Nursing Elites

1. Which type of cell has a nucleus but lacks membrane-bound organelles?

• A. Plant cell
• B. Prokaryotic cell
• C. Animal cell
• D. Fungal cell

Correct answer: B

Rationale: The correct answer is B: Prokaryotic cell. Prokaryotic cells are characterized by having a nucleus that is not enclosed within a membrane (nuclear envelope) and lacking membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus. Plant, animal, and fungal cells are eukaryotic cells, which have a true nucleus enclosed within a nuclear envelope and contain membrane-bound organelles. Therefore, options A, C, and D are incorrect as they all represent eukaryotic cells that possess membrane-bound organelles.

2. Which part of the heart is responsible for generating the QRS complex on an ECG?

• A. Sinoatrial node (SA node)
• B. Atrioventricular node (AV node)
• C. Bundle of His
• D. Ventricular muscle cells

Correct answer: D

Rationale: The QRS complex on an ECG represents ventricular depolarization. This electrical activity is generated by the ventricular muscle cells. While the SA node generates the P wave, the AV node delays the impulse, and the Bundle of His and Purkinje fibers assist in rapidly conducting the impulse through the ventricles, it is the ventricular muscle cells that specifically create the QRS complex. Therefore, choice D, Ventricular muscle cells, is the correct answer. Choices A, B, and C are incorrect as they are primarily involved in initiating and coordinating the electrical impulses in the heart but do not directly generate the QRS complex on an ECG.

3. Which of the following nucleic acids carries the genetic information copied from DNA to the ribosomes?

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

Correct answer: B

Rationale: The correct answer is B: mRNA. Messenger RNA (mRNA) is responsible for carrying the genetic information copied from DNA to the ribosomes for protein synthesis. mRNA serves as a temporary copy of the genetic instructions stored in DNA and acts as a messenger between the nucleus and ribosomes in the cytoplasm where protein synthesis occurs. While rRNA (ribosomal RNA) and tRNA (transfer RNA) play essential roles in the process of translation at the ribosomes, mRNA is the nucleic acid directly involved in carrying the genetic code for protein synthesis. Therefore, choices A, C, and D are incorrect as DNA is the original genetic material, rRNA is a component of the ribosomes, and tRNA carries amino acids during protein synthesis, respectively.

4. As a car accelerates from rest, what happens to its kinetic energy and the work done on it?

• A. Both kinetic energy and work done increase.
• B. Kinetic energy increases, but work done remains constant.
• C. Work done increases, but kinetic energy remains constant.
• D. Both kinetic energy and work done remain constant.

Correct answer: A

Rationale: When a car accelerates from rest, its speed and kinetic energy increase. The work done on the car is what increases its kinetic energy, so both kinetic energy and work done increase simultaneously. Option A is correct because acceleration results in an increase in both kinetic energy and the work done on the car. Option B is incorrect because work done is required to increase kinetic energy during acceleration. Option C is incorrect as work done is directly related to the change in kinetic energy. Option D is incorrect as both kinetic energy and work done increase when the car accelerates.

5. Differentiate between genotype and phenotype in the context of gene expression.

• A. Genotype refers to the physical manifestation of a trait, while phenotype represents its underlying genetic makeup.
• B. Genotype encompasses the spectrum of possible traits encoded by an organism's genes, while phenotype signifies the specific trait observed.
• C. Genotype denotes the presence of dominant alleles, while phenotype reflects the influence of recessive alleles.
• D. There is no distinction; both terms are interchangeable.

Correct answer: B

Rationale: - Genotype refers to the genetic makeup of an organism, including all the genes and alleles it possesses. - Phenotype, on the other hand, refers to the observable physical characteristics or traits of an organism, which result from the interaction between its genotype and the environment. - While genotype represents the genetic potential or range of traits that an organism can express, phenotype reflects the actual expression of specific traits. - Therefore, option B correctly captures the distinction between genotype and phenotype in the context of gene expression.

Similar Questions