The dicotyledonous leaf shows which of the following venation? A Parallel B Palmate C Pinnate parallel D Reticulate
Hint: Veins are composed of xylem and phloem cells or vascular bundles. xylem transports water from the petiole throughout the lamina cells and the phloem transports sugars prepared through photosynthesis out of the leaf to the rest of the plant. Veins are spread all over the leaves in various patterns so they can easily transport water and glucose to all the cells like parenchyma, sclerenchyma, and mesophylls of leaves. Venation is the arrangement of veins in the lamina of the leaf. Two types of venation are present. They are reticulate venation and parallel venation.
Complete answer: Option A: Parallel. This type of venation is usually seen in monocot plants and not in dicot plants. In this type of venation, the veins and veinlets run parallel to each other in the leaf lamina. Example: Banana, coconut, Maize. Option A is not correct. Option B: Palmate. Palmate venation is a type of parallel venation seen in monocots and not in dicots. In this type of venation, veins radiate out from the base of the leaf just like fingers spread out from the palm of a hand, hence the name palmate. Option B is not correct. Option C: Pinnate parallel. Pinnate parallel venation is a type of parallel venation seen in monocots and not in dicots. In this type of venation, there is a prominent center vein, or mid-rib with other veins branching off from the middle. Option C is not correct. Option D: Reticulate. In this type of venation, the veins are interconnected to form a web-like network. This network makes it easier for the transport of water and minerals. It is usually seen in dicot plants. Example: Teak, tulsi, papaya, mango etc. Option D is correct.
Hence, Option D is the correct answer.
Note: Reticulate venation is characterized by an irregular vein structure that forms a network. Hibiscus, papaya, Tulsi leaves, coriander, China Rose, and Mangifera are some examples. Reticulate venation is found in dicot plants, while parallel venation is found in monocot plants, and it is an important characteristic for distinguishing monocots from dicots.