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HESI A2

HESI A2 Math Practice

1. Multiply: 3/4 × 1/3.

A. 1/4
B. 1/3
C. 3/5
D. 3/8

Correct answer: A

Rationale: To multiply fractions, multiply the numerators together and the denominators together. In this case, 3/4 × 1/3 = (3 × 1) / (4 × 3) = 3/12 = 1/4. Therefore, the correct answer is A: 1/4. Choices B (1/3), C (3/5), and D (3/8) are incorrect because they do not result from the correct multiplication of the given fractions.

2. Which type of radiation emits helium ions and can be stopped by a piece of paper?

A. Beta radiation
B. Alpha radiation
C. Gamma radiation
D. X-ray radiation

Correct answer: B

Rationale: Alpha radiation emits helium ions, which are helium nuclei without electrons, making them positively charged. These ions are relatively large and heavy compared to beta and gamma radiation. Due to their size and charge, alpha particles interact strongly with matter and are easily stopped. A piece of paper or even human skin can effectively block alpha radiation. Therefore, alpha radiation is the type of radiation that can be stopped by a piece of paper. Beta radiation consists of fast-moving electrons and can penetrate further into materials than alpha radiation, thus not stopped by a piece of paper. Gamma radiation is highly penetrating and requires dense materials like lead or concrete to block it effectively. X-ray radiation, similar to gamma radiation, is also highly penetrating and cannot be stopped by a piece of paper.

3. Which names a final step in protein synthesis?

A. DNA unzips.
B. Amino acids bond.
C. Transfer RNA bonds to messenger RNA.
D. Messenger RNA moves to ribosomes.

Correct answer: B

Rationale: The final step in protein synthesis is when amino acids bond together to form a protein chain. This process occurs during translation, where transfer RNA (tRNA) brings specific amino acids to the ribosome, and the ribosome catalyzes the formation of peptide bonds between the amino acids. This step ultimately leads to the synthesis of a complete protein based on the instructions from messenger RNA (mRNA). Choice A ('DNA unzips') is incorrect as it refers to the initiation of transcription, not the final step of protein synthesis. Choice C ('Transfer RNA bonds to messenger RNA') is incorrect as it describes the process of translation initiation rather than the final step. Choice D ('Messenger RNA moves to ribosomes') is also incorrect as mRNA is already present at the ribosomes throughout the translation process, not just in the final step.

4. What does Torpid mean?

A. Energetic
B. Sluggish
C. Fast
D. Slow

Correct answer: B

Rationale: The correct answer is B: 'Sluggish.' Torpid means being slow or inactive. Choice A, 'Energetic,' is the opposite of torpid. Choice C, 'Fast,' is not synonymous with torpid as it refers to quickness rather than sluggishness. Choice D, 'Slow,' is somewhat related to torpid but does not fully capture the inactive aspect of the term.

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.