Nokea
What happens to the internal energy of a system when it performs work on its surroundings?
- A. It increases.
- B. It decreases.
- C. It remains the same.
- D. Insufficient information.
Correct Answer: B
Rationale: When a system performs work on its surroundings, it loses energy in the form of work done. This results in a decrease in the internal energy of the system. Work done by the system is considered as negative work, leading to a decrease in internal energy. Therefore, the correct answer is that the internal energy decreases when a system performs work on its surroundings. Choice A is incorrect as the internal energy decreases, not increases. Choice C is incorrect because the internal energy changes due to the work done. Choice D is incorrect because the information provided is sufficient to determine the change in internal energy.
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What is the protective sac surrounding the testes in the male reproductive system?
- A. Vas deferens
- B. Scrotum
- C. Epididymis
- D. Urethra
Correct Answer: B
Rationale: The scrotum is the correct answer, as it is the protective sac surrounding the testes in the male reproductive system. The scrotum's role is crucial in maintaining the optimal temperature for proper sperm production by regulating the distance of the testes from the body. The vas deferens is a duct responsible for transporting sperm from the testes to the urethra, not the protective sac surrounding the testes. The epididymis is a coiled tube where sperm mature and are stored before ejaculation, not the protective sac. The urethra is a tube that serves as a common passageway for both urine and semen to exit the body, not the protective sac surrounding the testes.
Why are isotopes of the same element chemically similar?
- A. They have the same number of protons.
- B. They have the same number of electrons.
- C. Their chemical properties are identical.
- D. They share the same electron configuration.
Correct Answer: A
Rationale: Isotopes of the same element are chemically similar because they have the same number of protons. The number of protons in an atom determines its atomic number, which is the defining characteristic of an element. Since chemical reactions primarily involve interactions between the electrons of atoms, having the same number of protons means the atoms have the same basic chemical properties. While isotopes may differ in the number of neutrons, it is the number of protons that dictates the element's identity and chemical behavior. Therefore, choice A is correct because the number of protons directly influences an element's chemical properties, making isotopes of the same element chemically similar despite potentially having different numbers of neutrons. Choices B, C, and D are incorrect because isotopes of the same element can have different numbers of electrons, their chemical properties are not identical due to potential differences in neutron numbers, and although they may have similarities in electron configurations, it is the number of protons that is the key factor determining chemical behavior.
A large geographic area characterized by similar climate, plants, and animals is called a:
- A. Population
- B. Community
- C. Biome
- D. Ecosystem
Correct Answer: C
Rationale: A) Population refers to a group of individuals of the same species living in a specific area.
B) Community refers to all the populations of different species living and interacting in a particular area.
C) Biome is a large geographic area characterized by similar climate, plants, and animals. Biomes are defined by factors such as temperature, precipitation, and vegetation types.
D) Ecosystem refers to a community of living organisms interacting with each other and their physical environment. An ecosystem can be part of a biome.
What is the formula to calculate acceleration?
- A. Acceleration = Mass/Force
- B. Acceleration = Force/Mass
- C. Acceleration = Time/Distance
- D. Acceleration = Time Change in Velocity
Correct Answer: D
Rationale: Acceleration is defined as the rate of change of velocity with respect to time. The correct formula to calculate acceleration is Acceleration = Time Change in Velocity. This formula specifically represents how much an object's velocity changes over a specified time period, providing a measure of the object's speed change rate. Choices A and B are incorrect as they do not represent the relationship between acceleration and time change in velocity. Choice C is incorrect as it involves time and distance, which are not directly related to acceleration.
Which of the following organelles is responsible for protein production in the cell?
- A. Ribosomes
- B. Golgi apparatus
- C. Mitochondria
- D. Lysosomes
Correct Answer: A
Rationale: The correct answer is A: Ribosomes. Ribosomes are the organelles responsible for protein synthesis in the cell. They can be found either freely floating in the cytoplasm or attached to the endoplasmic reticulum. The Golgi apparatus (Choice B) is involved in processing and packaging proteins, not protein production. Mitochondria (Choice C) are responsible for energy production, not protein synthesis. Lysosomes (Choice D) are involved in digestion and waste removal, not protein production.