Which of the following is a primary function of blood in the human body?

• A. Generating electrical impulses for muscle contraction
• B. Storing calcium for bone strength
• C. Producing hormones for growth
• D. Transporting oxygen and nutrients to cells

Answer: (D)

Verified step by step guidance

1. Understand the primary functions of blood in the human body. Blood is a vital fluid that performs several key roles essential for maintaining homeostasis.
2. Recognize that one of the main functions of blood is to transport substances throughout the body. This includes the delivery of oxygen from the lungs to the cells and the transport of nutrients absorbed from the digestive tract to various tissues.
3. Consider the role of red blood cells, which contain hemoglobin, a protein that binds oxygen in the lungs and releases it in tissues where it is needed for cellular respiration.
4. Acknowledge that blood also carries waste products away from cells to be excreted, such as carbon dioxide to the lungs and urea to the kidneys.
5. Conclude that while blood has many functions, the primary function relevant to this question is the transportation of oxygen and nutrients to cells, which is crucial for sustaining life and supporting cellular activities.