A Level Biology Revision Lesson 104:
Gas Exchange - Fish - Counter Current Exchange.
Task 1. Check Where this Lesson fits into your Exam Specification!
Task 2. Watch the Revision Lesson in Full.
Task 3: Download and complete the accompanying counter current exchange principle revision notes and knowledge check Q and A Booklet.
Check Your Spec!
★ AQA A Level Biology Specification Reference: - 3.3.2 Gas exchange across the gills of fish (gill lamellae and filaments including the counter-current principle).
★ CIE A Level Biology Specification Reference: - N/A
★ Edexcel A Level Biology (Biology A – Salters-Nuffield) Specification Reference: - None Specific but useful for 1.1 Understand why many animals have a heart and circulation (mass transport to overcome limitations of diffusion in meeting the requirements of organisms). 2.1 i) Know the properties of gas exchange surfaces in living organisms (large surface area to volume ratio, thickness of surface, difference in concentration).
★ Edexcel A Level Biology (Biology B) Specification Reference: - Topic 4: Exchange and Transport: ii Understand why organisms need a mass transport system and specialised gas exchange surfaces as they increase in size. 4.3 Gas exchange: Understand how fish are adapted for gas exchange.
★ OCR A Level Biology (Biology A) Specification Reference: -
Module 3: Exchange and transport: In this module, learners study the structure and
function of gas exchange and transport systems in a range of animals and in terrestrial plants. Ventilation and gas exchange systems in mammals, bony fish and insects are used as examples of the properties and functions of exchange surfaces in animals. Learners should be able to demonstrate and apply their knowledge and understanding of: (f) the mechanisms of ventilation and gas exchange in bony fish bony fish – changes in volume of the buccal cavity and the functions of the operculum, gill filaments and gill lamellae (gill plates); countercurrent flow.
★ OCR A Level Biology (Biology B) Specification Reference: -N/A
★ WJEC A Level Biology Specification Reference: -Component 3: REQUIREMENTS FOR LIFE: (d) the common features of the specialised respiratory surfaces of larger animals and the adaptation of respiratory surfaces to environmental conditions - fish have gills for aquatic environments and mammals have lungs for terrestrial environments. (f) ventilation in bony fish and comparison of counter current flow with parallel flow.