The following puzzle is designed to check the student's understanding of the work on respiration.

To complete the grid, they have to select the answer they think is correct. If they are correct, they move on to another question and continue until they come to the end of the grid.

There are ten questions.

If they answer incorrectly they return to the question to have another try and this continues until they select the correct answer.

There are opportunities to return to main pages throughout the exercise.