Topic 3

Question 1

describe the organisation of gills on fish

Answer 1

4 layers of gills on both sides of the head
the gills are made up of stacks of gill filaments
each gill filament is covered in gill lamellae, positioned at right angles to the filament
this creates a large surface area

Question 2

describe how water moves through a fish

Answer 2

when fish open their mouths water rushes in and over the gills and then out through a hole in the sides of their head