Nursing Elites

1. What is the 3D structure of a protein called?

• A. Tertiary structure
• B. Secondary structure
• C. Primary structure
• D. Quaternary structure

Correct answer: A

Rationale: - Primary structure refers to the linear sequence of amino acids in a protein. - Secondary structure refers to local folded structures within a protein, such as alpha helices and beta sheets. - Tertiary structure is the overall 3D shape of a protein, which is determined by interactions between amino acid side chains and the environment. - Quaternary structure refers to the arrangement of multiple protein subunits in a protein complex. Therefore, the 3D structure of a protein is called the tertiary structure because it represents the overall folding of the protein into a specific shape.

2. What is the role of transfer RNA (tRNA) in protein synthesis?

• A. Transcribes DNA into mRNA
• B. Decodes the genetic code on mRNA
• C. Carries specific amino acids to the ribosomes
• D. Modifies the structure of proteins

Correct answer: C

Rationale: A) Transcribes DNA into mRNA: This is the function of RNA polymerase, not transfer RNA (tRNA). tRNA is involved in protein synthesis, not transcription. B) Decodes the genetic code on mRNA: This is the function of tRNA during translation. tRNA molecules carry specific amino acids and recognize the codons on mRNA, ensuring the correct amino acid is added to the growing polypeptide chain. C) Carries specific amino acids to the ribosomes: This is the primary role of tRNA in protein synthesis. Each tRNA molecule is specific for a particular amino acid and carries it to the ribosome, where it is added to the growing protein chain. D) Modifies the structure of proteins: This is not a function of tRNA. Protein modification can occur after translation is complete and involves other cellular processes and molecules.

3. What type of bond connects amino acids to form proteins?

• A. Covalent
• B. Peptide
• C. Ionic
• D. Hydrogen

Correct answer: B

Rationale: The correct answer is 'Peptide'. Peptide bonds are the specific type of bond that connects amino acids together to form proteins. These bonds form through a condensation reaction between the amino group of one amino acid and the carboxyl group of another amino acid, creating a covalent bond. While covalent bonds are involved in the formation of peptide bonds, the direct bond connecting amino acids in proteins is the peptide bond. Ionic bonds involve the attraction between charged particles, and hydrogen bonds are weaker bonds compared to covalent and peptide bonds, playing a different role in protein structure.

4. According to the theory of evolution by natural selection, which of the following statements is true?

• A. Organisms evolve towards perfection
• B. Traits are acquired through use and disuse
• C. Individuals with favorable traits survive and reproduce more
• D. All of the above

Correct answer: C

Rationale: Rationale: A) Organisms evolve towards perfection - This statement is incorrect. Evolution by natural selection does not suggest that organisms evolve towards perfection. Instead, it emphasizes the adaptation of organisms to their environment over time. B) Traits are acquired through use and disuse - This statement reflects Lamarck's theory of evolution, not Darwin's theory of evolution by natural selection. Lamarck proposed that organisms could acquire traits during their lifetime and pass them on to their offspring, which has been largely discredited. C) Individuals with favorable traits survive and reproduce more - This statement accurately reflects the central concept of Darwin's theory of evolution by natural selection. Individuals with traits that are advantageous in their environment are more likely to survive and reproduce, passing on those traits to future generations. D) All of the above - This option is incorrect because not all of the statements are true. Only option C accurately represents the theory of evolution by natural selection.

5. Which of the following structures in the male reproductive system produces the fluid that carries sperm?

• A. Testes
• B. Scrotum
• C. Prostate gland
• D. Seminal vesicles

Correct answer: D

Rationale: The seminal vesicles in the male reproductive system are responsible for producing the fluid that carries sperm. These glands contribute a significant portion of the semen's volume, providing nutrients and protection for the sperm, which helps in their motility and survival. The testes are responsible for producing sperm cells, not the fluid that carries them. The scrotum is the external sac that holds the testes and helps regulate their temperature but does not produce the fluid. The prostate gland produces a milky fluid that helps nourish and protect sperm but is not the main structure responsible for producing the fluid that carries sperm.

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