Biology Multiple Choice Questions on “Prokaryotic Cells”.
1. What is the full form of PPLO?
a) Pleural Parasite Like Organisms
b) Phosphatic Pneumonia Like Organisms
c) Pleuro Parasite Like Organisms
d) Pleuro Pneumonia Like Organisms
Answer: d
Clarification: The full form of PPLO is Pleuro Pneumonia Like Organisms. They are a type of prokaryotic organisms, which also include bacteria, blue – green algae and mycoplasma. The lack a true nucleus.
2. Which of these is not a basic shape of bacteria?
a) Vibrio
b) Spirillum
c) Triangular
d) Coccus
Answer: c
Clarification: Bacteria have four basic shapes. These are bacillus or rod – shaped, coccus or spherical shape, vibrio or comma shaped and spirillum or spiral shaped. Bacteria are a type of prokaryotic organisms.
3. Which of these bacteria lack a cell wall?
a) Escherichia
b) Pseudomonas
c) Mycoplasma
d) Mycobacterium
Answer: c
Clarification: All bacteria have a cell wall covering the cell membrane, except in the genus mycoplasma. Since all bacteria are prokaryotic organisms, they do not have a well – defined nucleus. The genetic material is naked.
4. What is the size of a typical eukaryotic cell?
a) 10 – 20 μm
b) 0.1 – 0.2 μm
c) 100 – 200 μm
d) 1 – 2 μm
Answer: a
Clarification: The size of a typical eukaryotic cell is 10 – 20 μm. Prokaryotic cells are generally smaller than eukaryotic cells and also multiply more rapidly. Bacteria, blue-green algae, mycoplasma and PPLO (Pleuro Pneumonia Like Organisms) are the types of prokaryotic cells.
5. What is the shape of a bacterial plasmid?
a) Linear
b) Circular
c) Irregular
d) Bacillus
Answer: b
Clarification: Plasmids are extrachromosomal small circular DNA that is present in bacterial cell, apart from the genomic DNA. Plasmid DNA confers several special features to the cell such as resistance to certain chemicals.
6. What are plasmid made of?
a) Proteins
b) Polysaccharides
c) Nucleic acids
d) Lipids
Answer: c
Clarification: Plasmids are made of nucleic acids. They are extrachromosomal small circular DNA that is present in bacterial cell, apart from the genomic DNA. Plasmid DNA confers several special features to the cell.
7. Which of these structures is used in bacterial transformation?
a) Plasmid
b) Cell membrane
c) Ribosomes
d) Genomic DNA
Answer: a
Clarification: Plasmids are made of nucleic acids. They are extrachromosomal small circular DNA that is present in bacterial cell, apart from the genomic DNA. They are used as vectors for bacterial transformation.
8. From which structure is a mesosome derived from?
a) Plasmid
b) Cell wall
c) Ribosome
d) Cell membrane
Answer: d
Clarification: Mesosome is a characteristic feature of prokaryotes, which is not present in eukaryotic cells. It is a differentiated form of cell membrane derived by the infoldings of the cell membrane in prokaryotes.
9. How many layers are present in the bacterial cell envelope?
a) 1
b) 2
c) 3
d) 4
Answer: c
Clarification: Bacterial have a tightly bound three – layered cell envelope. The uppermost layer is the glycocalyx, followed by the cell wall in the middle and the innermost plasma membrane. The cell envelope provides protection.
10. Gram negative bacteria take up gram strain. True or false?
a) True
b) False
Answer: b
Clarification: Bacteria are classified into Gram – positive bacteria and Gram – negative bacteria on the basis of their response to a staining procedure known as Gram staining. Gram positive bacteria take up gram strain.
11. Which of these bacteria have chromatophores?
a) Escherichia
b) Mycobacteria
c) Mycoplasma
d) Cyanobacteria
Answer: d
Clarification: Chromatophores are pigment containing membranous extensions in the cytoplasm of bacteria. Cyanobacteria contain chromatophores. They are photosynthetic bacteria that are aquatic in nature.
12. Which of these structures is not a part of the bacterial flagella?
a) Filament
b) Basal Body
c) Lamina
d) Hook
Answer: c
Clarification: Motile bacteria have a thin filamentous structure extending from the cell known as the flagella. Flagella are made of three parts – the filament which is the longest portion, the hook and the basal body.
13. Which of these is not a surface structure in bacteria?
a) Flagella
b) Pili
c) Mesosome
d) Fimbriae
Answer: c
Clarification: Flagella, pili and fimbriae are structures present on the surface of the bacterial cell for various purposes such as motility and attachment. Mesosome is an infolding of cell membrane, present in the cytoplasm.
14. What are the subunits of prokaryotic ribosomes?
a) 50S, 30S
b) 60S, 40S
c) 70S, 30S
d) 60S, 30S
Answer: a
Clarification: Prokaryotes have a 70S ribosome and eukaryotes have an 80S ribosome. The 70S prokaryotic ribosome contains one large 50S subunit and one small 30S subunit. It is site of protein synthesis.
15. Which of these statements is not true regarding inclusion bodies in prokaryotes?
a) Reserve material is stored in these structures
b) They are bound by a single membrane
c) Gas vacuoles are found in blue-green bacteria
d) They lie free in the cytoplasm
Answer: b
Clarification: Inclusion bodies are not covered by membranes and lie freely in the cytoplasm. They store reserve material such as phosphate granules. blue-green bacteria contain gas vacuoles which is an inclusion body.