Explanation

• Blood is red because of a protein called hemoglobin inside our red blood cells,
• Which contains iron that changes color when it binds to oxygen

Last updated by NS on 5-09-2026

Explanation

• The mitochondrion is the primary site of oxidative phosphorylation in eukaryotic cells.
• Oxidative phosphorylation occurs mainly across the inner mitochondrial membrane.
• It produces most of the cell’s ATP (energy) through the electron transport chain and ATP synthase.

Last verified on 05-09-2026

Explanation

• The lungs exchange gases — they absorb oxygen (O₂) and release carbon dioxide (CO₂).
• This process is essential for respiration and energy production in the body.

Last verified on 05-09-2026

Explanation

• The pituitary gland is located at the base of the brain.
• It is below the hypothalamus.
• It sits in a hollowed-out area of the sphenoid bone called the sella turcica.

Last verified on 05-09-2026

Explanation

• The liver is the largest gland in the human body.
• It is situated in the right upper quadrant of the abdomen, beneath the diaphragm, and above the stomach.
• It is reddish-brown.
• It is weighs approximately 1.5 kg.

• The pineal gland is the smallest gland.
• It about the size of a grain of rice.
• It weighs approximately 150 mg.
• It is part of the endocrine system.