A Level students examine fish gills in a practical Biology lesson.
Year 12 Biologists are now learning about gas exchange surfaces in and out of all living things. Beginning with fish, they have been dissecting fish heads to enable them to identify the characteristics of an efficient gas exchange surface.
The girls opened the gill flap of the fish and observed the teeth and tongue and they also examined the external structure of the fish head, establishing the position of the operculum, the mouth and eyes. They then placed the gill in a petri dish of water to observe the respiratory organ in and out of water. What is the function of the gill bar, asked Mr Matanda, and why can fish not survive out of water?
In future lessons, the girls will be moving on to amphibians, insects and earthworms to see if and how their gas exchange surfaces differ and why. They will also examine a pig’s lungs – the closest they can get to that of a human.