Nursing Elites

1. Which blood component is chiefly responsible for clotting?

• A. Platelets
• B. Red blood cells
• C. Antigens
• D. Plasma cells

Correct answer: A

Rationale: The correct answer is A: Platelets. Platelets are small cell fragments in the blood that play a crucial role in clotting. When there is an injury, platelets adhere to the site and release chemicals that help form a clot to prevent excessive bleeding. Red blood cells transport oxygen, antigens are substances that trigger an immune response, and plasma cells are a type of white blood cell involved in producing antibodies, none of which are primarily responsible for clotting.

2. Which molecule is responsible for storing and providing a quick source of energy during short bursts of intense physical activity, such as weightlifting or sprinting?

• A. ATP (Adenosine Triphosphate)
• B. Glucose
• C. Myoglobin
• D. Lactic Acid

Correct answer: A

Rationale: ATP (Adenosine Triphosphate) is the molecule responsible for storing and providing a quick source of energy during short bursts of intense physical activity like weightlifting or sprinting. ATP is broken down to release energy rapidly when muscles need quick, intense efforts. Glucose is a source of energy but must be converted into ATP before it can be used by muscles. Myoglobin is a protein that stores oxygen in muscle cells and does not directly provide energy. Lactic acid is produced during intense exercise but is not the primary molecule responsible for providing quick energy during short bursts of intense physical activities.

3. What type of molecule forms the cell membrane and controls what enters and exits the cell?

• A. Proteins
• B. Carbohydrates
• C. Lipids
• D. Nucleic acids

Correct answer: C

Rationale: The cell membrane is primarily composed of lipids, specifically phospholipids, which form a lipid bilayer. This lipid bilayer controls what enters and exits the cell, providing a barrier that is selectively permeable. While proteins are also important components of the cell membrane and play various roles, lipids are the main structural component responsible for the membrane's permeability and function. Carbohydrates and nucleic acids are not the primary components of the cell membrane and do not have the same structural role as lipids.

4. Which of the following is NOT an element of the respiratory system?

• A. Ribs
• B. Trachea
• C. Diaphragm
• D. Alveoli

Correct answer: A

Rationale: The correct answer is A: Ribs. The ribs are part of the skeletal system, providing structure and protection to the thoracic cavity. The trachea, diaphragm, and alveoli are all essential components of the respiratory system. The trachea carries air to and from the lungs, the diaphragm aids in breathing by contracting and relaxing to change the volume of the thoracic cavity, and the alveoli are tiny air sacs where gas exchange occurs in the lungs. Therefore, ribs do not play a direct role in the respiratory process and are not considered a part of the respiratory system.

5. What is a rod-shaped structure that forms when a single DNA molecule and its associated proteins coil tightly before cell division?

• A. Centromere
• B. Chromatid
• C. Chromosome
• D. Gene

Correct answer: C

Rationale: A chromosome is a rod-shaped structure that forms when a single DNA molecule and its associated proteins coil tightly before cell division. It contains the genetic material and is essential for cell division and replication. The centromere is a specific region of a chromosome that plays a role in cell division. A chromatid is one half of a duplicated chromosome, and a gene is a unit of heredity responsible for specific traits. Therefore, the correct answer is 'Chromosome' as it represents the entire condensed DNA molecule during cell division.

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