HESI RN
Biology Practice Test
1. The Punnett square shows that one parent carries the recessive gene for a cleft chin (c) while the other parent does not. What percentage of the parents' offspring is predicted to have a cleft chin?
- A. 25%
- B. 50%
- C. 0%
- D. 75%
Correct answer: C
Rationale: The correct answer is 0%. If one parent carries the recessive gene for a cleft chin while the other parent does not, none of the offspring will express the recessive phenotype. This is because in order for a child to have a cleft chin, they would need to inherit the recessive gene from both parents. Therefore, although the offspring could be carriers of the gene, none are predicted to have a cleft chin. Choices A, B, and D are incorrect because the presence of the recessive gene in one parent and its absence in the other would not result in any offspring showing the cleft chin trait.
2. Which of the following organelles is known as the cell's digestion center?
- A. Chloroplasts
- B. Mitochondria
- C. Lysosomes
- D. Ribosomes
Correct answer: C
Rationale: The correct answer is C: Lysosomes. Lysosomes contain enzymes that break down waste materials and cellular debris within the cell, making them the cell's digestion center. Choice A, Chloroplasts, are responsible for photosynthesis. Choice B, Mitochondria, are the powerhouse of the cell, generating energy. Choice D, Ribosomes, are involved in protein synthesis. Therefore, Lysosomes are specifically known for their role in digestion within the cell.
3. In meiosis, the chromosome number is reduced from:
- A. 46 to 23
- B. 46 to 33
- C. 28 to 14
- D. 24 to 12
Correct answer: A
Rationale: The correct answer is A: "46 to 23." In meiosis, the chromosome number is reduced by half to form gametes for sexual reproduction. In humans, where the diploid chromosome number is 46, meiosis results in haploid cells with 23 chromosomes. Choices B, C, and D are incorrect because they do not represent the correct reduction in chromosome number during meiosis.
4. Water is a polar molecule that can be:
- A. cohesive and corrosive
- B. cohesive and adhesive
- C. electrostatic and ionic
- D. repellent and attractive
Correct answer: B
Rationale: Water is a polar molecule due to an uneven distribution of electrons, allowing it to form hydrogen bonds. This property makes water both cohesive (attracted to itself) and adhesive (attracted to other substances). Choice A is incorrect because water is not corrosive; rather, it is a solvent. Choices C and D are incorrect as they do not describe the cohesive and adhesive properties of water.
5. Which of the following options is the term used to represent alternative versions of a gene?
- A. Alleles
- B. Binary fission
- C. Heterozygous
- D. Homozygous
Correct answer: A
Rationale: The correct answer is A: Alleles. Alleles are different forms of a gene that can exist at a specific locus on a chromosome. They represent variations in a gene's DNA sequence. Choices B, C, and D are incorrect. Binary fission is a form of asexual reproduction in single-celled organisms, while heterozygous and homozygous refer to different combinations of alleles in an individual, not the alternative versions of a gene.
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