which if any of the following statements are true

HESI A2

HESI A2 Biology Practice Test

1. Which, if any, of the following statements are true?

A. Water boils at approximately 100°C (212°F) at standard atmospheric pressure
B. The boiling point is the temperature at which the vapor pressure is higher than the atmospheric pressure around the water
C. Water boils at a lower temperature in areas of lower pressure
D. A and C are true

Correct answer: D

Rationale: Both statements A and C are true. Water indeed boils at approximately 100°C (212°F) at standard atmospheric pressure. However, water boils at a lower temperature in areas of lower pressure due to the decreased atmospheric pressure, which affects the vapor pressure and boiling point of water. Statement B is incorrect because the boiling point is the temperature at which the vapor pressure equals the external pressure (atmospheric pressure in this case), not when it is higher.

2. Why do we perceive chlorophyll as green?

A. It absorbs yellow and blue light.
B. It primarily absorbs green light.
C. It fails to absorb green light.
D. It primarily absorbs red light.

Correct answer: A

Rationale: Chlorophyll appears green to us because it primarily absorbs yellow and blue light while reflecting green light. The wavelengths of yellow and blue light are absorbed by chlorophyll for photosynthesis, which results in the green color we perceive. Choice B is incorrect because chlorophyll absorbs yellow and blue light, not green light. Choice C is incorrect because chlorophyll does absorb green light, but it also absorbs other wavelengths, primarily yellow and blue. Choice D is incorrect because chlorophyll primarily absorbs yellow and blue light, not red light.

3. What is the purpose of phloem tissue in plant stems?

A. It conducts water up through the stem.
B. It conducts the energy of light to leaves.
C. It conducts food throughout the plant.
D. It conducts carbon dioxide throughout the plant.

Correct answer: C

Rationale: The purpose of phloem tissue in plant stems is to conduct food, particularly sugars produced in the leaves during photosynthesis, throughout the plant. The phloem transports these organic compounds to various parts of the plant where they are needed for growth and energy. Choice A is incorrect because water is primarily transported by xylem tissue, not phloem. Choice B is incorrect as the energy of light is captured by chlorophyll in the process of photosynthesis, not conducted by phloem. Choice D is incorrect because carbon dioxide is mainly absorbed through the leaves and transported to other parts of the plant through diffusion, not by phloem.

4. Which organelle contains the genetic material of the cell?

A. Golgi apparatus
B. Ribosome
C. Endoplasmic reticulum
D. Nucleus

Correct answer: D

Rationale: The correct answer is 'D: Nucleus.' The nucleus is the organelle that contains the cell's genetic material, which is the DNA. The genetic material in the nucleus controls the cell's activities and plays a crucial role in inheritance. Choices A, B, and C are incorrect because the Golgi apparatus is involved in modifying, sorting, and packaging of proteins; ribosomes are involved in protein synthesis; and endoplasmic reticulum is involved in protein and lipid synthesis and transportation, but none of them contain the genetic material of the cell.

5. 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.