HESI RN
Biology Test Questions
Question 1 of 5
Why does ice have the capability of floating on water?
Correct Answer: D
Rationale: The correct answer is D. Ice forms a lattice structure when it freezes, which makes it less dense than liquid water, allowing it to float. Choice A is incorrect because viscosity refers to a fluid's resistance to flow and is not related to ice floating. Choice B is incorrect as ice and liquid water have the same chemical composition (H2O). Choice C is incorrect because the high specific heat of water is not the reason why ice floats.
Question 2 of 5
Binary fission is a type of asexual reproduction. Which of the following occurs during the binary fission process?
Correct Answer: A
Rationale: The correct answer is A. In binary fission, the chromosomes bind to the plasma membrane before the cell splits into two. This initial step ensures that each daughter cell receives a complete set of genetic material. Choice B is incorrect because the spindle apparatus is characteristic of eukaryotic cell division (mitosis), not prokaryotic binary fission. Choice C is incorrect as chromosomes do not necessarily gather in the center of the cell during binary fission. Choice D is incorrect because the chromosomes do not begin to separate in binary fission; they replicate and then move to opposite ends of the cell before division.
Question 3 of 5
Who discovered the basic principles of genetics using garden peas?
Correct Answer: B
Rationale: The correct answer is B, Mendel. Gregor Mendel is known as the father of genetics for his groundbreaking work with pea plants. He discovered the basic principles of heredity through his experiments, establishing the foundation of modern genetics. Choice A, Curie, is incorrect as Marie Curie was a physicist and chemist known for her pioneering research on radioactivity. Choice C, Hawking, is incorrect as Stephen Hawking was a theoretical physicist known for his work on black holes and cosmology. Choice D, Galileo, is incorrect as Galileo Galilei was an astronomer and physicist renowned for his contributions to the scientific revolution, particularly in astronomy.
Question 4 of 5
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.
Question 5 of 5
What is the most important function of carbohydrates?
Correct Answer: A
Rationale: The most important function of carbohydrates is to store and provide energy for the body through metabolic processes. Carbohydrates are broken down into glucose, which is used as the primary source of energy for various cellular functions. Choice B is incorrect because amino acids are the building blocks of proteins, not directly created by carbohydrates. Choice C is incorrect as the regulation of body temperature is primarily controlled by mechanisms such as sweating and shivering, not carbohydrates. Choice D is incorrect as insulation of body organs against shock is mainly provided by adipose tissue, not carbohydrates.