Question

Which of the following is a feature of aging cells?

• A. Lipofuscin accumulation
• B. Increased oxidative phosphorylation
• C. Increased glycogen stores
• D. Increased nuclear material and mitochondria

Hint:

Lipofuscin, the wear-and-tear pigment, builds up steadily inside long-lived aging cells like neurons and cardiac myocytes.

Answer 1

The Correct Option is A

Step 1: Recall what happens as a cell ages.
Over years, long lived cells like neurons and cardiac muscle cells build up damage that their repair systems cannot fully clear. One visible result of this is the buildup of lipofuscin, often called the wear and tear pigment.

Step 2: Understand where lipofuscin comes from.
Lysosomes are constantly breaking down damaged organelles and oxidized lipids. What they cannot fully digest is left behind as a yellow brown, granular pigment that keeps piling up inside the cell with each round of damage and incomplete clearance. This is exactly why lipofuscin is used as a marker of cellular aging under the microscope.

Step 3: Check the other options against what actually happens in aging.
Aging cells do not gain more oxidative phosphorylation, they lose it, because mitochondrial DNA picks up mutations over time and respiratory enzyme function drops. Aging cells do not build up more glycogen either, their overall metabolic reserve and efficiency tend to fall instead. Aging cells also do not gain more nuclear material or more mitochondria, if anything the nuclear envelope becomes irregular and mitochondria become fewer and abnormal in shape.

Step 4: Final answer.
The true feature of aging cells among these options is
\[ \boxed{\text{Lipofuscin accumulation}} \]