Cell: The Unit of Life

The motile bacteria are able to move by

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

The solid linear cytoskeletal elements having a diameter of 6 nm and made up of a single type of monomer are known as:

1. Microfilaments
2. Lamins
3. Microtubules
4. Intermediate filaments

The osmotic expansion of a cell kept in water is chiefly regulated by:

1. Vacuoles
2. Plastids
3. Mitochondria
4. Ribosomes

Pigment containing membranous extensions in some cyanobacteria are

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

The Golgi complex plays a major role :

1. as energy transferring organelles
2. in post translational modification of proteins and glycosidation of lipids
3. in trapping the light and transforming it into chemical energy
4. in digesting proteins and carbohydrates

Which one of the following organelle in the figure correctly matches with its function ? [Figure]

1. Golgi apparatus, formation of glycolipids
2. Rough endoplasmic reticulum, formation of glycoproteins
3. Rough endoplasmic reticulum, protein synthesis
4. Golgi apparatus, protein synthesis

A major site for synthesis of lipids is :

1. RER
2. Nucleoplasm
3. SER
4. Symplast

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 of the following types of plastids does not contain stored food material ?

1. Elaioplasts
2. Chromoplasts
3. Amyloplasts
4. Aleuroplasts

Select the alternative giving correct identification and function of the organelle 'A' in the diagram [Figure]

1. Golgi body - provides packaging material
2. Mitochondria - produce cellular energy in the form of ATP
3. Endoplasmic reticulum - synthesis of lipids
4. Lysosomes - secrete hydrolytic enzymes

Which one of the following cellular parts is correctly described ?

1. Lysosomes - optimally active at a pH of about 8.5
2. Centrioles - sites for active RNA synthesis
3. Thylakoids - flattened membranous sacs forming the grana of chloroplasts
4. Ribosomes - those on chloroplasts are larger (80S) while those in the cytoplasm are smaller (70S)

Which one of the following structures is an organelle within an organelle ?

1. Mesosome
2. Peroxisome
3. Ribosome
4. ER

Ribosomal RNA is actively synthesized in

1. Nucleolus
2. Ribosomes
3. Lysosomes
4. Nucleoplasm

Select the correct statement from the following regarding cell membrane

1. Na+ and K+ ions move across cell membrane by passive transport
2. Lipids are arranged in bilayer with polar heads towards the inner part
3. Proteins make up 60 to 70% of the cell membrane
4. Fluid mosaic model of cell membrane was proposed by Singer and Nicolson

What is true about ribosomes ?

1. These are self-splicing introns of some RNAs.
2. These are found only in eukaryotic cells
3. These are composed of ribonucleic acid and proteins
4. The prokaryotic ribosomes are 80 S, where 'S' stands for sedimentation coefficient.

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

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

Which one of the following is not considered as a part of the endomembrane system ?

1. Vacuole
2. Lysosome
3. Golgi complex
4. Peroxisome

The figure below shows the structure of a mitochondrion with its four parts labelled (A), (B), (C) and (D). Select the part correctly matched with its function. [Figure]

1. Part (B) : Inner membrane – forms infoldings called cristae
2. Part (C) : Cristae – possess single circular DNA molecule and ribosomes
3. Part (A) : Matrix – major site for respiratory chain enzymes
4. Part (D) : Outer membrane – gives rise to inner membrane by splitting

In eubacteria, a cellular component that resembles eukaryotic cell is

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

Which one of the following organisms is not a eukaryote?

1. Paramecium caudatum
2. Escherichia coli
3. Euglena viridis
4. Amoeba proteus

Peptide synthesis inside a cell takes place in :

1. Chromoplast
2. Ribosomes
3. Chloroplast
4. Mitochondria

Important site for formation of glycoproteins and glycolipids is :

1. Plastid
2. Lysosome
3. Golgi apparatus
4. Vacuole

An elaborate network of filamentous proteinaceous structures present in the cytoplasm which helps in the maintenance of cell shape is called -

1. Cytoskeleton
2. Endoplasmic Reticulum
3. Thylakoid
4. Plasmalemma

Identify the components labelled A, B, C and D in the diagram below from the list (i) to (viii) given along with – [Figure] Components : (i) Cristae of mitochondria (ii) Inner membrane of mitochondria (iii) Cytoplasm (iv) Smooth endoplasmic reticulum (v) Rough endoplasmic reticulum (vi) Mitochondrial matrix (vii) Cell vacuole (viii) Nucleus The correct components are :

1. (A) (v), (B) (iv), (C) (viii), (D) (iii)
2. (A) (i), (B) (iv), (C) (viii), (D) (vi)
3. (A) (v), (B) (i), (C) (iii), (D) (ii)
4. (A) (vi), (B) (v), (C) (iv), (D) (vii)

Membrane-bound organelles are absent in

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

Algae have cell wall made up of:

1. cellulose, galactans and mannans
2. hemicellulose, pectins and proteins
3. pectins, cellulose and proteins
4. cellulose, hemicellulose and pectins

The plasma membrane consists mainly of –

1. proteins embedded in a carbohydrate bilayer
2. phospholipids embedded in a protein bilayer
3. proteins embedded in a phospholipid bilayer
4. proteins embedded in a polymer of glucose molecules

The main area of various types of activities of a cell is –

1. Cytoplasm
2. Plasma membrane
3. Nucleus
4. Mitochondrion

Which one of the following has its own DNA?

1. Dictyosome
2. Mitochondria
3. Peroxisome
4. Lysosome