Nursing Elites

1. In a covalent bond, the shared electrons:

• A. Are completely transferred to one atom.
• B. Spend more time closer to the more electronegative atom.
• C. Remain equidistant between the two atoms.
• D. Do not influence the bond strength.

Correct answer: B

Rationale: In a covalent bond, the shared electrons spend more time closer to the more electronegative atom. Electronegativity is the ability of an atom to attract electrons in a chemical bond. The more electronegative atom exerts a stronger pull on the shared electrons, causing them to be closer to that atom. Choice A is incorrect because in a covalent bond, electrons are shared, not completely transferred. Choice C is incorrect as the shared electrons are not equidistant but are closer to one atom due to electronegativity differences. Choice D is incorrect because shared electrons play a significant role in determining the bond strength by the strength of the bond formed through electron sharing.

2. What is the 3D structure of a protein called?

• A. Tertiary structure
• B. Secondary structure
• C. Primary structure
• D. Quaternary structure

Correct answer: A

Rationale: - Primary structure refers to the linear sequence of amino acids in a protein. - Secondary structure refers to local folded structures within a protein, such as alpha helices and beta sheets. - Tertiary structure is the overall 3D shape of a protein, which is determined by interactions between amino acid side chains and the environment. - Quaternary structure refers to the arrangement of multiple protein subunits in a protein complex. Therefore, the 3D structure of a protein is called the tertiary structure because it represents the overall folding of the protein into a specific shape.

3. Which condition involves an overactive immune system attacking healthy tissues, leading to inflammation and damage?

• A. Immunodeficiency
• B. Autoimmune disease
• C. Allergy
• D. Cancer

Correct answer: B

Rationale: Autoimmune diseases occur when the immune system mistakenly targets and attacks healthy tissues in the body, leading to inflammation and damage. This is different from immunodeficiency, where the immune system is weakened and unable to effectively protect the body against infections. Allergies involve an exaggerated immune response to harmless substances, while cancer is characterized by uncontrolled cell growth. Therefore, the correct answer is autoimmune disease (Choice B) as it specifically describes the scenario of an overactive immune system attacking healthy tissues, distinguishing it from the other conditions listed.

4. Which organ is responsible for filtering waste from the blood?

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

Correct answer: A

Rationale: The correct answer is A: Kidneys. The kidneys are responsible for filtering waste products from the blood, maintaining fluid and electrolyte balance. The pancreas aids in digestion and regulates blood sugar levels. The liver processes nutrients, detoxifies chemicals, and produces bile. The heart is responsible for pumping blood throughout the body. Choice B, Pancreas, is incorrect because the pancreas plays a role in digestion and blood sugar regulation, not in filtering waste from the blood. Choice C, Liver, is incorrect as the liver processes nutrients, detoxifies chemicals, and produces bile, but it is not primarily responsible for filtering waste from the blood. Choice D, Heart, is incorrect as the heart's main function is pumping blood throughout the body, not filtering waste from the blood.

5. Which hormone, produced by the pineal gland, plays a role in regulating sleep-wake cycles and is often associated with the body's internal circadian rhythm?

• A. Melatonin
• B. Serotonin
• C. Dopamine
• D. Endorphin

Correct answer: A

Rationale: Melatonin is the hormone produced by the pineal gland that plays a crucial role in regulating sleep-wake cycles and is associated with the body's internal circadian rhythm. Melatonin levels typically rise in the evening, signaling to the body that it is time to sleep, and decrease in the morning, helping to wake up and feel alert. Serotonin, dopamine, and endorphins are neurotransmitters that serve different functions in the body and are not primarily responsible for regulating sleep-wake cycles. Serotonin is involved in regulating mood, appetite, and sleep. Dopamine plays a role in reward-motivated behavior and motor control. Endorphins are involved in pain regulation and are often referred to as the body's natural painkillers.

Similar Questions