Question

You examine an epithelial cell (skin cell) and notice the chromosomes are visible however it appears there are two nuclei in the cell. What is the best explanation for this observation?
a) the cell has just gone through the S –phase of the cell cycle so there is double the amount of DNA
b) the cell has just gone through telophase but not cytokinesis
c) the cell has gone through meiosis I and is preparing for meiosis II
d) the cell is in G1 and is preparing for DNA synthesis

Answer 1

Answer:

The best explanation if we observe an epithelial cell with chromosomes are visible and two cell nuclei is that the cell has just gone through telophase but not cytokinesis (option b).

Explanation:

A somatic cell, when found in mitosis, exhibits the chromosomes distributed in both poles and the outline of two nuclei in the telophase phase, just before cytokinesis.

In mitotic telophase:

• Chromatids, which are chromosomes, are found in the cell poles.
• It initiates the formation of the nucleus membrane.
• The chromosomes begin to turn into chromatin.
• Disappearance of the mitotic spindle, duplication of organelles and cytoplasmic invagination.

The division and differentiation of the nuclei in telophase is called karyokinesis. Later, cytokinesis occurs, where the daughter cells are separated.

The other options are not correct because:

    a and d. In the other phases described, S and G1, no chromosome distribution is observed at the poles.

    c. A somatic cell does not experience meiosis.