A diploid cell with an initial chromosome number of 2N and DNA content of 2C is treated with a spindle-poison. The cell undergoes the cell cycle but is arrested just after the splitting of centromeres due to the complete inhibition of spindle fiber formation. Read the following statements regarding the state of this cell at the point of arrest: (A) The DNA content of the cell becomes 4C . (B) The chromosome number of

Step-by-step solution

Let us evaluate each statement for a cell treated with a spindle poison and arrested after centromere splitting: (A) Correct: The cell has passed through the S-phase before entering mitosis, so its DNA content has doubled from 2C to 4C . (B) Correct: The splitting of centromeres converts sister chromatids into independent chromosomes. Since the initial chromosome number was 2N , splitting doubles it to 4N . Because the spindle is poisoned, the cell does not divide, retaining the 4N number. (C) Incorrect: This is a