Nursing Elites

1. What is the function of introns in eukaryotic genes?

• A. They code for protein sequences.
• B. They are involved in gene regulation.
• C. They are removed during mRNA processing.
• D. They are non-functional remnants of ancient DNA.

Correct answer: C

Rationale: A) Introns do not code for protein sequences. Exons are the segments of DNA that code for proteins. B) While introns can indirectly influence gene regulation, their primary function is not directly involved in gene regulation. C) Introns are non-coding regions of DNA that are transcribed into pre-mRNA but are removed during mRNA processing through a process called splicing. This allows only the exons to be included in the mature mRNA that will be translated into proteins. D) While introns were once thought to be non-functional remnants of ancient DNA, research has shown that they can have regulatory functions and play a role in gene expression.

2. Which layer of the skin is responsible for new skin cell production?

• A. Stratum corneum
• B. Stratum basale
• C. Stratum granulosum
• D. Stratum spinosum

Correct answer: B

Rationale: The correct answer is B, Stratum basale. The stratum basale, also known as the basal layer or stratum germinativum, is the deepest layer of the epidermis and is responsible for new skin cell production through cell division. It contains basal cells that continuously divide to produce new keratinocytes, which move up through the layers of the epidermis. Choice A, Stratum corneum, is the outermost layer of the epidermis consisting of dead cells filled with keratin. It serves a protective function but is not involved in new skin cell production. Choice C, Stratum granulosum, is a layer of the epidermis where keratinocytes undergo changes in their structure and composition. It is involved in the process of keratinization but not in new skin cell production. Choice D, Stratum spinosum, is a layer of the epidermis where cells become interconnected by desmosomes. While it plays a role in providing strength and support to the epidermis, it is not primarily responsible for new skin cell production.

3. What is the difference between a prokaryotic cell and a eukaryotic cell?

• A. Prokaryotic cells have a nucleus, while eukaryotic cells do not
• B. Eukaryotic cells have a nucleus, while prokaryotic cells do not.
• C. Prokaryotic cells have membrane-bound organelles, while eukaryotic cells do not.
• D. Eukaryotic cells have membrane-bound organelles, while prokaryotic cells do not.

Correct answer: B

Rationale: - Prokaryotic cells are simpler and do not have a true nucleus. Their genetic material is located in the nucleoid region, which is not enclosed by a membrane. - Eukaryotic cells are more complex and have a true nucleus that houses the genetic material, enclosed within a nuclear membrane. - Both prokaryotic and eukaryotic cells have organelles, but eukaryotic cells have membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus, while prokaryotic cells lack these membrane-bound organelles.

4. Which of the following organs is part of the central nervous system?

• A. Heart
• B. Brain
• C. Liver
• D. Lungs

Correct answer: B

Rationale: The correct answer is B: Brain. The brain is a vital organ that is part of the central nervous system, along with the spinal cord. It plays a crucial role in processing information, controlling body functions, and coordinating responses to stimuli. The heart, liver, and lungs are not part of the central nervous system; they belong to the cardiovascular and respiratory systems, respectively. The heart is part of the cardiovascular system, responsible for pumping blood throughout the body. The liver is part of the digestive system, involved in processes like detoxification and metabolism. The lungs are part of the respiratory system, facilitating the exchange of oxygen and carbon dioxide during breathing.

5. Which muscle has involuntary cells that are branched and striated and connected by intercalated discs with gap junctions?

• A. Smooth muscle
• B. Cardiac muscle
• C. Skeletal muscle
• D. Epithelial muscle

Correct answer: B

Rationale: The correct answer is B: Cardiac muscle. Cardiac muscle cells fit the description provided in the question; they are involuntary, striated, and branched, with intercalated discs containing gap junctions that allow for synchronized contractions of the heart. Smooth muscle (choice A) lacks striations and is found in the walls of internal organs. Skeletal muscle (choice C) is voluntary and attaches to bones for movement. 'Epithelial muscle' (choice D) is not a valid muscle type, making it an incorrect choice.

Similar Questions