what is the difference between dna and rna
Logo

Nursing Elites

HESI RN

Biology Test

1. What is the difference between DNA and RNA?

Correct answer: B

Rationale: The correct answer is B. DNA has one less oxygen atom in its sugar molecule (deoxyribose) compared to RNA, which has a ribose sugar. Choice A is incorrect because RNA does not have an extra phosphate group. Choice C is incorrect as RNA actually has one more oxygen atom than DNA. Choice D is incorrect as DNA and RNA have different sugar molecules, with DNA having deoxyribose and RNA having ribose.

2. Which of the following is not one of the four nitrogenous bases that make up the DNA structure?

Correct answer: C

Rationale: The correct answer is C: Uracil. Uracil is found in RNA, not DNA. The four nitrogenous bases in DNA are adenine, thymine, cytosine, and guanine. Choice A, Adenine, is a nitrogenous base in DNA. Choice B, Guanine, is another nitrogenous base in DNA. Choice D, Thymine, is also one of the four nitrogenous bases in DNA. Therefore, the correct answer is Uracil (Choice C).

3. The term pleiotropy is best defined as which of the following?

Correct answer: B

Rationale: Pleiotropy is best defined as one gene influencing multiple, seemingly unrelated phenotypic traits. This phenomenon showcases the multifunctionality of genes, where a single gene can have effects on various aspects of an organism's phenotype. Choices A, C, and D do not accurately capture the concept of pleiotropy. Option A refers to gene expression, not pleiotropy. Option C describes genetic interactions but not in the context of pleiotropy. Option D talks about missing genes, which is unrelated to the definition of pleiotropy.

4. Where can ribosomes be found inside a cell?

Correct answer: A

Rationale: Ribosomes can be found attached to the endoplasmic reticulum (ER) or free-floating in the cytoplasm. The correct answer is A because ribosomes are responsible for synthesizing proteins and are commonly found on the ER or in the cytoplasm. Choice B is incorrect because ribosomes are not typically located within the cellular membrane. Choice C is incorrect as ribosomes are not attached to the Golgi apparatus; instead, they are involved in protein synthesis. Choice D is incorrect as ribosomes are not found within the nucleus but rather in the cytoplasm or attached to the ER.

5. In meiosis, the chromosome number is reduced from:

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.

Similar Questions

What is the most significant contributor to cellular function?
Why does ice have the capability of floating on water?
Which of the following do prokaryotic cells lack?
What cell structure is responsible for efficiently packaging DNA into a small volume to fit into the nucleus of a cell and protect the DNA structure and sequence?
What is the main objective of the translation stage of protein synthesis?

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

Other Courses