Question

All of the following structures are found within a chloroplast except

• A. Thylakoids
• B. Grana
• C. Stroma
• D. Pigments
• E. Cristae

Answer 1

Answer: (E)

Cristae

Chloroplasts are the green coloured plastids which are involved in photosynthesis. The chloroplast is bounded by two membranes, an outer membrane and an inner membrane with an intermembrane space in them. The space enclosed by inner membrane is called stroma. Stroma contains small cylinder like structures called grana. Each granum consists of disc-shaped membranous sacs called thylakoids which are piled one on the top of other. Chloroplast is distinguished into clear compartments : the fret membrane system and the stroma. The membrane system is involved in trapping the light and to carry out light-dependent reactions through the appressed and non-appressed part of the grana in which various light absorbing pigments are found. Hence 'Thylakoids, Grana, Stroma, Pigments' are found within a chloroplast.

Cristae is found within the mitochondrion. The inner membrane of the mitochondrion is thrown into folds and tubules called cristae.

Hence Cristae are not found within the chloroplast.

So, the correct answer is 'Cristae'.