Question

1) When viewing a mixed culture of bacteria under a microscope, you notice that there is significant diversity in their arrangements and shapes.Describe the types of bacterial cell arrangements and what determines the diversity in these arrangements.Explain why Bacilli are less varied in arrangement than cocci? (Minimum length : 150 words).

Answer 1

1) The arrangement of bacterial cell is divided into 3 shapes:

Bacillus, coccus, and spiral.

Coccus: The cocci are spherical or oval bacteria having one of several distinct arrangements. Eg. Staphylococcus aureus.

Bacillus: Bacilli are rod-shaped bacteria. Bacilli all divide in one plane producing a bacillus, streptobacillus, or coccobacillus arrangement. Eg. Lactobacillus.

Spiral: Spirals come in one of three forms, a vibrio, a spirillum, or a spirochete. Eg. vibrio cholerae.

2) There are different  kind of shapes are found in bacterial cell like cocci, bacilli, spiral and comma. It's the cell division which decide the arrangement of cells in bacteria at various plane of axis. In case of cocci ( spherical in shape) different arrangements of cells have been identified which include diplococcus, streptococcus, tetrococcus, staphylococcus. Incase of bacilli different arrangements takes place through single plane cell division which results in bacillus, streptobacilli, cocobacilli. In case of spiral there are three different forms include in it such as vibrio, spirillum, spirochetes. Bacillus are less varied in arrangement than cocci because bacillus can only divide end to end in single plane of division and lead to the formation of chain like arrangements where as cocci can form different type of arrangements of cells as they can divide in variious planes of division.