Question

Kranz anatomy is found in
(a)Stems of ${C}_{4}$ plants
(b)Stems of ${C}_{3}$ plants
(c)Leaves of ${C}_{4}$ plants
(d)Leaves of ${C}_{3}$ plants

Answer 1

Hint: The word Kranz means “wreath” or “ring”. Kranz anatomy is a specialized structure in some sort of plants where the mesophyll cells are clustered round the bundle-sheath cells during a ring-like fashion.

Complete answer:
Kranz anatomy is a special structure within the leaves of plants that have a ${C}_{4}$ pathway of carbon dioxide fixation. The leaves have a hoop of mesophyll cells, which includes a couple of little chloroplasts concerned with the initial fixing of carbon dioxide, enclosed a sheath of parenchyma cells (the bundle sheath) which has big chloroplasts involved within the Calvin cycle. ${C}_{4}$ photosynthesis is found in many plant species, mostly in monocots (such as maize, sugar cane and a number of other grasses) but also in many dicots (such as amaranth and flaveria).

Additional Information:
${C}_{4}$ photosynthesis includes novel leaf anatomy, metabolic specializations, and modified gene expression. Plants that use this pathway basically have a particular Kranz leaf anatomy, consisting of two photosynthetic cell types. Their vascular bundles are enclosed by two rings of cells; the inner ring, known as bundle sheath cells, includes starch-rich chloroplasts lacking grana, which differ from those in mesophyll cells present as the outer ring. This structural framework permits for the categorization and functional separation of two sets of carboxylation and decarboxylation reactions.
So, the correct answer is ‘Leaves of ${C}_{4}$ plants’.

Note: The light-dependent reactions and the Calvin cycle are separated in the ${C}_{4}$ plants. The Calvin cycle takes place in the bundle-sheath cells and the light-dependent reactions take place in the mesophyll cells. In ${C}_{4}$ grasses like maize, the mesophyll cells enclose the bundle sheath cells, and the bundle sheath cells surround the veins.