Question

The shape of the bacteria shown in the figure is

A. Bacilli
B. Cocci
C. Vibrio
D. Spirillum

Answer 1

Kingdom Monera comprises single-celled prokaryotic organisms. Different shapes of bacteria are Bacillus (Rod-shaped), Cocci (Spherical), Spirillum (Spiral) and Vibrio (Comma-like).

Complete answer: Kingdom Monera comprises the microscopic single-celled prokaryotic organisms of which Bacteria are the sole members. They are present almost everywhere. Most bacterial organisms bear a rigid cell wall that consists of peptidoglycans, lipid proteins, amino acids, etc. Their genetic material is a naked, circular DNA, also called a nucleoid or genophore. The ribosomes are of the 70S type. Since they are prokaryotes, all membrane-bound organelles are absent. Sap vacuoles do not occur. Instead, gas vacuoles may be present. These creatures are either non-motile or some move by the beating of the basic flagella. Flagella, if present, are made out of many interlaced chains of the protein flagellin. The bacterial structure is very simple but they are very complex in behaviour. It is a group which shows the most extensive metabolic diversity. The smallest bacterium is Dialister pneumosintes. Different shapes of bacteria are Bacillus (Rod-shaped), Cocci (Spherical), Spirillum (Spiral), Vibrio (Comma-like).
Vibrio is a genus of the gram-negative (based on staining) bacteria that have a comma-like curved shape. Vibrio cholerae causes the disease cholera. Mode of infection is contaminated food and water or direct contact. Symptoms of the disease include severe diarrhoea, vomiting, stool like rice water.
So, the correct answer is option C.

Note: Based on the presence or absence of flagella, the bacteria is of divided into the following categories:
a) Atrichous – when the flagellum is missing(absent)it is called atrichous.
b) Monotrichous – only one flagellum is found at one end.
c) Amphitrichous – when a single flagellum is present at both the ends.
d) Cephalotrichous - when a group of flagella (tuft) is present at one end only.