HESI A2
HESI A2 Version 1 Biology Questions
Question 1 of 5
In the human life cycle, only sperm and eggs have which number of chromosomes?
Correct Answer: D
Rationale: In humans, sperm and egg cells are haploid, meaning they contain half the number of chromosomes (23) compared to diploid cells (46). This reduction in chromosome number is essential for sexual reproduction, allowing the formation of a diploid zygote upon fertilization. Haploid cells carry only one set of chromosomes, which is necessary for genetic diversity and the fusion of genetic material during fertilization.
Question 2 of 5
What structure enables sperm cells to move effectively?
Correct Answer: D
Rationale: The flagellum is a whip-like structure that is crucial for sperm cells to swim and move effectively. It provides the necessary motility for sperm, allowing them to navigate through the female reproductive tract to reach the egg for fertilization. In contrast, structures like centriole, cilium, and centrosome do not have the propelling ability required for sperm cell movement.
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
What structure in a plant cell acts as a barrier and provides support to the cell?
Correct Answer: D
Rationale: The cell wall is the correct answer. It acts as a rigid barrier that surrounds the plant cell membrane, providing structural support and protection. Plant cells have cell walls, unlike animal cells, which give them their shape and rigidity.
Question 5 of 5
In the human life cycle, only sperm and eggs have which number of chromosomes?
Correct Answer: D
Rationale: In humans, sperm and egg cells are haploid, meaning they contain half the number of chromosomes (23) compared to diploid cells (46). This reduction in chromosome number is essential for sexual reproduction, allowing the formation of a diploid zygote upon fertilization. Haploid cells carry only one set of chromosomes, which is necessary for genetic diversity and the fusion of genetic material during fertilization.