Cell: The Unit of Life · Question 100

Which one of the following has its own DNA?

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

Which one of the following structures between two adjacent cells is an effective transport pathway?

1. Endoplasmic reticulum
2. Plasmodesmata
3. Plasmalemma
4. Plastoquinones

Middle lamella is composed mainly of :

1. Calcium pectate
2. Phosphoglycerides
3. Muramic acid
4. Hemicellulose

Cytoskeleton is made up of :

1. Cellulose microfibrils
2. Proteinaceous filaments
3. Calcium carbonate granules
4. Callose deposits

Plasmodesmata are :

1. Locomotory structures
2. Connection between adjacent cells
3. Membranes connecting the nucleus with plasmalemma
4. Lignified cemented layers between cells

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

In germinating seeds fatty acids are degraded exclusively in the:

1. proplastids
2. peroxisomes
3. glyoxysomes
4. mitochondria

Vacuole in a plant cell:

1. is membrane-bound and contains storage proteins and lipids
2. is membrane-bound and contains water and excretory substances
3. lacks membrane and contains air
4. lacks membrane and contains water and excretory substances

The two sub-units of ribosome remain united at a critical ion level of:

1. magnesium
2. manganese
3. calcium
4. copper

Keeping in view the "fluid mosaic model" for the structure of cell membrane, which one of the following statements is correct with respect to the movement of lipids and proteins from one lipid monolayer to the other (described as flip-flop movement)?

1. Both lipids and proteins can flip-flop
2. While lipids can rarely flip-flop proteins cannot
3. While proteins can flip-flop, lipids cannot
4. neither lipids, nor proteins can flip-flop