1. | Exine of pollen grains is made up of sporopollenin |
2. | Pollen grains of many species cause severe allergies |
3. | Stored pollen in liquid nitrogen can be used in crop breeding programs |
4. | Tapetum helps in the dehiscence of anther |
1. | connective | 2. | placenta |
3. | thalamus or petal | 4. | anther |