2.2.3 Blood

• Platelets in blood help fight infection.

  False
• Why do larger organisms have a lower surface area to volume ratio?

  Their body volume increases faster than surface area
• What is the primary function of red blood cells?

  Carry oxygen
• What is the typical blood volume of a small mouse?

  2-3 mL
• Blood is responsible for transporting oxygen, nutrients, waste products, and hormones
• In large organisms, oxygen delivery relies on active transport with the protein called hemoglobin
• Platelets (thrombocytes) are essential for blood clotting.


  True
• What is a major challenge in oxygen transport in larger organisms?

  Increased distance
• What protein do larger organisms use to actively transport oxygen?

  Hemoglobin
• Blood transports oxygen, nutrients, and waste products around the body via the circulatory system
• Compare the features of circulatory systems in small and large organisms:

  1️⃣ Small organisms rely on simple diffusion for oxygen delivery.

  2️⃣ Larger organisms use active transport with hemoglobin for oxygen delivery.

  3️⃣ Small organisms remove waste by diffusion to the environment.

  4️⃣ Larger organisms use kidneys and liver to filter waste from blood.
• The kidneys and liver in larger organisms filter waste from the blood.


  True
• Platelets help the blood clot to stop bleeding
• What type of tissue is blood classified as?

  Fluid connective tissue
• What type of circulatory system do small organisms typically have?

  Simple diffusion
• White blood cells (leukocytes) defend the body against infection and disease
• Arrange the following organisms by their typical blood volume from lowest to highest:

  1️⃣ Small Mouse

  2️⃣ Medium Cat

  3️⃣ Large Horse
• Hemoglobin is unnecessary for oxygen transport in smaller organisms.


  True
• What type of tissue is blood classified as?

  Fluid connective tissue
• What two factors does blood regulation help maintain in the body?

  Body temperature and pH balance
• Larger organisms have a complex circulatory system with a heart and vessels
• Match the blood component with its function:

  Red Blood Cells ↔️ Carry oxygen

  White Blood Cells ↔️ Fight infection

  Platelets ↔️ Help blood clot

  Plasma ↔️ Transport cells and substances
• Arrange the functions of blood in the correct order:

  1️⃣ Transport oxygen and nutrients

  2️⃣ Defend against infections

  3️⃣ Maintain body temperature

  4️⃣ Regulate pH balance
• Larger organisms require more efficient circulatory systems than smaller organisms due to metabolic demands.


  True
• What is the primary function of red blood cells (erythrocytes)?

  Carry oxygen
• What is the liquid portion of blood called?

  Plasma
• Efficient oxygen transport in larger organisms requires hemoglobin and a complex circulatory system