Nursing Elites

1. In meiosis I, how are sister chromatids distinguished from homologous chromosomes?

• A. Sister chromatids share the same centromere, while homologues have different centromeres.
• B. Sister chromatids have identical DNA sequences, while homologues have slightly different sequences due to crossing over.
• C. Sister chromatids repel each other, while homologues attract each other during synapsis.
• D. Sister chromatids separate during anaphase I, while homologues separate during anaphase II.

Correct answer: B

Rationale: While sister chromatids are identical copies of the same chromosome, homologous chromosomes are paired copies, each inherited from one parent. Crossing over during meiosis I can lead to slight differences in their DNA sequences.

2. Unlike the circulatory system, the lymphatic system does not have a pump. How does lymph move through the lymphatic vessels?

• A. By the pumping action of the heart
• B. Due to muscle contractions and breathing movements
• C. Through one-way valves within the vessels
• D. All of the above

Correct answer: D

Rationale: The correct answer is D, 'All of the above.' Unlike the circulatory system which relies on the heart's pumping action, the lymphatic system lacks a central pump. Lymph moves through lymphatic vessels primarily due to muscle contractions and breathing movements that squeeze the vessels, helping propel the lymph forward. Additionally, one-way valves within the lymphatic vessels prevent the backward flow of lymph, ensuring it moves in the right direction. Therefore, all three mechanisms - heart pumping, muscle contractions, and one-way valves - work together to facilitate the movement of lymph through the lymphatic system.

3. Two scientists analyze the same data set on climate change, but they reach different conclusions. What is the MOST likely reason for this difference?

• A. One scientist has more experience than the other.
• B. They used different statistical methods.
• C. They have different personal biases.
• D. One scientist has access to additional data.

Correct answer: B

Rationale: Different analysis methods can lead to different interpretations, even with the same data. Biases and experience might play a role but are less likely the primary cause.

4. Which type of joint allows for the most movement?

• A. Ball-and-socket joint (shoulder)
• B. Hinge joint (elbow)
• C. Fibrocartilaginous joint (wrists)
• D. Suture joint (skull)

Correct answer: A

Rationale: The correct answer is A: Ball-and-socket joint (shoulder). Ball-and-socket joints allow for the most movement in all directions, such as flexion, extension, abduction, adduction, and rotation. The shoulder joint is a prime example, as it enables a wide range of motion, allowing the arm to move in multiple planes. Hinge joints, like the elbow, primarily allow movement in one direction (flexion and extension). Fibrocartilaginous joints, such as those in the wrists, have limited movement due to the presence of cartilage between the bones. Suture joints, found in the skull, are immovable joints that provide structural support rather than movement. Therefore, ball-and-socket joints like the shoulder joint offer the greatest range of motion among the options provided.

5. Which part of the neuron receives incoming signals from other neurons and conducts them toward the cell body?

• A. Axon
• B. Dendrite
• C. Synapse
• D. Myelin sheath

Correct answer: b

Rationale: The correct answer is B: Dendrite. Dendrites are the part of the neuron that receive incoming signals from other neurons and conduct them toward the cell body. They play a crucial role in communication between neurons by receiving neurotransmitters released from neighboring neurons. Axons transmit signals away from the cell body, synapses are the junctions where neurons communicate with each other, and myelin sheath is a fatty insulation that surrounds and protects axons. Therefore, in this scenario, dendrites are specifically responsible for receiving and conducting incoming signals towards the cell body.

6. Which of the following describes a scalar quantity?

• A. Velocity
• B. Acceleration
• C. Force
• D. Speed

Correct answer: d

Rationale: Speed is a scalar quantity as it only indicates how fast an object is moving without any directional information.

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