Question:- What
are chloroplasts?
Answer:- The main sites of
photosynthesis in a plant leaf are small cell organelles called chloroplasts or
plastids. Chloroplast is basically a sac like structure containing chlorophyll pigment. Chloroplast can be seen just
below the upper epidermis in a tissue, called the palisade. Chloroplasts are usually
spherical or ovoid vesicles bounded by an envelope of two membranes and filled
with a fluid matrix or stroma. In the stroma of chloroplast
many flattened, ovoid sacs called thylakoids
are present. At places thylakoids are closely packed on one another to form
stacks of discs called grana (singular
granum). The thylakoids of one granum are connected to the thylakoids of
another granum through stromal lamellae.
