HESI RN
Biology Practice Test
1. In the hierarchical organizational system, which of these is the most restrictive category?
- A. Genus
- B. Class
- C. Kingdom
- D. Species
Correct answer: D
Rationale: In the biological classification hierarchy, species is the most specific level, defining individual organisms that can interbreed. While genus, class, and kingdom are also categories in the hierarchy, they are broader and encompass a wider range of organisms compared to species. Genus groups together similar species, class groups similar orders, and kingdom is the broadest category grouping together similar phyla.
2. In DNA, the nucleotide base adenine always binds with which of the following?
- A. Guanine
- B. Uracil
- C. Thymine
- D. Cytosine
Correct answer: C
Rationale: The correct answer is C: Thymine. In DNA, adenine always pairs with thymine, forming a base pair held together by hydrogen bonds. Guanine pairs with cytosine. Uracil is found in RNA, not DNA. Cytosine pairs with guanine. Therefore, option C is the correct pairing for adenine in DNA.
3. What is the primary method of asexual reproduction used by most bacteria?
- A. Meiosis
- B. Mitosis
- C. Binary fission
- D. Interphase
Correct answer: C
Rationale: The correct answer is C: Binary fission. This is the main process through which most bacteria reproduce asexually. During binary fission, a single cell divides into two identical cells, each containing a copy of the genetic material. Choices A and B, meiosis and mitosis, are processes involved in sexual reproduction and are not used by bacteria for asexual reproduction. Choice D, interphase, is a stage of the cell cycle where the cell prepares for division and is not a method of reproduction.
4. Protein synthesis begins with a process known as transcription. What is produced during this process?
- A. A codon
- B. A DNA helix
- C. A DNA strand
- D. An RNA strand
Correct answer: D
Rationale: The correct answer is D: An RNA strand. During transcription, the DNA template is used to produce an RNA strand, not a codon, DNA helix, or another DNA strand. A codon is a sequence of nucleotides that specifies a particular amino acid during translation, not produced during transcription. A DNA helix refers to the double-stranded structure of DNA, which is not produced during transcription. Another DNA strand is not produced during transcription since the process involves creating an RNA copy of a specific gene.
5. What function does cholesterol, a phospholipid, serve within the cell membrane?
- A. It builds up fats to make the structure more flexible
- B. It allows protein channels to form
- C. It makes the structure very rigid and impermeable
- D. It stabilizes the membrane structure
Correct answer: D
Rationale: Cholesterol helps to maintain the fluidity and stability of the cell membrane by fitting between the phospholipid molecules. Choice A is incorrect because cholesterol does not build up fats in the cell membrane. Choice B is incorrect as protein channels are formed by proteins, not cholesterol. Choice C is incorrect as cholesterol actually helps regulate the fluidity of the membrane, making it less rigid and more permeable.
Similar Questions
Access More Features
HESI RN Basic
$69.99/ 30 days
- 5,000 Questions with answers
- All HESI courses Coverage
- 30 days access
HESI RN Premium
$149.99/ 90 days
- 5,000 Questions with answers
- All HESI courses Coverage
- 30 days access