Q.Distinguish the anatomy of dicot stem from monocot stem.

Step 1. Hypodermis. A dicot stem's hypodermis is collenchymatous, giving mechanical support while the stem is still elongating. A monocot stem's hypodermis is sclerenchymatous, since it is laid down once with no ongoing elongation to accommodate.

Step 2. Ground tissue and pith. A dicot stem's ground tissue is differentiated into distinct cortex, endodermis, pericycle and pith zones. A monocot stem's ground tissue is not differentiated at all - it remains a single continuous mass of parenchyma from the hypodermis to the centre.

Step 3. Starch sheath. A dicot stem's innermost cortical layer is present as a starch sheath (its endodermis-equivalent, rich in starch grains). A monocot stem, having no differentiated cortex/endodermis, has no starch sheath.

Step 4. Medullary rays. A dicot stem has medullary rays - the interfascicular parenchyma separating its ring of vascular bundles. A monocot stem, whose bundles are scattered rather than ring-arranged, has no medullary rays. …

Work through the five standard comparison points - hypodermis type, ground tissue differentiation, starch sheath, medullary rays, and vascular bundle t …

• Describing the vascular bundle difference (open/ring vs closed/scattered) but omitting the ground-tissue differentiation difference, which is just as fundamental. …