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. What do ligaments connect?

• A. Muscle to muscle
• B. Bone to bone
• C. Bone to muscle
• D. Muscle to tendon

Correct answer: B

Rationale: Ligaments are fibrous connective tissues that connect bone to bone, providing stability and support to joints. They help prevent excessive movement in the joints and maintain proper alignment between bones during movement. Ligaments are not directly involved in connecting muscle to muscle, bone to muscle, or muscle to tendon. Choice A is incorrect because ligaments do not connect muscle to muscle. Choice C is incorrect as ligaments do not connect bone to muscle. Choice D is incorrect as ligaments do not connect muscle to tendon.

3. Which hormone primarily triggers ovulation in the female menstrual cycle?

• A. Estrogen
• B. Progesterone
• C. Luteinizing hormone (LH)
• D. Follicle-stimulating hormone (FSH)

Correct answer: C

Rationale: Luteinizing hormone (LH) is the hormone primarily responsible for triggering ovulation in the female menstrual cycle. LH surge occurs around the middle of the menstrual cycle, causing the mature follicle to release an egg from the ovary. Estrogen and progesterone play crucial roles in regulating the menstrual cycle and preparing the endometrium for potential implantation of a fertilized egg, but they do not trigger ovulation directly. Follicle-stimulating hormone (FSH) is essential for the development of ovarian follicles but is not the primary hormone responsible for ovulation. Therefore, the correct answer is Luteinizing hormone (LH) as it directly initiates the release of the egg during ovulation.

4. How does the stability of an atom's nucleus influence its radioactive decay?

• A. Stable nuclei never undergo radioactive decay.
• B. Unstable nuclei are more likely to decay through various processes.
• C. Decay releases energy, making stable nuclei more prone to it.
• D. The element's position on the periodic table determines its decay rate.

Correct answer: B

Rationale: Unstable nuclei are more likely to decay through various processes. The stability of an atom's nucleus is a crucial factor in determining whether it will undergo radioactive decay. Unstable nuclei have an excess of either protons or neutrons, causing an imbalance in the nucleus. To achieve a more stable configuration, these nuclei will undergo radioactive decay by emitting particles or energy. On the contrary, stable nuclei are less likely to undergo radioactive decay as they possess a balanced number of protons and neutrons. Choice A is incorrect because stable nuclei can still undergo radioactive decay, albeit less frequently. Choice C is incorrect as decay does not make stable nuclei more prone to it; rather, it stabilizes them. Choice D is incorrect because an element's decay rate is primarily determined by the nucleus's stability, not its position on the periodic table.

5. Which organelle is responsible for the final stages of protein modification and packaging for secretion in animal cells?

• A. Rough endoplasmic reticulum (RER)
• B. Smooth endoplasmic reticulum (SER)
• C. Ribosomes
• D. Golgi apparatus

Correct answer: D

Rationale: The Golgi apparatus is responsible for the final stages of protein modification and packaging for secretion in animal cells. After proteins are synthesized in the rough endoplasmic reticulum (RER), they are transported to the Golgi apparatus for further processing, sorting, and packaging before being sent to their final destination within or outside the cell. The smooth endoplasmic reticulum (SER) is mainly involved in lipid metabolism and detoxification processes, not protein modification. Ribosomes are the cellular organelles responsible for protein synthesis, not the final stages of protein modification and packaging for secretion, which is the role of the Golgi apparatus.

Similar Questions