Exchanging Materials

Question 1

What Happens when Living Organisms Get Bigger and Ore Complex?

Answer 1

• Gases and Food Molecules can No Longer Reach Every Cell Inside the Organisms by Simple Diffusion.
• Metabolic Waste can’t be Removed Fast Enough to Avoid Poisoning the Cells.

Question 2

Adaptations to Make the Process of Exchange More Efficient?

Answer 2

• Having a Large Surface Area over Which Exchange can Take Place.
• Having a Thin Membrane or Being Thin to Provide a Short Diffusion Path.
• In Animals, Having an Efficient Blood Supply Moves the Diffusing Substances Away From the Exchange Surfaces.
• In Animals, Being Ventilated Makes Gas Exchange More Efficient by Maintaining Steep Concentration Gradients.

Question 3

Human Surface Area to Volume Ratio is so ______ that the Cells Inside Your Body can’t Possibly to get the Food and Oxygen they Need, or Get Rid of _________ they Produce, by Simple Diffusion.

Answer 3

Low…Waste…

Question 4

Air is Moved Into and Out of Your Lungs when you Breathe, Ventilating the Millions of Tiny Air Sacs Called __________. These have an Enormous Surface Area and a Rich Blood Supply for Effective _____ Exchange.

Answer 4

Alveoli…Gas…