AP BIOLOGY

Detailed explanation-1: -A leaf is often organized with one main vein running down the middle of the blade. This vein is called the midrib. All of the veins, the petiole, and the midrib help position the blade so that it is facing the light source.

Detailed explanation-2: -Midrib is the thickest vein present in the middle of the leaf. It separates the lamina or leaf blade into 2 parts. Smaller veins are observed radiating from the midrib.

Detailed explanation-3: -The central, thick, linear vein that runs along the length of a leaf is called midrib.

Detailed explanation-4: -∙ The leaf lamina consists of a midrib, veins and veinlets arranged in the form of a network. ∙ The lines or branches arising from the midrib in leaf are known as veins. ∙ The long vein present in the middle of the lamina is known as midrib.

Detailed explanation-5: -Mesophyll: This forms the middle layer of the leaf. It is differentiated into two layers depending on the type of cells found: palisade and spongy mesophyll layers. It is in this layer that the chloroplasts are found. Chloroplasts are cell organelles that contain chlorophyll which is required for photosynthesis.