Flagella may best be described as:
1. filamentous rotating structures which porvide motility, may be singular, paired or scattered.
2. long serveral per cell, join bacteria for exchange of genetic information
3. bundles of fibrils which arise at the end of and spiral around the cell
4. highly durable dehydrated structure which contain a copy of the cell's dna

The correct answer is number one: Filamentous rotating structures that provide motility may be singular, paired or scattered.

Explanation:

Flagella are organelles defined by function rather than structure.

The primary function is that of locomotion but also being sensitive to chemicals and temperatures outside the cell.

Helicobacter pylori is a good example of flagella: It uses multiple flagella to propel itself through the mucus lining to reach the stomach epithelium.

Sperm cell is a good example, which uses its flagellum to propel itself through the reproductive tract of females.

I hope it helps!

1. filamentous rotating structures which porvide motility, may be singular, paired or scattered.

Explanation:

"Bacterial flagella are helically shaped structures containing the protein flagellin. The base of the flagellum (the hook) near the cell surface is attached to the basal body enclosed in the cell envelope. The flagellum rotates in a clockwise or counterclockwise direction, in a motion similar to that of a propeller."

Reference: Britannica, The Editors of Encyclopaedia. “Flagellum.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 2019

the dna molecules have a negative charge because of the phosphate groups in their sugar-phosphate backbone, so they start moving through the matrix of the gel towards the positive pole. power is turned on and dna fragments migrate through gel (towards the positive electrode).

explanation: