HESI RN
Biology Practice Test
1. Which of the following do prokaryotic cells lack?
- A. A cell membrane
- B. Genetic material
- C. Cytoplasm
- D. Membrane-bound organelles
Correct answer: D
Rationale: The correct answer is D: Prokaryotic cells lack membrane-bound organelles, such as mitochondria or a nucleus, distinguishing them from eukaryotic cells. Prokaryotic cells do have genetic material, a cell membrane, and cytoplasm. Choice A is incorrect because prokaryotic cells do have a cell membrane, which is essential for maintaining cell structure and regulating what enters and exits the cell. Choice B is incorrect because prokaryotic cells contain genetic material, typically in the form of a single circular chromosome. Choice C is incorrect because prokaryotic cells have cytoplasm, where various cellular activities take place.
2. Which of the following is a group of three RNA nucleotides?
- A. A stop codon
- B. A codon
- C. An anticodon
- D. tRNA
Correct answer: B
Rationale: The correct answer is B - A codon. A codon is a sequence of three RNA nucleotides that specifies a particular amino acid or a stop signal during protein synthesis. Choice A, a stop codon, is a sequence of three nucleotides that signals the termination of protein synthesis. Choice C, an anticodon, is a group of three nucleotides found in tRNA that pairs with the complementary codon in mRNA. Choice D, tRNA, stands for transfer RNA, which is a type of RNA that carries amino acids to the ribosome during protein synthesis.
3. Asexual reproduction is a type of reproduction by which offspring arise from:
- A. Two identical cells
- B. A single cell
- C. Two cells
- D. Four daughter cells
Correct answer: B
Rationale: Asexual reproduction is a type of reproduction where a single parent cell divides to produce genetically identical offspring. The correct answer is 'B: A single cell' because asexual reproduction does not involve the fusion of two cells. Choice A ('Two identical cells') is incorrect because asexual reproduction does not involve two cells. Choice C ('Two cells') is incorrect because asexual reproduction typically involves only one parent cell. Choice D ('Four daughter cells') is incorrect because asexual reproduction does not necessarily involve the production of four daughter cells.
4. Which of the following is responsible for the synthesis of carbohydrates, lipids, and steroid hormones?
- A. Smooth endoplasmic reticulum (ER)
- B. Rough endoplasmic reticulum (ER)
- C. Golgi apparatus
- D. Ribosomes
Correct answer: A
Rationale: The smooth endoplasmic reticulum (ER) is the correct answer. It is responsible for the synthesis of lipids, including steroids, and also plays a role in carbohydrate metabolism. The rough endoplasmic reticulum (ER) is involved in protein synthesis and processing, not lipid or carbohydrate synthesis. The Golgi apparatus is responsible for modifying, sorting, and packaging of proteins and lipids, but not for their synthesis. Ribosomes are the cellular organelles responsible for protein synthesis, not lipid or carbohydrate synthesis.
5. Which of the following organelles is the site of cellular respiration?
- A. Nucleus
- B. Mitochondria
- C. Lysosomes
- D. Ribosomes
Correct answer: B
Rationale: The correct answer is B: Mitochondria. Mitochondria are known as the powerhouse of the cell because they generate most of the cell's supply of ATP through cellular respiration. The other organelles listed, such as the nucleus (choice A), lysosomes (choice C), and ribosomes (choice D), do not play a direct role in cellular respiration. The nucleus contains genetic material, lysosomes are involved in digestion and waste removal, and ribosomes are responsible for protein synthesis.
Similar Questions
Access More Features
HESI RN Basic
$89/ 30 days
- 50,000 Questions with answers
- All HESI courses Coverage
- 30 days access @ $89
HESI RN Premium
$149.99/ 90 days
- 50,000 Questions with answers
- All HESI courses Coverage
- 30 days access @ $149.99