Mitosis preserves chromosome number in daughter cells

Steps:

• Cell X starts with 24 chromosomes in its nucleus.
• During mitosis, chromosomes duplicate to 48, then split equally.
• The cell divides into two daughter cells, Y and Z.
• Each daughter receives one full set of 24 chromosomes.

Why B is correct:

• Mitosis definition: Daughter cells are genetically identical to the parent, retaining the same diploid chromosome number (24 here).

Why the others are wrong:

• A. 12: Half the number occurs in meiosis I, not mitosis.
• C. 46: Standard human diploid count, unrelated to this cell's 24.
• D. 48: Temporary duplicated amount before division, not final in Z.

Final answer: B