Nokea
Which of the following best defines the term amphoteric?
- A. A substance that conducts electricity due to ionization when dissolved in a solvent
- B. A substance that can act as an acid or a base depending on the properties of the solute
- C. A substance that, according to the Br¸nsted-Lowry Acid-Base Theory, is a proton-donor
- D. A substance that donates its proton and forms its conjugate base in a neutralization reaction
Correct Answer: B
Rationale: An amphoteric substance can act as both an acid or a base depending on the environment. It can donate a proton (act as an acid) or accept a proton (act as a base), showing versatility in its behavior. Choice A is incorrect as it describes an electrolyte rather than an amphoteric substance. Choice C is incorrect as it defines an acid based on the Br¸nsted-Lowry Acid-Base Theory. Choice D is incorrect as it specifically refers to a substance donating a proton in a neutralization reaction, not capturing the dual behavior of an amphoteric substance.
You may also like to solve these questions
What is the process of cell division in somatic (most body) cells called?
- A. Mitosis
- B. Meiosis
- C. Respiration
- D. Cytogenesis
Correct Answer: A
Rationale: Mitosis is the correct answer. It is the process of cell division in somatic cells, leading to the formation of two identical daughter cells with the same number of chromosomes as the parent cell. Meiosis, on the other hand, is the type of cell division that occurs in sex cells, leading to the formation of gametes with half the number of chromosomes. Respiration is a completely different biological process related to energy production, and cytogenesis is not a recognized term for cell division.
What is one feature that both prokaryotes and eukaryotes have in common?
- A. A plasma membrane
- B. A nucleus enclosed by a membrane
- C. Organelles
- D. A nucleoid
Correct Answer: A
Rationale: The correct answer is A: A plasma membrane. Both prokaryotes and eukaryotes share the characteristic of having a plasma membrane that surrounds the cell. While eukaryotes also possess a nucleus enclosed by a membrane and various organelles, prokaryotes lack a nucleus and membrane-bound organelles. The plasma membrane, however, is a universal feature found in all cells, regardless of their classification as prokaryotic or eukaryotic. Choice B is incorrect because only eukaryotes have a nucleus enclosed by a membrane. Choice C is incorrect because prokaryotes have limited organelles compared to eukaryotes. Choice D is incorrect as a nucleoid is a region in prokaryotic cells where the genetic material is located, not a common feature shared with eukaryotes.
The acceleration of a falling object due to gravity has been proven to be 9.8 m/s^2. A scientist drops a cactus four times and measures the acceleration with an accelerometer and gets the following results: 9.79 m/s^2, 9.81 m/s^2, 9.80 m/s^2, and 9.78 m/s^2. Which of the following accurately describes the measurements?
- A. They're both accurate and precise.
- B. They're accurate but not precise.
- C. They're precise but not accurate.
- D. They're neither accurate nor precise.
Correct Answer: A
Rationale: The measurements are close to the true value of 9.8 m/s^2 and are also close to each other, indicating both accuracy and precision. Accuracy refers to how close a measurement is to the true value, while precision refers to how close repeated measurements are to each other. In this case, the measurements are accurate because they are close to the accepted value of 9.8 m/s^2, and they are precise because they are clustered closely around each other. Therefore, choice A, 'They're both accurate and precise,' is the correct answer. Choice B is incorrect because the measurements are precise as they are close to each other, but they are also accurate as they are close to the true value. Choice C is incorrect because the measurements are accurate as they are close to the true value, and choice D is incorrect because the measurements exhibit both accuracy and precision in this scenario.
What is an alteration in the normal gene sequence called?
- A. DNA mutation
- B. Gene migration
- C. Polygenic inheritance
- D. Incomplete dominance
Correct Answer: A
Rationale: A DNA mutation is the correct term used to describe an alteration in the normal gene sequence. It refers to changes in the DNA sequence that can result in different traits or characteristics. Gene migration involves the movement of genes between populations, polygenic inheritance refers to the inheritance of traits controlled by multiple genes, and incomplete dominance is a pattern of inheritance where neither allele is dominant.
How do organisms maintain homeostasis?
- A. By increasing their body temperature, blood pH, and fluid balance.
- B. By undergoing biochemical processes and absorbing energy to increase entropy.
- C. By undergoing biochemical processes to maintain the order of their external environment.
- D. By using free energy and matter via biochemical processes to work against entropy.
Correct Answer: D
Rationale: Organisms maintain homeostasis by utilizing free energy and matter through biochemical processes to counteract entropy, which helps in preserving internal stability. This process involves maintaining a balance within the organism's internal environment despite external changes, ensuring proper functioning and survival. Choice A is incorrect because increasing body temperature, blood pH, and fluid balance alone do not define the comprehensive process of maintaining homeostasis. Choice B is incorrect as absorbing energy to increase entropy goes against the concept of maintaining internal stability. Choice C is incorrect as maintaining the order of the external environment does not directly contribute to the organism's internal stability and balance.