Question

The Grana and Stroma are the parts of which cell organelles
A. Mitochondria
B. Chloroplast
C. Ribosome
D. Golgi bodies

Answer 1

The grana comprises a pigment system which includes chlorophyll a, chlorophyll b, xanthophyll and carotene while the stroma consists of all the requisite enzymes needed for carrying out photosynthesis.

Complete answer:
Chloroplasts are the cell organelles present in higher plants. Chloroplasts are the double membranous structures that are bounded by two units of membranes. They consist of a green pigment known as the chlorophyll. These pigments capture the light energy and thus play an important part in photosynthesis.
Chloroplasts contain two distinct regions:
1. Grana, which are the stacks of membrane bound discs like flattened structures known as the thylakoids. Chlorophyll molecules are present in this region and therefore it is also referred to as the major functional unit of chloroplasts.
2. Stroma, on the other hand, is the uniform matrix in which the grana are implanted. Various photosynthetic enzymes are present in the stroma along with the starch granules, ribosomes and DNA.
Moreover, during photosynthesis, light reaction is carried out in granum while the dark reaction is carried out in the stroma.
Other cell organelles like Mitochondria, Ribosomes and Golgi bodies do not contain grana and stroma.

Hence, the correct answer is option (B).

Note: The chloroplast is a double membranous structure consisting of an outer and an inner membrane. An intermediate space which is empty is present in between these two membranes surrounding the chloroplast. In the interior of the chloroplast, granum is present while the stack of thylakoids plus stroma is present which is a homogenous matrix containing dense fluid. A green pigment, chlorophyll is present in the thylakoids which plays an important role in the light reaction of photosynthesis by absorbing the radiant energy from the sun. Granum is embedded within a colorless fluid known as the Stroma where food is formed during dark reactions of photosynthesis.