Where are plastids seen ? Explain its type and functions in short.
$\Rightarrow$ Plastids are found in all plant cells and in euglenoides.
$\Rightarrow$ 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 : The chloroplasts contain chlorophyll and carotenoid pigments which are responsible for trapping light energy essential for photosynthesis.
$(b) $ Chromoplasts : In the chromoplasts fat soluble carotenoid pigments like carotene, xanthophylls and others are present. This gives the part of the plant a yellow, orange or red colour.
$(c) $ Leucoplasts : The leucoplasts are the 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.
The $DNA$ present in chloroplast is:
What are plasmids ? Describe their role in bacteria ?
The given diagram shows the sectional view of a mitochondrion.
Identify the parts labelled as $A , B , C , D\; \& \; E$