Human Physiology and Anatomy

Hemoglobin is a protein in red blood cells that binds to oxygen in the lungs and transports it to tissues throughout the body. Each hemoglobin molecule can carry four oxygen molecules. The other options are incorrect - hemoglobin does not destroy bacteria (white blood cells do), prevent anemia (it causes anemia when deficient), or utilize energy directly.

The kidney's primary function is filtering blood to remove waste products and excess substances, excreting them as urine. Each kidney contains about one million nephrons that perform this filtration. While kidneys also help regulate blood pressure and produce hormones, waste removal is their MAIN function. The other options describe functions of other systems (circulatory, nervous, digestive).

The kidney's primary function is filtering blood and removing metabolic waste products like urea, creatinine, and excess salts through urine formation. While kidneys do help regulate blood pressure (via renin-angiotensin system), this is not their main function. Temperature regulation is managed by the skin and hypothalamus, and digestion involves the gastrointestinal tract.

Haemoglobin is a protein in red blood cells that binds to oxygen in the lungs and carries it to tissues throughout the body. Each haemoglobin molecule can carry up to four oxygen molecules.

The respiratory system performs multiple vital functions. Ventilation moves air in and out of lungs. Gas exchange transfers oxygen into blood and removes carbon dioxide. The system also eliminates water vapor and helps regulate blood pH by controlling carbon dioxide levels.

The kidney's primary function is filtering blood and removing waste products like urea, creatinine, and excess salts through urine. It does regulate blood pressure indirectly, but waste removal is its main role.

Hemoglobin is the red pigment in red blood cells that binds to oxygen in the lungs and transports it to body tissues. It does not destroy bacteria, prevent anemia, or directly utilize energy.

The plasma membrane (cell membrane) primarily regulates the transport of materials in and out of the cell through selective permeability. It does not control all cellular activities (that's the nucleus), store materials (that's vacuoles), or maintain shape alone (that's the cell wall in plants).

The gallbladder's primary function is to collect and store bile produced by the liver. It does NOT produce bile (that's the liver's job), filter calcium (that's kidneys), or filter toxins (that's the liver). The gallbladder concentrates and stores bile for release during digestion.

Finger ridges evolved to enhance friction and grip. They function like tire treads, helping us grasp objects securely by increasing surface area and providing mechanical advantage. The other functions listed are incidental benefits, not the primary evolutionary purpose.

Hemoglobin is the iron-containing protein in red blood cells responsible for transporting oxygen from the lungs to body tissues and returning carbon dioxide. While it contains iron, its primary function is oxygen transport, not iron utilization per se. Bacteria destruction and anemia prevention are not its direct functions.

The primary function of kidneys is to filter blood and remove waste products and excess substances from the body, producing urine. While kidneys do help regulate blood pressure indirectly through the renin-angiotensin system, their main purpose is waste removal and filtration, not blood pressure control directly.

Hemoglobin is the iron-containing protein in red blood cells responsible for carrying oxygen from the lungs to body tissues and returning carbon dioxide. This oxygen transport function is essential for cellular respiration. Hemoglobin does not directly prevent or cause anemia - it's the molecule whose deficiency causes anemia.

Ligaments are tough, fibrous connective tissues that connect bones to other bones at joints, providing stability and limiting excessive movement. They are different from tendons, which connect muscles to bones. Option A is incorrect because muscles connect to bones via tendons, not ligaments.

Tendons connect muscles to bones, transmitting muscle contractions to bones to create movement. They are different from ligaments, which connect bones to other bones. Option B is incorrect because tendons do not connect bones directly to each other.