The reason is to help in seed dispersal. Seed dispersal is the movement or transport of seeds away from the parent plant. Due to the fact that plants have very limited mobility they have to rely upon variety of dispersal; vectors to transport their seeds, including both abiotic and biotic factors. Seed dispersal is important because if seed are not dispersed, many germinating seedlings will grow very close to the parent plant which would result to competition between every one of the seedlings as well as the parent. The competition for essential growth factors such as light, space, water and nutrients.
Chloroplasts are organelles found in plant cells that conduct photosynthesis. Chloroplasts absorb light and use it in conjunction with water and carbon dioxide gas to produce food for the plant.
I'm assuming you meant and frailness not fertility, in which case it is the oldest old period
