Question

Julius von Sachs observed that

• A. When leaves are kept in darkness, they retained starch
• B. When leaves are kept in darkness, they consumed starch
• C. When leaves are exposed to sunlight, they produced starch
• D. When leaves are exposed to sunlight, they consumed starch

Answer 1

Answer: (B), (C)

When leaves are exposed to sunlight, they produced starch

Julius von Sachs demonstrated in the beginning of 1861, that plants produced starch by the assimilation of Carbon dioxide. He showed that the assimilation occurs in the chloroplasts, which contain the chlorophyll pigment molecules.
He observed that if a leaf containg starch is kept in darkness for a while, the starch disappears and if the same leaf is exposed to sunlight, the starch reappears in chloroplasts.