HESI A2
Biology HESI A2 Practice Exam
1. Which of these is not an example of a lipid?
- A. Butter
- B. Wax
- C. Canola oil
- D. Honey
Correct answer: D
Rationale: Honey is not an example of a lipid because lipids are fat-related molecules that are insoluble in water, while honey is a natural sweet substance made by bees and primarily consists of sugars such as glucose and fructose. Butter, wax, and canola oil are examples of lipids as they are all composed of fat-related molecules that do not dissolve in water.
2. Which of the following bases is not present in RNA?
- A. Adenine
- B. Thymine
- C. Uracil
- D. Cytosine
Correct answer: B
Rationale: Thymine is not present in RNA. RNA uses uracil as one of its bases, which pairs with adenine. In RNA, adenine does not pair with thymine as in DNA. Cytosine and guanine are the other two bases found in both RNA and DNA.
3. Which type of passive transport uses proteins that change shape to move a target molecule through the membrane?
- A. Diffusion
- B. Carrier proteins
- C. Channel proteins
- D. None of the above
Correct answer: B
Rationale: The correct answer is B: Carrier proteins. Carrier proteins are involved in facilitated diffusion, a type of passive transport where specific target molecules are moved across the membrane with the help of proteins that change shape. These carrier proteins bind to the target molecule on one side of the membrane, undergo a conformational change, and then release the molecule on the other side. This process is crucial for the selective transport of certain molecules that cannot pass through the membrane by simple diffusion. Choices A and C are incorrect because diffusion and channel proteins do not involve proteins that change shape to transport target molecules selectively. Choice D is incorrect as carrier proteins fit the description provided in the question.
4. Beeswax is an example of what kind of molecule?
- A. Lipid
- B. Carbohydrate
- C. Protein
- D. Nucleic acid
Correct answer: A
Rationale: Beeswax is primarily composed of esters of long-chain aliphatic alcohols and fatty acids, making it a type of lipid. Lipids are a diverse group of molecules that are hydrophobic in nature and have important functions in energy storage, signaling, and forming cellular membranes. Beeswax's chemical composition and properties categorize it as a lipid rather than a carbohydrate, protein, or nucleic acid. Carbohydrates are composed of sugars, proteins are made up of amino acids, and nucleic acids consist of nucleotides; none of which match the chemical composition of beeswax.
5. Which organelle contains the genetic material of the cell?
- A. Golgi apparatus
- B. Ribosome
- C. Endoplasmic reticulum
- D. Nucleus
Correct answer: D
Rationale: The correct answer is 'D: Nucleus.' The nucleus is the organelle that contains the cell's genetic material, which is the DNA. The genetic material in the nucleus controls the cell's activities and plays a crucial role in inheritance. Choices A, B, and C are incorrect because the Golgi apparatus is involved in modifying, sorting, and packaging of proteins; ribosomes are involved in protein synthesis; and endoplasmic reticulum is involved in protein and lipid synthesis and transportation, but none of them contain the genetic material of the cell.
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