Question

Starting with an original cell that undergoes DNA replication followed by mitosis and cell division and gives rise to daughter cells. One of the daughter cells undergoes replication. What would be true for the DNA of second generation daughter cells?

• A. One of the cells will contain DNA consisting of one strand from the original cell
• B. One of the cells will contain DNA consisting of two strands from the original cell
• C. Both of the cells will contain DNA consisting of one strand from the original cell
• D. Both of the cells will contain DNA consisting of two strands from the original cell
• E. Neither of the cells will contain DNA consisting of strands from the original cell

Answer 1

The correct option is A One of the cells will contain DNA consisting of one strand from the original cell

DNA replication is a semi conservative process wherein each daughter cell have one original strand and one newly synthesized strand. Replication of original DNA molecule will produce two DNA molecules each carrying one original and one newly synthesized strand. Replication DNA of from first generation cell would make two DNA molecules; one daughter DNA molecule would have the original strand as a parental strand. So, one of the second generation daughter cell would get the DNA molecule having the original DNA strand while other would not get any original DNA strand. Thus, the correct answer is option A.