Difference between Vegetative and Generative Cell
The cytoplasm of the vegetative cell and the generative cell is distinctly different. The generative cell is transparent and contains almost no RNA. The cytoplasm of vegetative cell is rich in RNA. The respective nuclei of these cells differ from each other morphologically and physiologically. The nucleolus in the vegetative nucleus is usually larger than that in the generative nucleus. The vegetative nucleus contains lower amounts of DNA, but its protein content increases after mitosis to about twice that of the generative nucleus.
The protein of the vegetative nucleus is more acidic in nature. The structure of the nucleus in vegetative cell resembles a resting nucleus and it does not normally divide. The generative nucleus is small but contains a higher amount of DNA. It may divide in the pollen grain itself or in the pollen tube to form two sperm nuclei. The pollen grains have reserve food in the form of carbohydrates, proteins and lipids. It appears that the nature of the reserve material in the pollen depends on the mode of pollination. Entomophilous pollen is rich in lipids and anemophilous pollen has mostly starch.