Nursing Elites

1. Which organelle in the cell is responsible for protein synthesis?

• A. Ribosome
• B. Nucleus
• C. Mitochondrion
• D. Golgi apparatus

Correct answer: A

Rationale: The correct answer is A: Ribosome. Ribosomes are the organelles responsible for protein synthesis in the cell. They are the cellular machinery where translation, the process of assembling proteins from amino acids based on mRNA sequences, occurs. Ribosomes can be found floating freely in the cytoplasm or attached to the endoplasmic reticulum. The nucleus (choice B) houses DNA but is not directly involved in protein synthesis. Mitochondria (choice C) are responsible for energy production through cellular respiration, not protein synthesis. The Golgi apparatus (choice D) is involved in modifying, sorting, and packaging proteins for secretion, not in the synthesis of proteins.

2. Which of the following is an example of a pivot joint?

• A. Hip
• B. Neck
• C. Shoulder
• D. Elbow

Correct answer: B

Rationale: The correct answer is B: Neck. A pivot joint, as found in the neck, allows for rotational movement around a single axis. This type of joint is essential for movements like shaking your head 'no' or looking left and right. Choices A, C, and D are incorrect because the hip, shoulder, and elbow joints are examples of ball-and-socket joints, which allow for a wide range of motion in multiple directions, not just rotational movement around a single axis like a pivot joint.

3. What potential consequences can chromosomal nondisjunction have on offspring?

• A. Down syndrome, caused by an extra copy of chromosome 21.
• B. Turner syndrome, characterized by the absence of one X chromosome in females.
• C. Klinefelter syndrome, featuring one or more extra X chromosomes in males.
• D. All of the above.

Correct answer: D

Rationale: - Chromosomal nondisjunction is the failure of homologous chromosomes or sister chromatids to separate properly during cell division, leading to an abnormal number of chromosomes in the resulting cells. - Down syndrome is caused by an extra copy of chromosome 21, resulting from nondisjunction during meiosis. Individuals with Down syndrome have three copies of chromosome 21 instead of the usual two. - Turner syndrome is characterized by the absence of one X chromosome in females, leading to a variety of physical and developmental features. - Klinefelter syndrome features one or more extra X chromosomes in males, typically resulting in infertility and other physical characteristics. Therefore, chromosomal nondisjunction can lead to various genetic disorders such as Down syndrome, Turner syndrome, and Klinefelter syndrome, making option D the correct answer.

4. What type of cells compose the epidermis?

• A. Osteoclasts
• B. Connective
• C. Dendritic
• D. Epithelial

Correct answer: D

Rationale: The correct answer is D: Epithelial. The epidermis is composed of epithelial cells, specifically called keratinocytes, which are responsible for producing keratin, a protein that provides the skin with strength and flexibility. Epithelial cells form the protective outer layer of the skin and play a crucial role in skin repair and regeneration. Choice A - Osteoclasts are cells involved in bone remodeling, not found in the epidermis. Choice B - Connective tissue cells are not the primary cells found in the epidermis. They are more commonly found in the dermis, providing structural support and elasticity to the skin. Choice C - Dendritic cells are part of the immune system and are present in the skin to help recognize pathogens and activate the immune response. However, they are not the main cell type that composes the epidermis.

5. A satellite orbits the Earth at a constant speed. Which force is responsible for its circular motion?

• A. Gravitational force from the Earth
• B. Thrust from the satellite's engine
• C. Friction between the satellite and the atmosphere
• D. Normal force from the Earth's surface

Correct answer: A

Rationale: The gravitational force from the Earth is responsible for keeping the satellite in its circular orbit. This force provides the necessary centripetal force required to maintain the circular motion of the satellite. The gravitational force acts as the centripetal force, pulling the satellite towards the center of the Earth, thereby keeping it in its circular path. Choices B, C, and D do not provide the necessary force to keep the satellite in its circular path. Thrust from the satellite's engine would change the speed or direction of the satellite, not maintain its circular path. Friction between the satellite and the atmosphere would act as a resistive force, slowing down the satellite rather than maintaining its orbit. The normal force from the Earth's surface is perpendicular to the surface and does not contribute to the circular motion of the satellite. Therefore, the correct answer is A, as the gravitational force acts as the centripetal force to keep the satellite in its circular path around the Earth.

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