Bacteria having a tuft of flagella at one end are called

1. Peritrichous
2. Monotrichous
3. Lophotrichous
4. Amphitrichous

There are four types of flagellar arrangements based on the number and placement of flagella on the cell. These are,

1. Monotrichous - A single flagellum extends from one end of the cell.

2. Amphitrichous - A single flagellum or multiple flagella extend from two ends of the cell.

3. Lophotrichous - Tuft of flagella extend from one end or both ends of the cell.

4. Peritrichous - Multiple flagella randomly distributed over the entire bacterial cell.

Thus, the correct answer is 'Lophotrichous.'