Gas Exchange in Animals and Humans

Gas Exchange in Animals

• Gas exchange occurs in animals, not just plants.
• Practical 7.12 examines carbon dioxide uptake/release in mealworms.
• Materials needed: boiling tubes, forceps, cotton thread, mealworms, measuring cylinder (10 cm³), hydrogencarbonate indicator, plastic vial with small holes, test tube rack.
• Procedure: Add 3 cm³ of hydrogencarbonate indicator to two boiling tubes. Observe initial color. Place mealworms in a vial, put vial in one tube (tube A). Seal both tubes. Observe color change after 1 hour.
• Procedure: Wear gloves when handling mealworms.
• Mealworms release carbon dioxide.
• Practical 7.13 explores oxygen uptake/release in mealworms.
• Different materials. Capillary tubes with color markers, wire gauze, ruler, soda lime, 2 bags, mealworms.
• The experiment shows that mealworms consume oxygen and release carbon dioxide.

Gas Exchange in Humans

• Humans have a specialized breathing system.

• Gas exchange supplies oxygen to body cells, removing carbon dioxide.

• Practical 7.14 compares inhaled and exhaled air:

  • Collect inhaled air and exhaled air in separate jars.
  • Measure how long candles burn in each jar.
  • Inhaled air allows the candle to burn longer.
  • Exhaled air contains less oxygen.

• Practical 7.14 examines oxygen, carbon dioxide, and water vapor content in inhaled vs exhaled air:

  • Hydrogencarbonate indicator: Exhaled air has more CO2. (Changes indicator color).
  • Cobalt chloride paper: Measure water vapor content. (Color change indicates water vapor presence).

Gas Exchange at Air Sacs

• Oxygen and carbon dioxide exchange between air sacs and capillaries.
• Oxygen in inhaled air enters blood in capillaries.
• Blood carries oxygen to body cells.
• Carbon dioxide produced in cells travels to air sacs.
• Exhaled air contains less oxygen, more CO2, more water vapor, and warmer air.

Effects of Smoking

• Smoking damages the respiratory system, reducing gas exchange efficiency.
• Smoking contains over 7000 chemicals. Some damage the body's respiratory system and affect gas exchange.
• Tar deposits in lungs, reducing air sac surface area.
• Carbon monoxide reduces blood's oxygen-carrying ability.
• Chemicals damage air sacs, reducing surface area.
• Smoking causes harmful diseases (stroke, lung cancer, heart disease).

Explore the intricate processes of gas exchange in animals, including experiments involving mealworms. This quiz covers carbon dioxide uptake and oxygen release, as well as the specialized breathing system in humans. Test your knowledge on the materials used and the significance of these processes in living organisms.