This book details material needed for the IGCSE and GSCE examinations in the UK. For US customers this is up to the age of 16 in the UK education system.
The book uses all of the features of the interactive textbook and will help a student to understand the organs involved in excretion in animals and plants.
This current edition is free as it is not practicable to obtain ISBNs for sole author texts as yet, and I am not registering with the IRS as I am a UK citizen not a US citizen.