Cell Differentiation and Organisation
Multicellular organisms are made up from many different types of cells. All these cells are specialised (designed to carry out specific functions). The process of becoming specialised is called cell differentiation.
The squamous epithelium cells are found in many places, they line the alveoli. Theyre thin and dont have much cytoplasm to have a thin/short diffusion pathway.
Palisade mesophyll cells are found in leaves where photosynthesis occurs. They contain many chloroplasts to absorb lots of light and are thin so carbon dioxide can enter easier.
Similar cells are ogranised into tissues. The squamous epithelium tissue is a single layer of cells.
Phloem tissue, transports sugars around the plants.
Xylem Tissue, Transports water around the plants and provides support.
Tissues are organised into organs, an organ is a group of tissues working together. For example the leaf - Lower epidermis (stomata for gas exhcange), Spongy mesophyll (spaces for gases), Palisade mesophyll (photosynthesis), xylem, phloem and the upper epidermis (waxy waterproof cuticle to reduce water loss). OR the lungs - Squamous epithelium tissue (surrounds the alveoli), Fibrous connective tissue - help force air back out and blood vessels (capillaries surround the alveoli).
Organs are organised into systems.
The circulatory system - the heart and blood vessels.
The respiratory system - the lungs, the trachea, the bronchi.
The shoot system - leaves, buds, stem and flowers.