HESI A2
HESI A2 Biology 2024
1. What process do cells in the tip of a plant’s root undergo to increase in number?
- A. Meiosis
- B. Cytokinesis
- C. Fractioning
- D. Mitosis
Correct answer: D
Rationale: Cells in the tip of a plant's root undergo the process of mitosis to increase in number. Mitosis is a type of cell division that results in two daughter cells with the same number of chromosomes as the parent cell. This process allows for growth and maintenance of tissues in plants by producing new cells through division. Choice A, Meiosis, is incorrect as meiosis is a type of cell division that reduces the number of chromosomes in cells to produce gametes. Choice B, Cytokinesis, is incorrect as it is the division of the cytoplasm following cell division. Choice C, Fractioning, is not a biological process related to cell division.
2. Genes control heredity in man and other organisms. This gene is ___
- A. A segment of DNA
- B. A bead-like structure on the chromosomes
- C. A protein molecule
- D. A segment of RNA
Correct answer: A
Rationale: Genes are sections of DNA that contain instructions for building and operating living organisms. These sections of DNA contain the genetic information that is passed on from one generation to the next. Genes are composed of specific sequences of nucleotides within the DNA molecule. Therefore, genes are best described as segments of DNA. Choice A is correct. Choice B is incorrect because genes are not bead-like structures on chromosomes but specific sequences of DNA. Choice C is incorrect because genes are not protein molecules but rather sequences of nucleotides. Choice D is incorrect because genes are not segments of RNA but DNA.
3. Tonicity refers to the movement of:
- A. Water
- B. Solute
- C. Cells
- D. None of the above
Correct answer: A
Rationale: Tonicity refers to the movement of water across a membrane in response to differences in solute concentration. In a hypertonic solution, where there is a higher concentration of solutes outside the cell, water will move out of the cell to try to reach equilibrium. In a hypotonic solution, where there is a lower concentration of solutes outside the cell, water will move into the cell to balance the concentrations. Cells and solutes themselves do not actively move in response to tonicity; it is the movement of water that helps achieve equilibrium. Therefore, the correct answer is water (Choice A). Choices B, C, and D are incorrect as tonicity specifically refers to water movement and not the movement of solutes, cells, or none of the above.
4. Which type of passive transport uses proteins that change shape to move a target molecule through the membrane?
- A. Diffusion
- B. Carrier proteins
- C. Channel proteins
- D. None of the above
Correct answer: B
Rationale: The correct answer is B: Carrier proteins. Carrier proteins are involved in facilitated diffusion, a type of passive transport where specific target molecules are moved across the membrane with the help of proteins that change shape. These carrier proteins bind to the target molecule on one side of the membrane, undergo a conformational change, and then release the molecule on the other side. This process is crucial for the selective transport of certain molecules that cannot pass through the membrane by simple diffusion. Choices A and C are incorrect because diffusion and channel proteins do not involve proteins that change shape to transport target molecules selectively. Choice D is incorrect as carrier proteins fit the description provided in the question.
5. Why doesn't an antibiotic work for treating the flu?
- A. The antibiotic is for a different type of infection
- B. The antibiotic is not effective against viruses
- C. The antibiotic is not prescribed in a high enough dosage
- D. None of the above
Correct answer: B
Rationale: The correct answer is B. Antibiotics are used to treat bacterial infections, not viral infections like the flu. The flu is caused by a virus, and antibiotics are ineffective against viruses. Choice A is incorrect because it does not address the fact that antibiotics do not work on viruses. Choice C is incorrect as the issue is not related to the dosage amount, but rather the nature of the infection. Choice D is incorrect as there is a specific reason why antibiotics do not work for the flu.
Similar Questions
Access More Features
HESI A2 Basic
$89/ 30 days
- 3,000 Questions with answers
- 30 days access
HESI A2 Premium
$129.99/ 90 days
- Actual HESI A2 Questions
- 3,000 questions with answers
- 90 days access