3.1

• Specialised Exchange Surfaces have special features to improve their efficiency
• Root Hair Cells

  Cells on plant roots that grow in long chains with microscopic hair covering each branch, providing a large surface area for absorption of water
• Example of specialised exchange surface: Fish Gills
• Alveoli

  • Have a good blood supply and/or ventilation
• Example of specialised exchange surface: Alveoli
• Blood constantly takes oxygen away from the alveoli and brings carbon dioxide


  Helps in gas exchange
• Fish Gills


  • Contain a large network of capillaries, well-ventilated by fresh water passing over them
• Alveoli

  Made from a single layer of thin cells called the alveolar epithelium, allowing for efficient gas exchange
• Exam Question: Give two ways in which the alveoli are adapted for efficient gas exchange
• Most Exchange Surfaces have a large surface area


  • Helps to increase the rate of absorption of water and allows for active transport
• Exam Question: Suggest how microvilli increase the efficiency of nutrient absorption in the small intestine
• Fish gills maintain a concentration gradient of oxygen


  Increases the rate of oxygen diffusion into the blood
• Lungs are ventilated by breathing in and out


  Helps maintain concentration gradients of oxygen and carbon dioxide
• Root Hair Cells

  • Thin structure
• Warm-Up Question: How do the surface area to volume ratios of large and small organisms differ?
• Alveoli are surrounded by a large capillary network


  Giving each alveolus its own blood supply
• Fish Gills

  Gas exchange surface in fish where oxygen and carbon dioxide are exchanged between the fish's blood and the surrounding water
• The Gaseous Exchange System in Mammals
• Describe the distribution of smooth muscle in the marakan gs change y
• The Different Parts are Found in Different Places in the System
• How micrevilli increase the efficiency of sariat absorption in the small intestine

  Not provided
• Describe the distribution of ciliated epithelium in the marmalan gas exchange sykm
• Micrevill are tine ceeasian of the plan ma
• What is the function of goblet call in the maremalian gas exchange
• Module 3: Section 1-Exchange and Transport
• The stadest is given two tissae reples. One was taken from one of the smallest bronchioles and cee was taken from a larger issonchiole. The stadest looks at each sungle under the microscope. Sugged one way in which the stadest will be able to tell the two samples apart
• When you've just gue to the end of a page, but it would be a petty smart idea to have another look at diffusion de page 54
• There's a fair bit to leam on these two pages. Copying out my beaunfal bive table will ap- and then you can write what the function of each part is You won't be coughing and spluttering in the esan once you know this for Module 3: Section 1-Exchange and Transport
• Warm-Up Questions
• Smoking destroys the elastic fibees in the walls of the alveek. Suggest and explain what effect this will have on the process of breaking out
• Cells in the wall of the small intestine are covered in ricvili
• Aest is observing a dissection of a pig's kans. The student is given the pig's trachea, a broachan and a larger breechinle. Apent from the differences in size, plain how the stadme will be able to tell the traches, bronchan and breedice apan ced cland cland
• All can think about at the moment is cube hippos
• Smoking also dostroys cilis in the gaseos exchange sydan. Suggest two problems this could case
• Exam Questions
• Rings of cartilage-I prefer mine in gold.... with diamonds....
• In Mammals, the Lungs are Exchange Organs
• Marginal utility

  The additional utility (satisfaction) gained from the consumption of an additional product
• Producers act rationally by

  Selling goods/services in a way that maximises their profits
• Workers act rationally by

  Balancing welfare at work with consideration of both pay and benefits