Nucleotides can be radiolabeled before they are incorporated into newly synthesized DNA and, therefore, can be assayed to track
their incorporation. In a set of experiments, a student-faculty research team used labeled T nucleotides and introduced these into a culture of dividing human cells at specific times. Use the following information to answer the question below. The research team used their experiments to study the incorporation of labeled nucleotides into a culture of lymphocytes and found that the lymphocytes incorporated the labeled nucleotide at a significantly higher level after a pathogen was introduced into the culture. They concluded that __________. a. their tissue culture methods needed to be relearned
b. infection causes lymphocyte cultures to skip some parts of the cell cycle
c. infection causes cell cultures in general to reproduce more rapidly
d. the presence of the pathogen made the experiments too contaminated to trust the results
e. infection causes lymphocytes to divide more rapidly
e. infection causes lymphocytes to divide more rapidly
Explanation:
The cell cycle includes interphase and M phase which in turn together produce daughter cells from the existing parent cells. DNA replication occurs during the S phase of interphase to ensure that the daughter cells obtain the identical DNA present in the parent cell.
Lymphocytes are one of the types of white blood cells and are involved in cell-mediated and antibody-mediated immune responses. These cells are present in the blood as well as in lymphatic tissues. During the given experiment, lymphocytes exhibited a higher rate of incorporation of labeled nucleotide after the introduction of a pathogen in the culture. This suggests that the introduction of pathogen triggered the cell division in lymphocytes to produce more lymphocytes to fight the infection.
