During mitosis, what is actually being duplicated?

• A. Mitochondria
• B. Ribosomes
• C. Cell membrane
• D. Chromosomes

Answer: (D)

Verified step by step guidance

1. Understand the process of mitosis: Mitosis is a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.
2. Identify the key components involved in mitosis: During mitosis, the primary focus is on the duplication and separation of chromosomes, which are structures within the cell that contain DNA.
3. Clarify the role of chromosomes: Chromosomes are duplicated during the S phase of the cell cycle, prior to mitosis, ensuring that each daughter cell receives an identical set of chromosomes.
4. Differentiate between organelles and chromosomes: While mitochondria, ribosomes, and the cell membrane are important cellular components, they are not the primary focus of duplication during mitosis. The duplication of these components occurs through other cellular processes.
5. Conclude with the correct answer: The correct answer to the question is chromosomes, as they are the structures that are duplicated and segregated during mitosis to ensure genetic consistency in daughter cells.