Understanding Alveoli and Breathing Experiments

What is the primary function of the alveoli in the lungs?

• To support lung structure

• To produce mucus

• To exchange gases between air and blood

• To filter out dust and particles

Which feature of alveoli helps maintain a steep diffusion gradient?

• Presence of cilia

• Thick walls

• Limited blood supply

• Large surface area

Why is it important to control variables in the exercise and breathing rate experiment?

• To increase the number of participants

• To reduce the time needed for the experiment

• To ensure the results are valid and reliable

• To make the experiment easier to conduct

What is the expected outcome of the exercise on breathing rate experiment?

• Breathing rate decreases with exercise

• Breathing rate remains constant

• Breathing rate increases with exercise

• Breathing rate fluctuates randomly

How does the lime water in the 'huff and puff' experiment indicate the presence of CO2?

• It turns milky

• It changes to blue

• It remains unchanged

• It turns clear