Final answer:
Flagella are long, hair-like structures used for cell motility, especially in watery environments. Flagella staining is a common method used to observe these thin structures. The organization of microtubules and motor proteins within flagella enable cell movement.
Step-by-step explanation:
Flagella are crucial organelles for cell motility, particularly in aqueous environments. They appear as long, hair-like structures that extend from the plasma membrane of cells such as sperm and certain single-celled organisms like Euglena. The function of flagella is to propel the cell through its environment, working similarly to a propeller.
To observe and study these structures, flagella staining is commonly used as they are too thin to be viewed under normal light microscopy. The staining technique involves the use of a mordant to coat and thicken the flagella, followed by staining with dyes such as pararosaniline or basic fuchsin. Additionally, the structure of flagella serving the purpose of locomotion can be seen consisting of 9 double rings of microtubules, 2 central microtubules, and motor proteins like dynein and kinesin for movement.