12
Mark the mismatched pair.
| Column I | Column II | ||
|---|---|---|---|
| A. | Amyloplast | (i) | Store protein granule |
| B. | Elaioplast | (ii) | Store oils or fats |
| C. | Chloroplasts | (iii) | Contain chlorophyll pigments |
| D. | Chromoplasts | (iv) | Contain coloured pigments other than chlorophyll |
Explanation
Amyloplasts are the colourless plastids which store starch but not the protein granules. Other pairs are correctly matched.
13
Smaller, lipid soluble molecules diffuse faster through cell membrane, but the movement of hydrophilic substances are facilitated by certain transporters which are chemically ........... .
Explanation
Proteins.
The movement of hydrophilic substances are facilitated by transporters which are chemically proteins. These proteins form porins, which are huge pores in the outer membranes of the plastids, mitochondria and some bacteria. These porins allow the small molecules to pass through the membrane.
14
In a passive transport across a membrane. When two protein molecules move in opposite direction and independent of each other, it is called as ........... .
Explanation
Antiport This process facilitates transport of molecules in both the directions across the membrane and their movement is independent of each other.
15
Osmosis is a special kind of diffusion, in which water diffuses across the cell membrane. The rate and direction of osmosis depends upon both ............. .
Explanation
The rate and direction of osmosis depends upon both the pressure gradient and concentration gradient.
16
A flowering plant is planted in an earthen pot and irrigated. Urea is added to make the plant grow faster, but after sometime the plant dies. This may be due to ............. .
Explanation
The plant dies due to exosmosis. As the solution outside the plant is an hypertonic solution, and the plant celsl are hypotonic in nature, so there is a gradual movement of water from plant cell to outside urea solution leading to plasmolysis of root cells and plant dies gradually.