Organising animals & plants

• The blood, blood vessels, and the heart make up the circulatory system which transports substances to and from the body cells
• Plasma has blood cells suspended in it and transports proteins and other chemicals around the body.
• Red blood cells contain haemoglobin that binds to oxygen to transport it from the lungs to the tissues
• White blood cells help to protect the body against infection.
• Platelets are cell fragments that start the clotting process at wound sites.
• Blood flows around the body in the blood vessels. The main types of blood vessels are arteries, veins, and capillaries.
• Substances diffuse in and out of the blood in the capillaries.
• The valves prevent backflow, ensuring that blood flows in the right direction.
• Human beings have a double circulatory system.
• The heart is an organ that pumps blood around the body.
• Heart valves keep the blood flowing in the right direction.
• Stents can be used to keep narrowed or blocked arteries open.
• Statins reduce cholesterol levels in the blood, reducing the risk of coronary heart disease.
• Damaged heart valves can be replaced using biological or mechanical valves.
• The resting heart rate is controlled by a group of cells in the right atrium that form a natural pacemaker.
• Artificial pacemakers are electrical devices used to correct irregularities in the heart rhythm.
• Artificial hearts are occasionally used to keep patients alive while they wait for a transplant, or for their heart to rest as an aid to recovery.
• The lungs are in your chest cavity, protected by your ribcage and separated from your abdomen by the diaphragm.
• The alveoli provide a very large surface area and a rich supply of blood capillaries. This means gases can diffuse into and out of the blood as efficiently as possible.
• Plant tissues are collections of cells specialised to carry out specific functions.
• The structure of the tissues in plant organs is related to their functions.
• The roots, stem, and leaves form a plant organ system for the transport of substances around the plant.
• Plants have separate transport systems.
• Xylem tissue transports water and mineral ions from the roots to the stems and leaves.
• Phloem tissue transports dissolved sugars from the leaves to the rest of the plant, including the growing regions and storage organs.
• The loss of water vapour from the surface of plant leaves is known as transpiration.
• Water is lost through the stomata, which open to let in carbon dioxide for photosynthesis.
• The stomata and guard cells control gas exchange and water loss.
• Factors that increase the rate of photosynthesis or increase stomatal opening will increase the rate of transpiration. These factors include temperature, humidity, air flow, and light intensity.
• Transpiration is more rapid in hot, dry, windy, or bright conditions.