In a bacterium, pili are typically _______ than flagella.

• A. shorter
• B. thicker
• C. longer
• D. more numerous

Answer: (A)

Verified step by step guidance

1. Understand the structures involved: Pili and flagella are both appendages found on bacterial cells, but they serve different functions and have different physical characteristics.
2. Recall the function of pili: Pili are primarily involved in attachment to surfaces and in conjugation (transfer of genetic material), so they are generally designed to be numerous and short to maximize surface contact.
3. Recall the function of flagella: Flagella are used for motility, allowing bacteria to swim. Because they need to propel the cell, they are typically longer and fewer in number compared to pili.
4. Compare the physical characteristics: Since pili are meant for attachment and are numerous, they tend to be shorter and thinner than flagella, which are longer and thicker to aid in movement.
5. Conclude that in a bacterium, pili are typically shorter than flagella, which aligns with their functional roles and structural differences.