What are bacilli cocci and spirilla?

Cocci (or coccus for a single cell) are round cells, sometimes slightly flattened when they are adjacent to one another. Bacilli (or bacillus for a single cell) are rod-shaped bacteria. Spirilla (or spirillum for a single cell) are curved bacteria which can range from a gently curved shape to a corkscrew-like spiral.

How do you describe bacterial morphology?

1. Bacteria are complex and highly variable microbes. They come in four basic shapes: spherical (cocci), rod-shaped (bacilli), arc-shaped (vibrio), and spiral (spirochete) (Figure 1.3(A)).

How do bacilli and spirilla move?

Movement of Bacteria Bacilli and spirilla use hair-like extentions called flagella or cilia for movement.

What is the difference between bacilli and cocci?

The name “coccobacilli” is a combination of the words “cocci” and “bacilli.” Cocci are sphere-shaped bacteria, while bacilli are rod-shaped bacteria. Bacteria that fall between these two shapes are called coccobacilli.

Which bacteria form can be curved like a spiral?

Spirilla (sing. spirillum) shapes are curved-shaped bacteria which can range from a gently curved shape to a corkscrew spiral.

What best describes a virus?

A virus is an infectious particle that reproduces by “commandeering” a host cell and using its machinery to make more viruses. A virus is made up of a DNA or RNA genome inside a protein shell called a capsid. Some viruses have an external membrane envelope.

How would you describe bacterial colony morphology?

Colony morphology is a method that scientists use to describe the characteristics of an individual colony of bacteria growing on agar in a Petri dish. It can be used to help to identify them. A swab from a bin spread directly onto nutrient agar. Colonies differ in their shape, size, colour and texture.

What is the difference between cocci and bacilli?

The name “coccobacilli” is a combination of the words “cocci” and “bacilli.” Cocci are sphere-shaped bacteria, while bacilli are rod-shaped bacteria. Bacteria that fall between these two shapes are called coccobacilli. There are many species of coccobacilli, and some of them cause disease in humans.

How can you tell the difference between cocci and bacilli?

The average diameter of a bacterium in both cocci and bacilli is around 0.5 µm. The main difference between cocci and bacilli is that cocci are spherical or oval-shaped bacteria whereas bacilli are rod-shaped bacteria.