Question

The structures that are formed by stacking of organized flattened membranous sacs in the chloroplasts are?

• A. Cristae
• B. Stroma
• C. Stroma lamellae
• D. Grana

Answer 1

The correct option is D

Grana

The correct option is D.

Explanation of the correct option:

1. Thylakoids, which are organized flattened membrane sacs, are stacked to create grana.
2. Grana are the structures that are created in the chloroplasts by stacking organized flattened membrane sacs (thylakoids).
3. Plant cells contain organelles called chloroplasts that are used for photosynthesis.

Explanation of the incorrect options:

Option A:

1. A mitochondrion's inner membrane fold is known as a crista.
2. The crista is a unique wrinkled shape of the inner membrane, which offers a huge surface area for chemical reactions to take place.
3. The inner membrane is folded into cristae to boost the mitochondrion's ability to produce ATP.
4. These folds enable the mitochondrion to contain many more ATP synthase and electron transport chain enzymes.

Option B:

1. In botany, the term "stroma" refers to the clear liquid that surrounds the grana inside the chloroplast.
2. The stroma contains the grana and the sub-organelles, where photosynthesis begins before the stromal chemical changes are finished.
3. The liquid that fills the inside space of the chloroplasts, which encloses the grana and the thylakoids, is known as the stroma.
4. The stroma is now understood to include chloroplast DNA, starch, and ribosomes in addition to the enzymes required for the Calvin cycle and maintain the pigment thylakoids.

Option C:

1. Thylakoids from two distinct grana are connected by stroma lamellae.
2. By separating grana so they do not clump together, they boost the effectiveness of photosynthesis.
3. They make sure that photosynthesis uses the most amount of solar energy possible.
4. By maintaining grana at a distance from one another so that they do not crowd together, they improve the effectiveness of photosynthesis.

Final answer:
The structures that are formed by stacking of organized flattened membranous sacs in the chloroplasts are grana.