Nursing Elites

1. Fill in the blanks in the following sentence: Enzymes are ________ molecules that serve as _______ for certain biological reactions.

• A. complex; suppressors
• B. acidic; triggers
• C. small; targets
• D. large; catalysts

Correct answer: D

Rationale: Enzymes are large molecules that act as catalysts, accelerating chemical reactions by lowering the activation energy required for the reactions to occur. In the context of biological reactions, enzymes function as catalysts, not suppressors, triggers, or targets. The use of 'large' and 'catalysts' accurately describes the nature and role of enzymes in facilitating biological processes.

2. What is the common name for the compound CH₃COOH?

• A. Acetic acid
• B. Formic acid
• C. Butyric acid
• D. Propionic acid

Correct answer: A

Rationale: The compound CH₃COOH is commonly known as acetic acid. Acetic acid is a clear, colorless liquid with a sour taste and a pungent smell. It is a weak acid found in vinegar and is used in the production of various chemicals. Formic acid, butyric acid, and propionic acid are different organic acids with distinct chemical structures and properties, but they are not the common name for the compound CH₃COOH.

3. Which hormone, produced by the thyroid gland, plays a crucial role in regulating the body's metabolism, growth, and development?

• A. Calcitonin
• B. Parathyroid hormone (PTH)
• C. Thyroxine
• D. Insulin

Correct answer: C

Rationale: Thyroxine, also known as T4, is a hormone produced by the thyroid gland that plays a crucial role in regulating the body's metabolism, growth, and development. It helps control the rate at which the body uses energy, affects protein synthesis, and influences the body's sensitivity to other hormones. Calcitonin (A) is another hormone produced by the thyroid gland, but its primary function is to regulate calcium levels in the blood. Parathyroid hormone (PTH) (B) is produced by the parathyroid glands and is involved in regulating calcium and phosphorus levels in the body. Insulin (D) is a hormone produced by the pancreas that helps regulate blood sugar levels.

4. What is the process of copying DNA called?

• A. Transcription
• B. Translation
• C. Replication
• D. Mutation

Correct answer: C

Rationale: The correct answer is C, Replication. Replication is the process of making an identical copy of DNA. During replication, the DNA double helix unwinds, and each strand serves as a template for the synthesis of a new complementary strand, resulting in two identical DNA molecules. Transcription (choice A) involves the synthesis of mRNA from a DNA template, not the direct copying of DNA. Translation (choice B) is the process of converting mRNA into a sequence of amino acids to form a protein, not copying DNA. Mutation (choice D) refers to changes in the DNA sequence, which can occur during replication but is not the process of copying DNA itself.

5. Scientists compare the DNA of different organisms to understand evolutionary relationships. What is this type of evidence called?

• A. Morphological evidence (comparing body structures)
• B. Biochemical evidence (comparing molecules like proteins)
• C. Geographic distribution evidence (where organisms live)
• D. Genetic evidence (comparing DNA sequences)

Correct answer: D

Rationale: A) Morphological evidence involves comparing body structures of organisms, which can provide information about evolutionary relationships based on physical similarities and differences. However, DNA comparison is a more direct and accurate method for understanding evolutionary relationships. B) Biochemical evidence involves comparing molecules like proteins, which can also provide insights into evolutionary relationships. However, DNA comparison is considered more reliable due to the direct relationship between DNA sequences and genetic information. C) Geographic distribution evidence refers to where organisms live and how their distribution may provide clues about evolutionary history. While this can be informative, it is not as direct or specific as comparing DNA sequences. D) Genetic evidence involves comparing DNA sequences of different organisms to understand their evolutionary relationships. DNA comparison is a powerful tool in evolutionary biology because it provides direct information about genetic similarities and differences, offering precise insights into evolutionary relationships.

Similar Questions