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. How many chromosomes do sperm and egg produce in meiosis?

A. 23
B. 46
C. 25
D. 50

Correct answer: A

Rationale: During meiosis, sperm and egg cells produce half the number of chromosomes found in somatic cells. Each contributes 23 chromosomes, which combine to form a zygote with a total of 46 chromosomes. Choice B (46) is incorrect because this is the number of chromosomes produced in mitosis, not meiosis. Choices C (25) and D (50) are also incorrect as they do not align with the chromosome count in sex cells during meiosis.

3. What organelle is responsible for packaging, processing, and shipping?

A. Nucleus
B. Golgi Apparatus
C. Endoplasmic Reticulum
D. Ribosomes

Correct answer: B

Rationale: The Golgi Apparatus is the correct answer. It is responsible for packaging, processing, and shipping proteins and lipids within the cell. The nucleus houses genetic material, the endoplasmic reticulum is involved in protein synthesis and lipid metabolism, and ribosomes are responsible for protein synthesis. Therefore, choices A, C, and D are not the correct answers for the functions of packaging, processing, and shipping.

4. Why is yeast used to make bread rise?

A. It engages in photosynthesis, which produces oxygen gas.
B. Carbon dioxide forms while yeast carries out photosynthesis.
C. Yeast carries out fermentation, producing ethanol and carbon dioxide.
D. Yeast breathes in oxygen and produces carbon dioxide through aerobic respiration.

Correct answer: C

Rationale: Yeast is used to make bread rise because it carries out fermentation, producing carbon dioxide gas. The carbon dioxide gas gets trapped in the dough, causing it to rise and create a fluffy texture in the bread. Choices A, B, and D are incorrect because yeast does not engage in photosynthesis, so it does not produce oxygen gas, does not carry out photosynthesis to form carbon dioxide, and does not produce carbon dioxide through aerobic respiration. Yeast's fermentation process is essential for bread rising.

5. The procedure to focus an image using a compound microscope involves

A. Adjusting the coarse adjustment each time a new magnification is selected
B. Adjusting the fine adjustment each time a new magnification is selected
C. Adjusting the stage each time a new magnification is selected
D. All of the above

Correct answer: B

Rationale: When using a compound microscope, it is essential to adjust the fine adjustment knob each time you switch to a new magnification level. The fine adjustment knob allows for precise focusing on the specimen at different magnifications, ensuring a clear and sharp image. The coarse adjustment knob is typically used only at the lower magnification settings to bring the image into view roughly. Adjusting the stage may be necessary based on the size and thickness of the specimen, but it does not need to be done every time a new magnification is selected. Therefore, option B is the correct choice as it focuses on the key aspect of precise focusing during magnification changes.