Engineering Questions with Answers - Multiple Choice Questions
MCQs on Bacterial Taxonomy
Mark the common feature between eukaryotes and prokaryotes.
a) Shape of DNA
b) Number of chromosomes
c) A prokaryotic cell is similar to a eukaryotic organelle
d) Cell wall
Explanation: In general, prokaryotes differs from the eukaryotic organism in every sense except its organelles i.e. mitochondria and chloroplast. It has to be believed that these organelles have been derived from bacteria as they share many common features (endosymbiotic theory).
Which of the following gene deduced the evolutionary relationship between the taxonomic groups?
a) 16S rRNA
b) 23S rRNA
c) 5S rRNA
d) 18S rRNA
Explanation: 16S ribosomal RNA acts as a signature sequence and is present in all the cells. These are approximately 1500bp in length. The organism of one taxonomic group has different conserved sequences than the other group.
Name the scientist who proposed the phylogenetic tree for living things.
a) Carlo Urbani
b) Louis Pasteur
c) Robert Koch
d) Carl Woese
Explanation: Carl Woese proposed the reorganization of five kingdoms into three kingdoms, based on the ribosomal RNA signature sequences. He placed protista, fungi, plants, and animals into a single group called eukaryotes.
. The largest bacteria which can be visible by unaided eye is_______
a) Thiomargarita namibiensis
Explanation: Thiomargarita namibiensis and epulopiscium fishelsoni are the largest bacteria of 600 micrometers in length and 75 micrometers in diameter and are easily visible to eyes.
. Which of the following is NOT the basic shape of the bacteria?
a) Rod shape
b) Square shape
c) Comma shape
d) Spiral shape
Explanation: There are four basic shapes of bacteria: rod shape is bacillus bacteria, comma shaped is vibrio bacteria, spiral shape is spirilla, and sphere shape of coccus.
What is sarcinae?
a) Cocci group of bacteria
b) Chainlike group of bacteria
c) Cubelike group of bacteria
d) Grapelike cluster of bacteria
Explanation: The division of bacteria into multiple groups form different structures like the chainlike division is called streptococci; the grapelike cluster is called staphylococci. Similarly, a group of eight bacteria into the cubelike structure is called sarcinae.
Which of the following bacteria is pleomorphic?
Explanation: Pleomorphic bacteria lack a single characteristic shape. Most of the bacteria are of monomorphic while corynebacterium is pleomorphic and has many shapes.
Gram staining is specialized staining.
Explanation: Bacterial staining is of three types: simple, differential, and specialized. Gram staining is a differential staining procedure used to differentiate bacterial species into gram positive and gram negative.
Name the acid present in the cell wall of bacteria which helps in retaining its color during the acid-fast test?
a) Mycolic acid
b) Teichoic acid
c) Malic acid
d) Tartaric acid
Explanation: Mycolic acid is present in the cell wall of acid-fast bacteria which helps in retaining its color during the acid-fast test while non acid-fast bacteria decolorized after reacting with acid-alcohol.
Which of the following organisms have thick peptidoglycan in their cell wall?
a) Gram-negative bacteria
b) Gram-positive bacteria
Explanation: Peptidoglycan is a specific feature of bacteria; it is present in the cell wall of bacteria and composed of NAG and NAM acid. Gram-negative bacteria have a thin peptidoglycan layer while gram-positive bacteria have a thick peptidoglycan layer.