Rod shaped bacteria are called
A) bacilli
B) vibrio
C) cocci
D) spirilla
The correct answer and explanation is :
The correct answer is A) bacilli.
Explanation:
Bacteria are classified into different shapes, and one of the most common categories is based on their shape, which helps in identifying them under a microscope. The shapes include bacilli, cocci, vibrio, and spirilla, each of which has distinct structural characteristics:
- Bacilli:
- Bacilli (singular: bacillus) are rod-shaped bacteria. They are elongated and cylindrical, resembling rods, and are often found in chains or individually. Bacilli can be aerobic (requiring oxygen) or anaerobic (able to live in the absence of oxygen).
- Bacillus species are a common group of bacteria that belong to this category. Some notable species include Bacillus anthracis, the causative agent of anthrax, and Bacillus subtilis, which is often used in laboratory settings.
- Cocci:
- Cocci are spherical or round-shaped bacteria. These bacteria can be found as single cells or in clusters or chains. Examples of cocci include Streptococcus and Staphylococcus, which are known for causing various human infections.
- Vibrio:
- Vibrio bacteria have a comma-shaped or curved rod shape. A well-known species of this group is Vibrio cholerae, the causative agent of cholera, which is characterized by a curved, rod-shaped structure.
- Spirilla:
- Spirilla are spiral-shaped bacteria. These bacteria are twisted and corkscrew-shaped, and some have flagella that allow them to move with a spiral motion. An example is Spirillum minus, which causes rat-bite fever.
In summary, bacilli refer to the rod-shaped bacteria, making option A the correct choice. Understanding the shape of bacteria is crucial for microbiologists, as it helps in the identification and classification of different bacterial species.