Question

Which of the following terms refers to a bacterial cell having a single tuft of flagella at one end? a. monotrichous b. amphitrichous c. peritrichous d. lophotrichous

Short answer

d. lophotrichous

Step-by-step solution

- Understanding the Terms

We need to understand the different types of flagellar arrangements to solve this question. The four options given indicate different flagellar arrangements on bacterial cells.

- Define Monotrichous

Monotrichous refers to a bacterial cell having a single flagellum at one end.

- Define Amphitrichous

Amphitrichous describes a bacterial cell with one flagellum at each end.

- Define Peritrichous

Peritrichous means that flagella are distributed all around the bacterial cell's surface.

- Define Lophotrichous

Lophotrichous refers to a bacterial cell having a tuft (cluster) of flagella at one or both ends.

- Find the Matching Term

From the definitions, the term that matches ‘a bacterial cell having a single tuft of flagella at one end’ is 'lophotrichous'.

Key concepts

Monotrichous

Monotrichous bacteria have a single flagellum at one end of their cell. Think of it as a tail that helps the bacteria move. This flagellum rotates to help the cell propel forward through its environment. If you imagine a tiny motorboat with one propeller, you've got the right idea! 

Monotrichous flagella arrangements allow for precise movement, making it easier for the bacteria to reach targets like food sources or evade harmful substances.

Amphitrichous

Amphitrichous bacteria have one flagellum at each end of the cell. This means they have two flagella in total, positioned oppositely.

This arrangement allows the bacteria to change direction quickly since they can coordinate movements by switching which flagellum is active. It's like having a paddle on each side of a kayak, enabling quick turns and movement adjustments.

This type of arrangement is less common but provides flexibility in navigating through their environment.

Peritrichous

Peritrichous bacteria have flagella distributed all over their surface. Imagine a tiny cell covered in tiny whips or hairs all around it.

This arrangement allows for very efficient movement in all directions. Because the flagella are spread out, the bacteria can move smoothly through liquids by tumbling and running, which helps them explore their surroundings effectively.

Many bacteria with this arrangement can move toward or away from chemical signals through a process called chemotaxis, aiding in survival and finding nutrients.

Lophotrichous

Lophotrichous bacteria have a tuft or cluster of flagella at one or both ends of the cell. This is like having a bunch of propellers at one end, creating more powerful thrusts.

With this arrangement, the bacteria are equipped to move more forcefully and with greater control, especially when navigating thick or viscous environments.

When flagella are in a group rather than spread out, they can work together more efficiently to propel the cell, similar to multiple oars rowing in unison on a boat.