Nursing Elites

1. Which of the following nucleic acids carries amino acids to organelles called ribosomes, where the amino acids are linked one by one to produce a polypeptide?

• A. DNA
• B. mRNA
• C. rRNA
• D. tRNA

Correct answer: D

Rationale: tRNA is the correct answer as it carries amino acids to the ribosomes during protein synthesis. Transfer RNA (tRNA) plays a crucial role in protein synthesis by bringing specific amino acids to the ribosome according to the mRNA sequence. Once at the ribosome, the amino acids are linked together to form a polypeptide chain. This process is essential for the creation of proteins in the cell, highlighting the significance of tRNA in the translation process. Choice A, DNA, is incorrect as DNA does not directly participate in protein synthesis. Choice B, mRNA, is incorrect as mRNA carries the genetic information from DNA to the ribosome but does not directly carry amino acids. Choice C, rRNA, is incorrect as ribosomal RNA is a component of the ribosome structure and is involved in protein synthesis but does not carry amino acids like tRNA.

2. What force causes an object to move in a circular path?

• A. Tension force
• B. Frictional force
• C. Centripetal force
• D. Gravitational force

Correct answer: C

Rationale: The centripetal force is the force responsible for keeping an object moving in a circular path. It is directed towards the center of the circle, providing the necessary inward acceleration to maintain the object's curved trajectory. Without this force, the object would move in a straight line tangent to the circle. Tension force, frictional force, and gravitational force are not the forces that cause an object to move in a circular path. Tension force is typically present in a string or rope and acts along the length of the material. Frictional force opposes the motion of an object relative to a surface, and gravitational force is the force of attraction between two masses.

3. What is the feedback mechanism in the endocrine system that helps maintain hormone balance?

• A. Positive feedback, where a hormone stimulates its own release
• B. Negative feedback, where a hormone suppresses its own release
• C. Cascade effect, where one hormone triggers the release of another
• D. Dual hormone system, where two hormones work together

Correct answer: B

Rationale: In the endocrine system, negative feedback is the mechanism by which hormone levels are regulated. When hormone levels reach a certain threshold, they signal the body to stop producing more of that hormone, thus maintaining a balance. Negative feedback (option B) is the correct answer as it helps in preventing overproduction of hormones by suppressing their own release. Positive feedback (option A) would lead to an excessive production of hormones, disrupting the balance. The cascade effect (option C) involves one hormone triggering the release of another but does not directly regulate hormone levels. The dual hormone system (option D) refers to two hormones working together but does not specifically address the feedback mechanism for maintaining hormone balance.

4. What type of bond forms between elements when they share electrons?

• A. Covalent bond
• B. Ionic bond
• C. Metallic bond
• D. Hydrogen bond

Correct answer: A

Rationale: The correct answer is A: Covalent bond. In a covalent bond, atoms share electrons, leading to the creation of a strong attraction that holds them together. This type of bond is characterized by the sharing of electron pairs between atoms, resulting in the formation of molecules. Choice B, Ionic bond, involves the transfer of electrons from one atom to another, creating charged ions that attract each other. Choice C, Metallic bond, refers to the sharing of electrons among a sea of delocalized electrons in a metal structure. Choice D, Hydrogen bond, is a weak electrostatic attraction between a hydrogen atom and an electronegative atom like oxygen or nitrogen, not involving the sharing of electrons.

5. Which organ system is most responsible for maintaining control of body temperature?

• A. The skeletal system.
• B. The circulatory system.
• C. The immune system.
• D. The muscular system.

Correct answer: B

Rationale: The circulatory system is the correct answer as it plays a crucial role in maintaining control of body temperature through a process called thermoregulation. Blood vessels near the skin surface dilate to dissipate heat when the body is too warm and constrict to reduce heat loss when it's too cold. Additionally, the circulatory system helps distribute heat produced from metabolic processes throughout the body to keep a stable internal temperature. The skeletal system provides structural support, the immune system defends against pathogens, and the muscular system is responsible for movement, but they are not primarily involved in regulating body temperature.

Similar Questions