Question

Grana are the stacks of _________ membranes.

Answer 1

Hint: Grana are the parts of the chloroplast. Chloroplasts are the cell organelles that are present in the plants and algae.

Complete answer:
Grana:
1.The thylakoids of the chloroplast form stacks of disks which are called the grana (singular – granum).
2.One thylakoid stack is called a granum.
3.Thylakoids consist of the thylakoid membranes which surround a thylakoid lumen.
4.Thylakoids are the membrane bound compartments found inside the chloroplasts.
5.Thylakoids are the site where light dependent reactions of photosynthesis take place.
6.Grana are connected by the stroma lamellae.
7.The intergranal thylakoids join granum stacks together as a single functional component.
 8.The grana resembles the stacks of pancakes and are not uniform.

Additional information:
Chloroplasts – Chloroplasts are the organelles that are found in the green leaves and green stems of the plant. The green colour of the plant leaves and stem is due to the pigment chlorophyll. Chlorophyll converts the energy of Sunlight and stores it in the form of energy rich molecules that are ATP and NADPH. Then ATP and NADPH are used to make organic food materials. Chloroplasts also synthesise fatty acids, amino acids and it also helps in the immune response of the plants.

Therefore, it has been clear from the above discussion that grana are the stacks of thylakoid membrane.

Note: The chloroplast organelles help in conducting the process of photosynthesis (the process by which plants make their own food with the help of water, carbon dioxide and sunlight). Chloroplasts have the photosynthetic pigments called chlorophyll that capture the energy from sunlight.