Nursing Elites

1. What is the CRISPR-Cas9 system used for in gene editing?

• A. To amplify specific DNA sequences.
• B. To cut DNA at specific locations.
• C. To deliver genes into cells.
• D. To sequence entire genomes.

Correct answer: B

Rationale: Rationale: The CRISPR-Cas9 system is a powerful tool used in gene editing to precisely target and cut DNA at specific locations within the genome. This system consists of a guide RNA that directs the Cas9 enzyme to the desired DNA sequence, where it creates a double-strand break. This break can then be repaired by the cell's natural DNA repair mechanisms, allowing for the introduction of specific genetic modifications. Options A, C, and D do not accurately describe the primary function of the CRISPR-Cas9 system in gene editing.

2. What phenomenon occurs when two identical waves are perfectly aligned and reinforce each other?

• A. Refraction
• B. Reflection
• C. Diffraction
• D. Constructive interference

Correct answer: d

Rationale: Constructive interference happens when identical waves meet in phase, resulting in a wave with increased amplitude.

3. The longest bone in the human body is the:

• A. Tibia
• B. Fibula
• C. Femur
• D. Humerus

Correct answer: C

Rationale: The correct answer is C: "Femur." The femur is the longest bone in the human body, located in the thigh region and connecting the hip to the knee. It plays a crucial role in supporting the body's weight and facilitating movement. The tibia and fibula are bones in the lower leg, while the humerus is a bone in the upper arm. Therefore, the femur is the correct answer for the longest bone in the human body.

4. The Merkel cells, located in the epidermis, are specialized for:

• A. Melanin production
• B. Temperature sensation
• C. Touch perception
• D. Immune defense

Correct answer: C

Rationale: The correct answer is C: 'Touch perception.' Merkel cells, also known as Merkel discs, are found in the skin's epidermal layer and are responsible for sensing touch. These cells are located near nerve endings and help detect light touch and pressure on the skin. They play a crucial role in the perception of tactile sensations and are not involved in melanin production, temperature sensation, or immune defense. Therefore, the specialized function of Merkel cells is primarily related to touch perception, making option C the correct choice.

5. Neurons, the functional units of the nervous system, belong to which tissue type?

• A. Epithelial tissue
• B. Connective tissue
• C. Muscle tissue
• D. Nervous tissue

Correct answer: D

Rationale: The correct answer is D: Nervous tissue. Neurons are specialized cells that transmit nerve impulses and are the primary components of the nervous system. Nervous tissue is made up of neurons and supporting cells called neuroglia. Neurons are responsible for processing and transmitting information throughout the body, making them a crucial part of the nervous system. Epithelial tissue (A) is primarily involved in covering and lining surfaces, connective tissue (B) supports and connects other tissues, and muscle tissue (C) is responsible for movement. Therefore, neurons belong to nervous tissue, which is specialized for communication and coordination within the body.

6. What is the difference between a real image and a virtual image formed by a lens?

• A. Real images can be projected onto a screen, while virtual images cannot.
• B. Real images are always upright, while virtual images can be inverted.
• C. Real images are formed by converging lenses, while virtual images are formed by diverging lenses.
• D. All of the above are true.

Correct answer: A

Rationale: Real images are formed by the actual convergence of light rays and can be projected onto a screen, while virtual images are formed by the apparent divergence of light rays and cannot be projected.

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