Free PSB-RN Natural Sciences (Biology, Chemistry & Physics) Questions and Answers — Questions and Answers
Question 1: Which organelle is responsible for ATP production in human cells?
- Nucleus
- Mitochondria (Correct answer)
- Golgi apparatus
- Endoplasmic reticulum
Correct answer: Mitochondria
Mitochondria are often referred to as the 'powerhouses' of the cell because they are the primary sites of cellular respiration. During this process, glucose and oxygen are converted into adenosine triphosphate (ATP), which is the main energy currency used by the cell for various functions.
Question 2: What is the normal pH range of human blood?
- 6.8-7.0
- 7.35-7.45 (Correct answer)
- 7.5-8.0
- 6.0-7.2
Correct answer: 7.35-7.45
The normal pH range of human blood is tightly regulated between 7.35 and 7.45, making it slightly alkaline. Maintaining this narrow range is crucial for proper physiological function, as deviations can lead to serious health complications like acidosis or alkalosis.
Question 3: Which law explains why intravenous fluids must be administered at specific heights?
- Ohm's Law
- Bernoulli's Principle
- Pascal's Law
- Gravity and Hydrostatic Pressure (Correct answer)
Correct answer: Gravity and Hydrostatic Pressure
Intravenous fluids are administered using gravity to create hydrostatic pressure, which drives the fluid into the patient's vein. The height of the IV bag above the patient determines the amount of gravitational force and thus the pressure, influencing the flow rate of the fluid.
Question 4: What type of chemical bond holds water molecules together?
- Ionic bonds
- Hydrogen bonds (Correct answer)
- Covalent bonds
- Metallic bonds
Correct answer: Hydrogen bonds
Water molecules are polar, meaning they have a slight positive charge on the hydrogen atoms and a slight negative charge on the oxygen atom. This polarity allows hydrogen bonds to form between the hydrogen of one water molecule and the oxygen of an adjacent water molecule, giving water its unique properties.
Question 5: Which blood vessels carry oxygenated blood from the lungs to the heart?
- Pulmonary arteries
- Pulmonary veins (Correct answer)
- Coronary arteries
- Aorta
Correct answer: Pulmonary veins
In the circulatory system, pulmonary veins are responsible for carrying oxygenated blood from the lungs back to the left atrium of the heart. Pulmonary arteries, conversely, carry deoxygenated blood from the heart to the lungs.
Question 6: What is the primary function of red blood cells?
- Fight infection
- Transport oxygen (Correct answer)
- Produce antibodies
- Form blood clots
Correct answer: Transport oxygen
The primary function of red blood cells (erythrocytes) is to transport oxygen from the lungs to the body's tissues. This is achieved through hemoglobin, a protein within red blood cells that binds reversibly to oxygen.
Question 7: Which gas law explains why a sealed IV bag expands at higher altitudes?
- Boyle's Law (Correct answer)
- Charles's Law
- Avogadro's Law
- Henry's Law
Correct answer: Boyle's Law
Boyle's Law states that for a fixed amount of gas at constant temperature, pressure and volume are inversely proportional. At higher altitudes, atmospheric pressure is lower, allowing the gas inside a sealed IV bag to expand and increase its volume, causing the bag to appear inflated.
Question 8: What is the chemical symbol for potassium?
- P
- Pt
- K (Correct answer)
- Ko
Correct answer: K
The chemical symbol for potassium is 'K'. This symbol is derived from its Latin name, 'kalium'. It is important for nurses to know common chemical symbols, especially for electrolytes, as they are frequently encountered in patient care and lab results.
Question 9: Which process describes the movement of water across a semipermeable membrane?
- Diffusion
- Osmosis (Correct answer)
- Active transport
- Filtration
Correct answer: Osmosis
Osmosis is specifically defined as the net movement of water molecules across a selectively permeable membrane from an area of higher water concentration (lower solute concentration) to an area of lower water concentration (higher solute concentration). This process is crucial for maintaining fluid balance in the body.
Free PSB-RN Natural Sciences (Biology, Chemistry & Physics) Questions and Answers
Which organelle is responsible for ATP production in human cells?