Final answer:
Cilia are used for moving cells like paramecia or moving substances along cell surfaces. Flagella enable the locomotion of single cells such as sperm or Euglena. Pseudopods are used by organisms like amoebas for movement or capturing prey.
Step-by-step explanation:
Physical characteristics like cilia, flagella, and pseudopods play specific roles in the lives of certain organisms.
- Cilia are short, hairlike structures composed of microtubules that can be many in number and cover the entire surface of a cell's plasma membrane. They are used for the locomotion of entire cells like paramecium or for the movement of substances along a cell's surface, such as the debris and mucus in the human respiratory tract.
- Flagella are long, hair-like structures that also extend from the plasma membrane and are used for moving an entire cell or an organism, such as sperm cells or the protist Euglena. A cell may have a single flagellum or a few flagella.
- Pseudopods or "false feet" are extensions of the cell that allow an organism, like an amoeba, to anchor itself and move or to capture prey.
- Pilli are not commonly used for holding onto rocks; they can be involved in bacterial adhesion to surfaces, but in the context of biology classwork, 'pilli' may be a typo and could refer to pili, which are hair-like structures on bacteria used for attachment or conjugation rather than holding onto rocks.