Cell: The Unit of Life

Which of the following are characteristics of prokaryotic cells?

1. (A), (B) and (C) only
2. (B) and (C) only
3. (A) and (C) only
4. (A), (C) and (D) only

A specialised membranous structure in a prokaryotic cell which helps in cell wall formation, DNA replication and respiration is

1. Cristae
2. Endoplasmic Reticulum
3. Mesosome
4. Chromatophores

Mesosome in a cell is a :

1. Membrane bound vesicular structure
2. Chain of many ribosomes attached to a single mRNA
3. Special structure formed by extension of plasma membrane
4. Medium sized chromosome

Pathogenic bacteria gain resistance to antibiotics due to changes in their :

1. Nucleoid
2. Cosmids
3. Plasmids
4. Nucleus

Which of the following statements about inclusion bodies is incorrect?

1. These are involved in ingestion of food particles
2. They lie free in the cytoplasm
3. These represent reserve material in cytoplasm
4. They are not bound by any membrane

Which of the following components provides sticky character to the bacterial cell?

1. Nuclear membrane
2. Plasma membrane
3. Glycocalyx
4. Cell wall

DNA replication in bacteria occurs

1. within nucleolus
2. prior to fission
3. just before transcription
4. during S phase

Select the mismatch.

1. Large central vacuoles – Animal cells
2. Methanogens – Prokaryotes
3. Gas vacuoles – Green bacteria
4. Protists – Eukaryotes

Select the wrong statement-

1. Pili and fimbriae are mainly involved in motility of bacterial cells
2. Mycoplasma is a wall-less microorganism
3. Bacterial cell wall is made up of peptidoglycan
4. Cyanobacteria lack flagellated cells.

The structures that help some bacteria to attach to rocks and/or host tissues are

1. mesosomes
2. holdfast
3. rhizoids
4. fimbriae.

Chromatophores take part in

1. movement
2. respiration
3. photosynthesis
4. growth.

Which of the following structures is not found in a prokaryotic cell?

1. Mesosome
2. Nuclear envelope
3. Ribosome
4. Plasma membrane

Which one of the following is not an inclusion body found in prokaryotes?

1. Cyanophycean granule
2. Phosphate granule
3. Polysome
4. Glycogen granule

Which structures perform the function of mitochondria in bacteria?

1. Nucleoid
2. Ribosomes
3. Cell wall
4. Mesosomes

The motile bacteria are able to move by

1. fimbriae
2. flagella
3. cilia
4. pili.

Pigment containing membranous extensions in some cyanobacteria are

1. pneumatophores
2. chromatophores
3. heterocysts
4. basal bodies.

Why is a capsule advantageous to a bacterium?

1. It protects the bacterium from desiccation.
2. It provides means of locomotion
3. It allows bacterium to "hide" from host's immune system.
4. It allows the bacterium to attach to the surface.

The term 'glycocalyx' is used for :

1. bacterial cell glyco-engineered to possess N-glycosylated proteins
2. a layer present between cell wall and membrane of bacteria
3. a layer surrounding the cell wall of bacteria
4. cell wall of bacteria

Which one of the following does not differ in E. coli and Chlamydomonas ?

1. Chromosomal Organization
2. Cell wall
3. Ribosomes
4. Cell membrane

In eubacteria, a cellular component that resembles eukaryotic cell is

1. plasma membrane
2. nucleus
3. ribosomes
4. cell wall

Membrane-bound organelles are absent in

1. Saccharomyces
2. Streptococcus
3. Chlamydomonas
4. Plasmodium

Polysome is formed by

1. several ribosomes attached to a single mRNA
2. many ribosomes attached to a strand of endoplasmic reticulum
3. a ribosome with several subunits
4. ribosomes attached to each other in a linear arrangement

Chromosomes in a bacterial cell can be 1–3 in number and

1. are always circular
2. are always linear
3. can be either circular or linear, but never both within the same cell
4. can be circular as well as linear within the same cell.

In bacteria, plasmid is

1. extra chromosomal material
2. main DNA
3. non functional DNA
4. repetitive gene.

Difference in gram positive and gram negative bacteria is due to

1. cell wall
2. cell membrane
3. ribosome
4. cytoplasm