Cell: The Unit of Life

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

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