The main arena of various types of activities of a cell is
1. plasma membrane
2. mitochondrion
3. cytoplasm
4. nucleus
The plasma membrane consists mainly of
| 1. | phospholipids embedded in a protein bilayer |
| 2. | proteins embedded in a phospholipid bilayer |
| 3. | proteins embedded in a polymer of glucose molecules |
| 4. | proteins embedded in a carbohydrate bilayer |
Stroma in the chloroplasts of higher plants contains
| 1. | light-independent reaction enzymes |
| 2. | light-dependent reaction enzymes |
| 3. | ribosomes |
| 4. | chlorophyll |
Middle lamella is mainly composed of
1. hemicellulose
2. muramic acid
3. calcium pectate
4. phosphoglycerides
Plasmodesmata are
| 1. | lignified cemented layers between cells |
| 2. | locomotory structures |
| 3. | membranes connecting the nucleus with plasmalemma |
| 4. | connections between adjacent 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 |
The two subunits of ribosome remain united at a critical ion level of
1. copper
2. manganese
3. magnesium
4. calcium
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 |
In germinating seeds fatty acids are degraded exclusively in the
1. proplastids
2. glyoxysomes
3. peroxisomes
4. mitochondria
Which one of the following is not a constituent of cell membrane ?
1. Cholesterol
2. Glycolipids
3. Proline
4. Phospholipids