HESI A2
HESI A2 Biology Practice Test
1. Genes control heredity in man and other organisms. This gene is ___
- A. A segment of DNA
- B. A bead-like structure on the chromosomes
- C. A protein molecule
- D. A segment of RNA
Correct answer: A
Rationale: Genes are sections of DNA that contain instructions for building and operating living organisms. These sections of DNA contain the genetic information that is passed on from one generation to the next. Genes are composed of specific sequences of nucleotides within the DNA molecule. Therefore, genes are best described as segments of DNA. Choice A is correct. Choice B is incorrect because genes are not bead-like structures on chromosomes but specific sequences of DNA. Choice C is incorrect because genes are not protein molecules but rather sequences of nucleotides. Choice D is incorrect because genes are not segments of RNA but DNA.
2. The fur color in a population of dogs is controlled by two alleles: black (B) and tan (b). The black allele exhibits complete dominance. If the phenotype of the dog is tan fur, what is its genotype?
- A. BB
- B. Bb
- C. bb
- D. Not enough information
Correct answer: C
Rationale: The correct answer is C: "bb." Since tan fur is the recessive trait controlled by the allele 'b,' the only possible genotype for a dog with tan fur is 'bb.' If a dog had the genotype 'BB' or 'Bb,' the dominant trait (black fur) would be expressed, not tan fur. Choice D, 'Not enough information,' is incorrect because based on the information provided, we can deduce the genotype of a dog with tan fur.
3. Which is true of gametes?
- A. They are diploid cells
- B. They are haploid cells
- C. They are somatic
- D. A & C are true
Correct answer: B
Rationale: Gametes are sex cells (sperm and eggs) that are involved in sexual reproduction. They are haploid cells, meaning they have half the number of chromosomes (n) compared to diploid cells. This is necessary for the formation of a diploid zygote when two gametes unite during fertilization. Somatic cells are non-reproductive cells in the body, so they are not gametes. Choice A is incorrect because gametes are not diploid but haploid. Choice C is incorrect because gametes are not somatic cells.
4. Where is the genetic information of a eukaryotic cell stored?
- A. Mitochondria
- B. Nucleus
- C. Golgi Apparatus
- D. Cytoplasm
Correct answer: B
Rationale: The correct answer is B: Nucleus. In eukaryotic cells, genetic information (DNA) is stored in the nucleus. This organelle acts as the control center of the cell, housing the DNA and regulating gene expression. Choices A, C, and D are incorrect because the genetic information is not stored in the mitochondria, Golgi Apparatus, or cytoplasm. The mitochondria are responsible for energy production, the Golgi Apparatus is involved in protein processing and packaging, and the cytoplasm is where various cellular activities take place, but none of these organelles store the genetic information.
5. Choose the two bases that have two carbon rings:
- A. Adenine
- B. Cytosine
- C. Thymine
- D. Guanine
Correct answer: A
Rationale: Adenine and guanine have two carbon rings and are known as purines. These bases are found in nucleic acids such as DNA and RNA. Adenine (option A) and guanine (option D) are the correct choices as they both have two carbon rings in their molecular structure. Cytosine (option B) and thymine (option C) have a single carbon ring each, making them incorrect choices for bases with two carbon rings.
Similar Questions
Access More Features
HESI A2 Basic
$99/ 30 days
- 3,000 Questions with answers
- 30 days access
HESI A2 Premium
$149.99/ 90 days
- Actual HESI A2 Questions
- 3,000 questions with answers
- 90 days access