Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Blood consists of four main components: red blood cells, white blood cells, platelets, and plasma.
Red blood cells (erythrocytes) are specialized for oxygen transport. They contain the protein hemoglobin (), lack a nucleus to maximize space for , and have a biconcave shape to increase the surface area to volume ratio for faster diffusion.
White blood cells are part of the immune system. Phagocytes have a lobed nucleus and engulf pathogens via phagocytosis. Lymphocytes produce specific antibodies that bind to antigens on the surface of pathogens.
Platelets are small fragments of cells that trigger the process of blood clotting to prevent blood loss and the entry of pathogens into the body.
Plasma is the yellowish liquid that transports dissolved substances, including carbon dioxide (mostly as ), urea, hormones, heat energy, and nutrients such as glucose and amino acids.
📐Formulae
💡Examples
Problem 1:
Explain why the biconcave shape of a red blood cell is an advantage for the transport of .
Solution:
The biconcave shape increases the surface area to volume () ratio.
Explanation:
A higher ratio allows oxygen () to diffuse into and out of the cell more rapidly, ensuring efficient loading in the lungs and unloading in the tissues.
Problem 2:
Contrast the functions of phagocytes and lymphocytes in the blood.
Solution:
Phagocytes engulf pathogens; Lymphocytes produce antibodies.
Explanation:
Phagocytes provide a non-specific response by digesting pathogens through phagocytosis. Lymphocytes provide a specific immune response by secreting antibodies that are complementary to specific antigens.
Problem 3:
List four substances transported in the blood plasma.
Solution:
, glucose, urea, and hormones.
Explanation:
Plasma acts as a solvent for various solutes: is a waste product of respiration, glucose is a nutrient, urea is an excretory product from the liver, and hormones are chemical messengers.