HESI A2
HESI A2 Version 1 Biology Questions
Question 1 of 5
Where in the cell does the Krebs cycle take place?
Correct Answer: A
Rationale: The Krebs cycle, also known as the citric acid cycle, occurs in the mitochondrion of eukaryotic cells. This cycle is a vital component of cellular respiration, where it is responsible for converting acetyl-CoA into ATP, NADH, and FADHā‚‚, contributing to energy production within the cell. The mitochondrion is often referred to as the powerhouse of the cell due to its role in generating energy through processes like the Krebs cycle.
Question 2 of 5
Which combination of cell cycle phase and descriptor is correct?
Correct Answer: C
Rationale: The correct answer is C. The Gā‚‚ phase is the phase before mitosis within interphase where the cell grows in size and synthesizes proteins needed for cell division. Option A incorrectly describes the S phase, which is primarily for DNA synthesis. Option B is incorrect as the doubling of chromosomes does not occur in Gā‚� phase. Option D is inaccurate because interphase encompasses Gā‚�, S, and Gā‚‚ phases, during which the cell prepares for division by increasing its mass and organelles, rather than specifically focusing on mitosis preparation.
Question 3 of 5
Which set is correctly listed for characteristic chromosome number, and most of their cells have a complete set of these chromosomes?
Correct Answer: D
Rationale: The correct order from largest to smallest is Phylum, Order, Genus, Species. In biological classification, the hierarchy of taxonomic ranks is structured such that phylum is the broadest category, followed by order, genus, and species, which is the most specific. When looking at the characteristic chromosome number, most cells have a complete set of chromosomes, and this order aligns with the genetic similarity and differences observed in organisms.
Question 4 of 5
Where in the cell does the Krebs cycle take place?
Correct Answer: A
Rationale: The Krebs cycle, also known as the citric acid cycle, occurs in the mitochondrion of eukaryotic cells. This cycle is a vital component of cellular respiration, where it is responsible for converting acetyl-CoA into ATP, NADH, and FADHā‚‚, contributing to energy production within the cell. The mitochondrion is often referred to as the powerhouse of the cell due to its role in generating energy through processes like the Krebs cycle.
Question 5 of 5
Which term means alternate forms of a gene for the same trait?
Correct Answer: B
Rationale: Alleles are different versions of a gene that can exist for a given trait. For example, a gene for flower color may have a red allele and a white allele, representing the alternate forms of that gene. Genotypes refer to the genetic makeup, while phenotypes refer to the observable traits.