Question

These thin proteinaceous structures that originate in the cytoplasm and project out from the cell wall are the most common means of motility in bacteria.

a) Cilia
b) Flagella
c) Pili
d) Microvilli

Answer 1

Flagella and cilia are thin proteinaceous structures in bacteria used for motility. Flagella are long hair-like structures that move an entire cell, while cilia are short hair-like structures that move entire cells or substances along the cell's outer surface.

Step-by-step explanation:

Flagella (singular = flagellum) are long, hair-like structures that extend from the plasma membrane and are used to move an entire cell. When present, a cell has just one flagellum or a few flagella. Cilia (singular cilium) are short, hair-like structures that are used to move entire cells or to move substances along the outer surface of the cell. For example, the cells lining the ovarian tubes have cilia that move the ovum toward the uterus, and the cells lining the respiratory tract have cilia that move mucus toward your nostrils. When cilia are present, they extend along the entire surface of the plasma membrane.