Question

Grana and stroma lamellae are the parts of
A) Mitochondria
B) Chloroplast
C) Endoplasmic reticulum
D) Vacuoles

Answer 1

Hint: Grana are the stack of thylakoid membranes that hold the chlorophyll molecules

Complete answer:
A) Whenever you hear the term ‘grana’, what should come to your mind are stacks of books! This is because granum looks like stacks of books kept one over the other. Just like the books are made of paper and store the information, grana are made up of thylakoid membranes and hold the chlorophyll molecules. Grana are the sites where the light reaction of the photosynthesis is performed.
Well, if something related to photosynthesis is talked about, then it has to be none other than the chloroplast. It is the green plastid that provides the ability to the plants to produce the organic carbon and be the producers.
Apart from the grana, the chloroplast also shows stroma lamellae, again made up of thylakoids. They join the grana together. All the components of the chloroplast are present in a fluid matrix called the stroma. Externally, chloroplast is bounded by a double membrane and additionally has a thylakoid membrane system organised into grana and stroma lamellae.

B) Mitochondria are known for showing finger-like foldings in their inner membrane called cristae.
C) Endoplasmic reticulum is made up of sac-like networks called cisternae and also shows growth of vesicles and tubules.
D) Vacuoles are storing organelles in plant cells primarily. They are surrounded by a membrane called tonoplast.

Therefore, the correct answer is option B.

Note: The photosystem-II complex involved in photosynthesis occurs in the appressed part of the grana while the photosystem-I complex occurs in the non-appressed part of the grana and stroma lamellae. The dark reaction occurs in the stroma of the chloroplast.