Where are plastids seen? Explain their types and functions in short.

(N/A) $\Rightarrow$ Plastids are found in all plant cells and in euglenoids.
$\Rightarrow$ These are easily observed under the microscope as they are large. They bear some specific pigments,thus imparting specific colours to the plants.
$\Rightarrow$ Based on the type of pigments,plastids can be classified into three types:
$(a)$ Chloroplasts,$(b)$ Chromoplasts,and $(c)$ Leucoplasts.
$(a)$ Chloroplasts: These contain chlorophyll and carotenoid pigments,which are responsible for trapping light energy essential for photosynthesis.
$(b)$ Chromoplasts: In these,fat-soluble carotenoid pigments like carotene,xanthophylls,and others are present. This gives the plant parts a yellow,orange,or red colour.
$(c)$ Leucoplasts: These are colourless plastids of varied shapes and sizes with stored nutrients:
$(i)$ Amyloplasts: Store carbohydrates (e.g.,potato).
$(ii)$ Elaioplasts: Store oils and fats.
$(iii)$ Aleuroplasts: Store proteins.