Stomata are found in the epidermis of leaves and some stems. They are the main route through which gas exchange occurs in plants.
-highly specialised epidermal cells bordering the stomata. Stomatas are open when guard cells are turgid.
Features of effective transport systems
-Large surface areas avaliable for exchanges.
-Control mechanisms that regulate the transport according to need
-A reliable and responsive means of moving the fluid around the body.
Blood circulatory system
-a CLOSED system. Provides for the majority of the animal's transport needs.
Lymphatic drainage system
-an OPEN system. Plays a vital role in maintaining osmotic and fluid balance in tissues, and in immune defences.
-a muscular pump with two pumping chambers (ventricles).
Responsible for moving blood throughout the circulatory system.
Numerous fine channels with thin walls, providing a large surface area across which exchange of substance occurs.
Red Blood cells - White blood cells -Platelets
Produced by cells located in the red bone marrow, found in the upper ends of long bones and in flat bones like the skulls, ribs and pelivis.
Arteries and Veins
Arteries carry blood away from the heart.
Veins carry blood TOWARDS the heart.
Arteries have more muscular walls whereas veins are more easily stretched.
Blood Pressure: Systolic & Diastolic
The higher systolic pressure occurs when the ventricle contracts. The lower diastolic pressure occurs when it relaxes
Supporting fibres. Responsible for the transport of water and minerals from the soil to leaves of plants
Cylindrical skeleton made from the cell walls of dead plant cells joined end to end. Water is drawn through xylem vessels from roots to leaves by transpiration.
-distributes water and materials. Xylem provides water for photosynthesis and to replace water lost continually to the atmosphere by transpiration, and mineral nutrients required as raw materials for the synthesis of organic molecules.
Phloem tissue is involved in the transport of sugars and other organic molecules. In flowering plants, phloem consists of sieve tubes, companion cells and fibres,