HESI A2
HESI A2 Practice Test Biology
1. Which of the following is necessary for cell diffusion?
- A. water
- B. membrane
- C. ATP
- D. gradient
Correct answer: D
Rationale: The correct answer is 'gradient.' In cell diffusion, substances move from an area of high concentration to an area of low concentration, driven by the concentration gradient. This process does not require water, membrane, or ATP specifically. Water can aid in the movement of substances, but it is not necessary for diffusion itself. The membrane is involved in regulating diffusion but is not a requirement for the process. ATP is not directly involved in simple diffusion processes; instead, it is more related to active transport mechanisms. Therefore, the concentration gradient is essential for cell diffusion to occur.
2. Cells that line the inner or outer surfaces of organs or body cavities are often linked together by intimate physical connections. These connections are referred to as ______.
- A. Separate desmosomes
- B. Ronofilaments
- C. Tight junctions
- D. Fascia adherens
Correct answer: C
Rationale: The correct answer is C: Tight junctions. Tight junctions, also known as zonula occludens, are the intimate physical connections between cells that line the inner or outer surfaces of organs or body cavities. These junctions form a virtually impermeable barrier to fluid, creating a tight seal between the cells. This helps in maintaining the integrity and function of the tissue as well as regulating the movement of substances across the cell layer. Choice A, Separate desmosomes, are cell structures that provide strong adhesion between cells but do not create a barrier to fluid. Choice B, Ronofilaments, is not a term used to describe the connections between cells. Choice D, Fascia adherens, are another type of cell junction involved in cell adhesion, but they are different from tight junctions in terms of their structure and function.
3. Which of the following are found both in open and closed circulatory systems?
- A. Arteries
- B. Red blood cells
- C. Capillaries
- D. Immune cells
Correct answer: C
Rationale: The correct answer is C, Capillaries. Capillaries are found in both open and closed circulatory systems. Capillaries are small blood vessels that connect arteries and veins, allowing for the exchange of nutrients and wastes between the blood and tissues. They are essential components of circulatory systems regardless of whether they are open or closed. Arteries (Choice A) are not found in open circulatory systems, as these systems lack distinct arteries and veins. Red blood cells (Choice B) are present in the blood but are not exclusive to either open or closed circulatory systems. Immune cells (Choice D) are not specific components of circulatory systems, as they are part of the immune system.
4. Patient A, who weighs 68 kilograms, steps onto a scale 20 times. The scale consistently weighs Patient A as 75 kilograms. What is true of the measurement?
- A. It is valid, but not reliable.
- B. It is reliable, but not valid.
- C. It is both valid and reliable.
- D. It is neither reliable nor valid.
Correct answer: B
Rationale: The correct answer is B: 'It is reliable, but not valid.' The measurement is reliable because it consistently provides the same result (75 kg). However, it is not valid because it does not accurately reflect the true weight of Patient A (68 kg). Choice A is incorrect because if the scale consistently shows the same weight (75 kg), it is reliable. Choice C is incorrect because although the scale is consistent, the measurement does not reflect the true weight, making it not valid. Choice D is incorrect as the measurement is reliable but lacks validity.
5. Prokaryotic cells:
- A. Have a nucleus
- B. Have a capsule
- C. Have membrane-bound organelles
- D. Cannot move on their own
Correct answer: B
Rationale: Prokaryotic cells do not have a nucleus or membrane-bound organelles. One characteristic feature of prokaryotic cells is the presence of a capsule, which is a protective layer outside the cell wall. This capsule helps the prokaryotic cell adhere to surfaces, evade the host immune system, and protect against desiccation. Choice A is incorrect because prokaryotic cells lack a nucleus. Choice C is incorrect as prokaryotic cells do not have membrane-bound organelles. Choice D is incorrect as prokaryotic cells can move using structures like flagella or pili.
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