Nursing Elites

1. Which of the following is a special property of water?

• A. Water does not easily flow through phospholipid bilayers.
• B. A water molecule's oxygen atom does not allow fish to breathe.
• C. Water is highly cohesive, which explains its high melting point.
• D. Water cannot self-hydrolyze and decompose into hydrogen and oxygen.

Correct answer: C

Rationale: Water is highly cohesive, meaning it is attracted to itself due to its hydrogen bonding properties. This cohesion is the reason why water has a high melting point compared to other liquids of similar molecular weight. It is crucial for the existence of life on Earth as it allows water to remain a liquid within a wide range of temperatures, providing a stable environment for biological processes to occur. Choices A, B, and D are incorrect. Water's cohesive property does not directly relate to its ability to flow through phospholipid bilayers, assist fish in breathing, or self-hydrolyze into hydrogen and oxygen.

2. What is the function of arrector pili muscles?

• A. To control sweat production
• B. To contract and cause goosebumps
• C. To produce sebum
• D. To sense touch

Correct answer: B

Rationale: The correct function of arrector pili muscles is to contract and cause goosebumps. These small muscles are attached to hair follicles in mammals. When they contract, they cause the hair to stand on end, resulting in goosebumps. This physiological response is often triggered by cold temperatures or emotional states like fear, helping mammals conserve heat or appear larger in threatening situations. Choices A, C, and D are incorrect. Arrector pili muscles are not involved in controlling sweat production (Choice A), producing sebum (Choice C), or sensing touch (Choice D).

3. A pediatrician notes that an infant's cartilage is disappearing and being replaced by bone. What process has the doctor observed?

• A. Mineralization
• B. Ossification
• C. Osteoporosis
• D. Calcification

Correct answer: B

Rationale: The doctor has observed the process of ossification. Ossification is the natural process where cartilage in the body is replaced by bone. This process takes place during fetal development, growth, and bone fracture healing. Ossification involves the formation of bone tissue by depositing minerals like calcium and phosphorus within the cartilage matrix, leading to the development of a bone structure. Choice A, mineralization, refers to the process of forming mineral deposits in tissues, but it does not involve the replacement of cartilage by bone. Choice C, osteoporosis, is a condition characterized by bone density loss and increased fragility, not the natural process of cartilage replacement by bone. Choice D, calcification, is the process of deposition of calcium salts in various tissues, but it does not specifically involve the replacement of cartilage by bone as in ossification.

4. Which lifestyle practice can weaken the immune system?

• A. Getting enough sleep
• B. Eating a balanced diet rich in fruits and vegetables
• C. Managing stress levels
• D. Frequent smoking

Correct answer: D

Rationale: Frequent smoking can weaken the immune system by damaging immune cells and impairing their function. Smoking increases the risk of respiratory infections and other illnesses, negatively impacting immune health. Therefore, frequent smoking is a lifestyle practice that can weaken the immune system. Choices A, B, and C are all beneficial practices that support a healthy immune system. Getting enough sleep, eating a balanced diet rich in fruits and vegetables, and managing stress levels are important for maintaining optimal immune function and overall well-being.

5. What do isotopes of the same element have in common?

• A. Identical number of protons and neutrons.
• B. Identical chemical properties.
• C. Identical number of electrons.
• D. Identical mass number.

Correct answer: D

Rationale: Isotopes of the same element have the same number of protons, which defines the element, but different numbers of neutrons. This difference in neutron count results in isotopes of the same element having different mass numbers. Chemical properties are determined by the arrangement of electrons in an atom, so isotopes of the same element may exhibit slightly different chemical behaviors due to different neutron numbers. The number of electrons can vary in isotopes, affecting their charge. However, the mass number, which is the sum of protons and neutrons, is the same for isotopes of the same element. Therefore, the correct answer is that isotopes of the same element share an identical mass number.

Similar Questions