 1 to 2 minutes, most of the incorporated radioactivity became part of a large DNA molecule.

The correct answer to the fill-in-the-blank question is therefore: 'a few seconds, small DNA fragments, 1 to 2 minutes, a large DNA molecule,' which corresponds to option c.

The incorporation of labeled thymidine into DNA provides insight into the process of DNA replication. Initial brief exposure results in labeled Okazaki fragments, which are later joined to form longer DNA strands during replication. The correct option is c. a few seconds, small DNA fragments, 1 to 2 minutes, a large DNA molecule