What Cells Do Not Have DNA?

Cells that do not have DNA include mature red blood cells (in mammals) and dead cells like outermost skin cells, nail cells, and hair cells.

Cells Lacking DNA: A Closer Look

While most cells in the body contain DNA, which is essential for carrying genetic information and directing cellular processes, there are exceptions. These exceptions are generally cells that have either expelled their DNA during maturation or are dead and thus no longer require it.

Mature Red Blood Cells (Erythrocytes)

• Function: Red blood cells are responsible for transporting oxygen throughout the body.
• DNA Loss: Mammalian red blood cells expel their nucleus (and therefore their DNA) during maturation to create more space for hemoglobin, the oxygen-carrying protein. This allows them to carry more oxygen.
• Note: Red blood cells in other vertebrates like birds and amphibians do retain their nuclei and therefore their DNA.

Dead Cells: Skin, Nail, and Hair

• Barrier and Insulation: Our outermost skin cells, nail cells, and hair cells lack DNA because they are dead cells.
• No Internal Processes: These cells do not have any internal processes going on.
• Protective Role: They function as a barrier and insulator, protecting the body from harm.
• Reference: As stated, "outermost skin cells, nail cells and hair cells don't have DNA either – but that's because they have no processes going on inside them at all – they're dead cells which act as a barrier and insulator to protect our body from harm."

Summary Table: Cells Without DNA