Nursing Elites

1. What is the difference between a pure substance and a mixture?

• A. Pure substances have a fixed composition, mixtures don't.
• B. Mixtures have a fixed composition, pure substances don't.
• C. Pure substances can be in any state, mixtures are not always solids.
• D. Pure substances are always elements, mixtures are always compounds.

Correct answer: A

Rationale: Pure substances have a definite and constant composition, meaning they are made up of only one type of atom or molecule with fixed proportions. This composition does not vary. On the other hand, mixtures are composed of two or more substances physically combined. The components of a mixture can be present in varying proportions, leading to a variable composition. Choice A is correct as it accurately distinguishes between pure substances and mixtures based on the fixed composition of pure substances and the variable composition of mixtures. Choice B is incorrect because mixtures, not pure substances, have variable compositions. Choice C is incorrect as both pure substances and mixtures can exist in different states. Choice D is incorrect because pure substances can be compounds as well, not exclusively elements, and mixtures can contain elements and compounds.

2. What can the reader conclude from the passage above?

• A. The kingsnake is dangerous to humans.
• B. The coral snake and the kingsnake are both hunted by the same predators.
• C. It's safe to handle snakes in the woods because you can easily tell whether they're poisonous.
• D. The kingsnake changes its markings when hawks or eagles are close by.

Correct answer: B

Rationale: The correct answer is B. The passage explains that the kingsnake mimics the venomous coral snake's markings to deter predators, particularly hawks and eagles, which cannot differentiate between the two species. This implies that both the coral snake and the kingsnake face similar threats from predators in their shared habitat. Choice A is incorrect because the passage clearly states that the kingsnake is nonvenomous, so it is not dangerous to humans. Choice C is incorrect as the passage highlights that not all snakes with flashy markings are venomous, emphasizing the need for caution. Choice D is incorrect as there is no mention of the kingsnake changing its markings in response to the presence of hawks or eagles in the passage.

3. What type of joint connects the bones of the skull?

• A. Hinge joint
• B. Fibrous joint
• C. Ball-and-socket joint
• D. Pivot joint

Correct answer: B

Rationale: The correct answer is B: Fibrous joint. Fibrous joints connect the bones of the skull, providing stability with little to no movement. These joints are made of fibrous connective tissue, which holds the bones tightly together and prevents movement, making them ideal for the structure of the skull. Choice A: Hinge joint is incorrect because hinge joints allow movement in a single plane like the elbow or knee, which is not characteristic of the joints in the skull. Choice C: Ball-and-socket joint is incorrect as this type of joint allows for a wide range of movement in multiple planes, such as the hip and shoulder joints, which is not the case for skull bones. Choice D: Pivot joint is incorrect as pivot joints allow rotation around a central axis, as seen in the joint between the first and second cervical vertebrae (atlas and axis), but not in the skull bones.

4. Blood is carried away from the heart in large vessels known as which of the following?

• A. Arteries
• B. Arterioles
• C. Veins
• D. Venules

Correct answer: A

Rationale: The correct answer is A: Arteries. Arteries are the large blood vessels that carry blood away from the heart to various parts of the body. They have thick, muscular walls to withstand the high pressure generated by the heart's pumping action. Choice B, Arterioles, are smaller branches of arteries that further divide into capillaries. Choice C, Veins, carry blood back to the heart and have thinner walls compared to arteries. Choice D, Venules, are smaller veins that collect blood from capillaries and merge into larger veins.

5. As part of a study, a set of patients will be divided into three groups: 1/2 of the patients will be in Group Alpha, 1/3 of the patients will be in Group Beta, and 1/6 of the patients will be in Group Gamma. Order the groups from smallest to largest, according to the number of patients in each group.

• A. Group Alpha, Group Beta, Group Gamma
• B. Group Alpha, Group Gamma, Group Beta
• C. Group Gamma, Group Alpha, Group Beta
• D. Group Gamma, Group Beta, Group Alpha

Correct answer: C

Rationale: The correct order from smallest to largest number of patients in each group is Group Gamma (1/6), Group Alpha (1/2), and Group Beta (1/3). Group Gamma has the smallest fraction of patients, followed by Group Alpha and then Group Beta. Therefore, choice C, 'Group Gamma, Group Alpha, Group Beta,' is the correct answer. Choices A, B, and D are incorrect because they do not follow the correct order based on the fractions of patients assigned to each group.

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