How many cells are in the human body?

• 30 billion

• 30 million

• 30 trillion

• 30 thousand

Approximately how many new cells replace old ones in the human body every day?

• 33 million

• 330 million

• 3.3 billion

• 33 billion

How often does the intestinal lining renew itself?

• Every 1-2 days

• Every 3-5 days

• Every week

• Every month

What is the approximate lifespan of red blood cells before they are replaced?

• 30 days

• 60 days

• 90 days

• 120 days

What type of cells are responsible for the constant regeneration and maintenance of the human body?

• Somatic cells

• Nerve cells

• Stem cells

• Muscle cells

Which of the following is a unique ability of stem cells?

• They can only form skin cells

• They cannot divide

• They can self-renew to create more stem cells

• They are terminally differentiated

Besides self-renewal, what is another unique ability of stem cells?

• They can only differentiate into one specific cell type

• They can differentiate into many different types of cells

• They are unable to differentiate

• They only form blood cells

What is a key characteristic of somatic cells like skin, muscle, or brain cells, as opposed to stem cells?

• They can self-renew indefinitely

• They can differentiate into any cell type

• They cannot divide

• They are responsible for regeneration