Nokea
What is the fluid-filled, jelly-like substance within the cell that suspends the organelles called?
- A. Nucleus
- B. Cytoplasm
- C. Plasma membrane
- D. Golgi apparatus
Correct Answer: B
Rationale: The correct answer is B, cytoplasm. Cytoplasm is the fluid-filled, jelly-like substance within the cell that suspends the organelles. The nucleus, not the correct answer, is the organelle that contains the cell's genetic material. The plasma membrane, another incorrect choice, is the outer boundary of the cell that regulates what enters and exits the cell. The Golgi apparatus, also an incorrect choice, is an organelle involved in processing and packaging proteins.
You may also like to solve these questions
Which of the following accurately describes saltatory conduction?
- A. It is faster than normal nerve conduction
- B. It occurs from one node of Ranvier to the next
- C. It only occurs in myelinated neurons
- D. All of the above
Correct Answer: D
Rationale: The correct answer is D, 'All of the above.' Saltatory conduction is faster than normal nerve conduction, occurs from one node of Ranvier to the next, and is exclusive to myelinated neurons. This form of conduction allows for the rapid transmission of nerve impulses by the action potential jumping between the nodes of Ranvier in myelinated neurons, enhancing the efficiency of signal propagation along the axon. Choice A is correct as saltatory conduction is indeed faster than normal conduction. Choice B is accurate as it describes the mechanism of conduction 'jumping' from one node of Ranvier to the next. Choice C is correct because saltatory conduction occurs specifically in myelinated neurons where the myelin sheath insulates the axon except at the nodes of Ranvier, facilitating faster transmission of nerve impulses.
During a scientific investigation, what is intentionally changed or manipulated?
- A. The dependent variable.
- B. The control.
- C. The hypothesis.
- D. The independent variable.
Correct Answer: D
Rationale: During a scientific investigation, the independent variable is intentionally changed or manipulated by the researcher to observe its impact or effect on the dependent variable. The independent variable is the one being tested or studied to see how it influences the dependent variable. In contrast, the dependent variable is the outcome or response that is measured in an experiment and is expected to change as a result of the manipulation of the independent variable. Choices A, B, and C are not directly altered during a scientific investigation but play different roles in the research process. Therefore, the correct answer is D - the independent variable.
An uncharged atom has an electron configuration of 1s² 2s² 2pⶠ3s² and a mass number of 14. How many protons does it have?
- A. 14
- B. 6
- C. 8
- D. 12
Correct Answer: B
Rationale: The number of protons in an atom is determined by the atomic number, which is equal to the number of protons in the nucleus. The electron configuration given corresponds to carbon (C) with 6 protons. The atomic number of an element is the same as the number of protons in its nucleus, so in this case, the atom has 6 protons. Choices A, C, and D are incorrect because they do not correspond to the correct number of protons for an atom with the given electron configuration and mass number. Therefore, option B, 6 protons, is the correct answer.
Which of the following is a property of amphiprotic substances?
- A. React with acids only
- B. React with bases only
- C. Can act as both acids and bases
- D. Are inert in chemical reactions
Correct Answer: C
Rationale: The correct answer is C: Can act as both acids and bases. Amphiprotic substances have the ability to donate a proton (act as an acid) or accept a proton (act as a base) depending on the reaction conditions. This dual nature allows them to participate in a wide range of chemical reactions, making them versatile and important in various chemical processes. Choices A and B are incorrect because amphiprotic substances are not limited to reacting with only acids or bases; they can interact with both. Choice D is incorrect because amphiprotic substances are not inert; they actively participate in chemical reactions by donating or accepting protons.
In which units is the speed of light in a vacuum measured?
- A. Meters per second
- B. Hertz
- C. Candela
- D. Newton
Correct Answer: A
Rationale: The speed of light in a vacuum is commonly measured in units of meters per second. This is because the speed of light is approximately 299,792,458 meters per second in a vacuum, as defined by the International System of Units (SI). The speed of light is a measure of distance covered by light in a given time, hence it is expressed in meters per second. Choices B, C, and D are incorrect. Hertz is a unit of frequency, Candela is a unit of luminous intensity, and Newton is a unit of force. None of these units are relevant for measuring the speed of light, making 'Meters per second' the correct unit of measurement for the speed of light.