Are the different types of plastids interchangeable? If yes,give examples where they are getting converted from one type to another.

(N/A) Yes,plastids are interchangeable and can be converted from one form to another based on the physiological requirements of the plant cell.
$(i)$ In $Capsicum$ (chilli),the ovary is initially green (containing chloroplasts),but as the fruit ripens,the chloroplasts are converted into chromoplasts,giving the fruit its red color.
$(ii)$ In potato tubers,leucoplasts (colourless plastids) are present underground. When these tubers are exposed to sunlight,they develop chlorophyll and are converted into chloroplasts,turning the skin green.
$(iii)$ During the ripening of fruits like tomatoes,chloroplasts (green) are converted into chromoplasts (red/orange) due to the synthesis of carotenoids and the breakdown of chlorophyll.