Nursing Elites

1. Which of the following is NOT a mechanism that can directly cause evolution by natural selection?

• A. Mutations in genes
• B. Differential survival and reproduction based on traits
• C. Inheritance of acquired characteristics (like strong muscles from working out)
• D. Competition for resources in an environment

Correct answer: C

Rationale: A) Mutations in genes can introduce new genetic variations into a population, which can be acted upon by natural selection. B) Differential survival and reproduction based on traits is a key component of natural selection, as individuals with advantageous traits are more likely to survive and pass on their genes to the next generation. C) Inheritance of acquired characteristics, also known as Lamarckism, is not a mechanism of evolution by natural selection. Traits acquired during an individual's lifetime (such as strong muscles from working out) are not passed on to offspring. D) Competition for resources in an environment can drive natural selection by favoring individuals with traits that help them better compete for limited resources. Therefore, the correct answer is C) Inheritance of acquired characteristics (like strong muscles from working out), as it is not a mechanism that can directly cause evolution by natural selection.

2. What type of chemical bond connects the oxygen and hydrogen atoms in a molecule of water?

• A. Static bond
• B. Aquatic bond
• C. Ionic bond
• D. Covalent bond

Correct answer: D

Rationale: The correct answer is D, Covalent bond. Covalent bonds are formed between oxygen and hydrogen atoms in a water molecule. In a water molecule, each hydrogen atom forms a covalent bond with the oxygen atom, sharing electrons to achieve a stable configuration. Static bond (choice A) and Aquatic bond (choice B) are not valid types of chemical bonds. Ionic bond (choice C) involves the transfer of electrons between atoms of different electronegativities, which is not the case between oxygen and hydrogen in a water molecule.

3. A car is accelerating down a hill. Which of the following forces is NOT acting on the car?

• A. Gravitational force
• B. Normal force from the road
• C. Air resistance
• D. The car's engine force

Correct answer: B

Rationale: When a car is accelerating down a hill, the normal force from the road is not acting on the car. The normal force is the force exerted by a surface to support the weight of an object resting on it. As the car moves downhill, the normal force decreases since the road is no longer pushing back against the car's weight due to the downhill motion. Gravitational force pulls the car downhill, air resistance opposes the car's motion, and the car's engine force propels it forward. Therefore, the correct answer is B, as the normal force from the road is not acting on the car while it accelerates downhill.

4. Which of the following types of immunity is provided by the secretion of antibodies by B-cells?

• A. Cell-mediated
• B. Humoral
• C. Innate immunity
• D. Phagocytic

Correct answer: B

Rationale: The correct answer is B: Humoral. Humoral immunity involves B-cells secreting antibodies to fight pathogens. In this type of immunity, antibodies circulate in the blood and other body fluids to neutralize pathogens and prevent infections. Cell-mediated immunity, on the other hand, involves the activation of T-cells to directly attack infected or abnormal cells, not the secretion of antibodies. Innate immunity refers to the nonspecific defense mechanisms the body has in place from birth, such as physical barriers and inflammatory responses. Phagocytic immunity is not a recognized type of immunity; phagocytosis is a mechanism used by cells like macrophages to engulf and digest pathogens, but it is not a specific form of immunity like humoral or cell-mediated immunity.

5. Which organ in the human body is responsible for filtering blood and producing urine?

• A. Liver
• B. Kidneys
• C. Pancreas
• D. Heart

Correct answer: B

Rationale: The correct answer is B: Kidneys. The kidneys are vital organs in the human body responsible for filtering blood to remove waste products and excess substances, producing urine as a result. The liver plays a role in detoxification and metabolism. The pancreas is involved in digestion and blood sugar regulation. The heart pumps blood throughout the body but does not filter blood or produce urine.

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