Cell types that make up each tissue and function of each cell type in dicot leaf and they develop in which primary meristem
The dicot leaf is composed of three main tissues: epidermis, mesophyll, and vascular tissue. The cells in each tissue have specific functions and originate from different primary meristems.
1. Epidermis - forms the outermost layer of the leaf and is responsible for protection, water regulation, and gas exchange. The cells in the epidermis include:
- Epidermal cells - flat, non-photosynthetic cells that secrete a waxy cuticle to prevent water loss.
- Stomatal cells - specialized epidermal cells that control gas exchange by regulating the opening and closing of stomata.
- Guard cells - pairs of specialized cells that control the size of the stomatal pore.
The epidermis develops from the protoderm, which is the outermost primary meristem.
2. Mesophyll - forms the bulk of the leaf and is responsible for photosynthesis. The cells in the mesophyll include:
- Palisade mesophyll cells - elongated cells that are tightly packed and oriented vertically to maximize light absorption.
- Spongy mesophyll cells - loosely packed cells that allow for gas exchange and water storage.
The mesophyll develops from the ground meristem, which is the primary meristem that gives rise to all ground tissues.
3. Vascular tissue - provides support, transports water, nutrients, and sugars throughout the plant. The vascular tissue in the leaf includes:
- Xylem - transports water and minerals from the roots to the rest of the plant.
- Phloem - transports sugars and other organic molecules from the leaves to the rest of the plant.
The vascular tissue in the leaf develops from the procambium, which is the primary meristem that gives rise to all vascular tissues.