which of the following is not found within a bacterial cell

HESI A2

HESI A2 Practice Test Biology

1. Which of the following is not found within a bacterial cell?

A. mitochondria
B. DNA
C. vesicles
D. ribosome

Correct answer: A

Rationale: The correct answer is A: mitochondria. Mitochondria are not found in bacterial cells. Bacterial cells lack membrane-bound organelles like mitochondria, which are commonly found in eukaryotic cells. Choices B, C, and D are all components that can be found within a bacterial cell. Bacterial cells contain DNA as their genetic material, vesicles for various cellular functions, and ribosomes for protein synthesis. Therefore, the presence of mitochondria is the distinguishing factor that is not found in bacterial cells, making option A the correct answer.

2. Three students measured the mass of a product of combustion. They recorded measurements of 14 g, 16 g, and 17 g. If the known mass of the product is 30 g, how would you describe the students’ measurements?

A. Accurate
B. Precise
C. Both accurate and precise
D. Neither accurate nor precise

Correct answer: B

Rationale: The students' measurements are precise because they are consistently close to each other. However, they are not accurate because all the measurements deviate from the known mass of the product (30 g). Accuracy refers to how close a measurement is to the true or accepted value, while precision refers to the level of agreement among repeated measurements. Since the students' measurements are consistent but do not align with the true value, they can be considered precise but not accurate. Choice A is incorrect because accuracy relates to the proximity of the measurements to the true value, which is not the case here. Choice C is incorrect because although the measurements are precise, they are not accurate. Choice D is incorrect because the measurements are precise as they show good agreement with each other, even though they are not accurate.

3. How is the plasma membrane arranged?

A. In a single layer made of proteins
B. In a double layer made of proteins
C. In a single layer of phospholipids
D. In a double layer of phospholipids

Correct answer: D

Rationale: The plasma membrane is arranged in a double layer of phospholipids, known as a phospholipid bilayer. This structure consists of two layers of phospholipid molecules with hydrophilic heads facing the exterior and hydrophobic tails facing the interior, providing a semipermeable barrier for the cell. Choice A is incorrect because the plasma membrane is not made of a single layer of proteins. Choice B is incorrect as the double layer is composed of phospholipids, not proteins. Choice C is incorrect as the plasma membrane is not made of a single layer of phospholipids but rather a double layer.

4. Why is the nucleus important in a cell?

A. It stores the DNA
B. It supports the cell
C. It makes protein
D. It makes energy out of food

Correct answer: A

Rationale: The nucleus is important in a cell because it stores the DNA, which contains the genetic information necessary for the cell's function and replication. This genetic material controls the cell's activities and characteristics. Choices B, C, and D are incorrect because supporting the cell, making proteins, and producing energy are functions typically associated with other cell organelles like the cytoskeleton, ribosomes, and mitochondria, respectively.

5. Which of the following is not a product of the Krebs cycle?

A. carbon dioxide
B. oxygen
C. adenosine triphosphate (ATP)
D. energy carriers

Correct answer: B

Rationale: The correct answer is B: oxygen. Oxygen is not a product of the Krebs cycle. During the Krebs cycle, carbon dioxide, adenosine triphosphate (ATP), and energy carriers like NADH and FADH2 are produced. Carbon dioxide is a byproduct of the cycle, ATP is a form of energy produced, and energy carriers play a crucial role in transferring energy within the cell. Therefore, oxygen is the only option that is not a product of the Krebs cycle, making it the correct answer.