Question
Question: The Grana and Stroma are the parts of which cell organelles A. Mitochondria B. Chloroplast C. ...
The Grana and Stroma are the parts of which cell organelles
A. Mitochondria
B. Chloroplast
C. Ribosome
D. Golgi body
Solution
Hint: The grana and stroma are the parts of the cell organelle which is also known as the kitchen of the cell and is a semi-autonomous cell organelle like mitochondria found in plant cells.
Complete answer:
The grana and stroma are present inside the cell organelle chloroplast. It is a type of plastid. It is a double membraned cell organelle.
Additional Information:
Chloroplast has the following feature:
- The chloroplast contains three parts: the envelope, stroma, and the lamellar system.
- It is also known as the autoplast and the photosynthetic apparatus.
- Envelope: The envelope is a double membrane structure, the outer membrane is freely permeable but the inner membrane has shown selective permeability.
- Stroma or Matrix: Proteinaceous and consists of double-stranded circular DNA known as plastidome. The enzyme RUBISCO, which is also the most abundant enzyme on earth, is present in the stroma of the chloroplast.
- Lamellar System: It consists of thylakoids which are also double membrane-bound structures. They are also known as Baggy Trousers. Thylakoids are considered as the structural units of the chloroplast. 2-7 thylakoids are stacked together to form a structure known as grana. In-plant cells each chloroplast has a total of 40-60 grana but these are absent in the chloroplast of algae and bundle sheath cells of C4 plants.
- The inner membrane contains light-harvesting units known as quantasomes. These structures take part in photosynthetic reactions.
So, the correct answer is, ‘chloroplast’.
Note:
Chloroplasts are known as Semi-autonomous cell organelles because they have the following two features:
They possess their own DNA, RNA, and ribosomes.
They also possess their protein-synthesizing machinery.
A chloroplast can be of a variety of shapes. In Chlamydomonas it is cup-shaped, in ulothrix it is girdle shaped, the spiral-shaped chloroplast is seen in spirogyra, and discoidal chloroplast is seen in higher plants.