Practice B - Form and Function with authentic IB Biology exam questions for both SL and HL students. This question bank mirrors Paper 1A, 1B, 2 structure, covering key topics like cell biology, genetics, and ecology. Get instant solutions, detailed explanations, and build exam confidence with questions in the style of IB examiners.
Based on the movements shown in the diagram, what immediate effect will this have on the intrathoracic pressure and air movement?

Red blood cells are smaller and more flexible than most other cells. Which of the following is a reason for its structure?
A student measures their pulse at 72 beats in one minute using their wrist. Which of the following is a method could be used to validate this result?
Which of the following was most essential for scientists to begin studying individual organelle function?
A fossil skull shows large, flat molars and reduced canines. What can be inferred about its diet?
What is the function of aquaporins in membranes?
As multicellular animals grow larger, which challenge most affects their ability to rely on simple diffusion for gas exchange?
Which of the following is a peripheral protein most likely to be found?
Which combination of structural features allows xylem to withstand tension and enable efficient water flow?
During digestion, how is a water molecule used to break down polymers into monomers?