Question

Write one similarity between Plastid and mitochondria.

Answer 1

Hint: Plastids and Mitochondria are cell organelles. These are found in plant cells. Both are similar with respect to their dependency on the nucleus (brain) of the cell.

Complete answer:
Plastids are small organelles present in the cytoplasm of the cell. These contain stored food or pigments. These are of three types.
a) Chromoplasts: These contain colored pigments and are seen in flowers, fruits, ageing leaves, etc.
b) Chloroplasts: These contain green pigments that help in the process of photosynthesis.
c) Leucoplasts: These store food. These are seen in non green parts like roots.
Structure of Plastids show two membranes. These are outer and inner membranes. Thus Plastids are double membraned structures. Matrix is the ground substance that shows presence of pigments and DNA and ribosome.

Mitochondria are also cell organelles in the cytoplasm. These are known as 'power houses of the cell'. The structure consists of outer and inner membranes. The inner membrane is folded into finger-like projections called cristae. The matrix shows presence of DNA and ribosome.Thus we can see that both the organelles are double membraned-structures but the inner membrane is folded into a cristae in Mitochondria and not in Plastids. hence only the outer membrane is the same.
The matrix contains DNA and ribosome in both the organelles.
Thus Plastids and Mitochondria are known as Semi-Autonomous structures.

Semi-autonomous structures means these organelles can replicate on their own due to the presence of their own DNA. However, these organelles are still dependent on the nucleus for their other functions. Thus these are 'semi' meaning half and 'autonomous' means on its own.

Note: Mitochondria are seen in both plant and animal cells but Plastids are seen only in plant cells.They are known as “powerhouse of the cell”.