What happens to cells when they become senescent?

• A. They die immediately
• B. They stop dividing and remain metabolically active
• C. They multiply rapidly
• D. They become stem cells

Answer: (B)

Cellular senescence is a state where a cell permanently stops dividing in response to stress or damage, yet stays alive and metabolically active. The cell can no longer progress through the cell cycle, so it won’t replicate, but its basic metabolic processes continue, and it often releases signaling molecules (the SASP) that affect the surrounding tissue. This combination—no division, but ongoing metabolism—fits the description of senescent cells best. They aren’t dying immediately, they aren’t multiplying rapidly, and they don’t become stem cells. Senescence serves to prevent damaged cells from dividing, which helps stop cancer, but the accumulation of senescent cells can contribute to aging and tissue decline.