Circulation & Gas Exchange

Why do medium to large-sized multicellular organisms need specialized systems for gas exchange?

• Their cells are in direct contact with the environment

• They do not need to exchange gases

• Their cells are not in direct contact with the environment

• They can rely on simple diffusion

What adaptation helps Weddell seals reduce respiratory oxygen consumption?

• Increased lung capacity

• Reduced heart rate

• High levels of myoglobin

• Large blood volume

In vertebrates, what is the function of the capillaries in the systemic circuit?

• To receive O₂ from the environment

• To supply O₂ to the interstitial fluid

• To pump blood through the heart

• To mix blood with interstitial fluid

What does carbonic acid rapidly dissociate into?

• H₂ & CO₂

• H₂O & CO₂

• H⁺ & HCO₃⁻

• O₂ & H₂O

Which of the following components are found in interstitial fluid?

• Salts, hormones, gases

• Proteins, lipids, carbohydrates

• Enzymes, vitamins, minerals

• Nucleic acids, amino acids, glucose

What type of heart do fish have?

• Two-chambered heart

• Three-chambered heart

• Four-chambered heart

• Single-chambered heart

What are the three ways to transport CO₂ in the blood?

• CO₂ bound to hemoglobin, HCO₃⁻ dissolved in plasma, CO₂ dissolved in plasma

• CO₂ bound to hemoglobin, HCO₃⁻ bound to hemoglobin, CO₂ dissolved in plasma

• CO₂ bound to hemoglobin, HCO₃⁻ dissolved in plasma, CO₂ bound to plasma proteins

• CO₂ bound to hemoglobin, HCO₃⁻ bound to plasma proteins, CO₂ dissolved in plasma

What is the function of ostia in the hearts of organisms with an open circulatory system?

• To pump hemolymph out of the heart

• To draw hemolymph into the heart

• To oxygenate the hemolymph

• To filter waste from the hemolymph

What is one advantage of the closed circulatory system in birds and mammals compared to amphibians?

• Mixing of oxygenated and deoxygenated blood

• Lower blood pressure

• Better delivery to all tissues

• Single pump system

What is a characteristic of mature RBCs in mammals?

• They have nuclei and organelles

• They lack nuclei and organelles

• They are larger than 10 µm in diameter

• They are involved in immune response