Nokea
What property of a wave determines the loudness of sound when heard by the human ear?
- A. Frequency
- B. Amplitude
- C. Wavelength
- D. Velocity
Correct Answer: B
Rationale: The amplitude of a wave determines the loudness of sound when heard by the human ear. The greater the amplitude of a sound wave, the louder the sound will be perceived. Frequency (Choice A) refers to the number of wave cycles in a given time period. Wavelength (Choice C) is the distance between two corresponding points on a wave. Velocity (Choice D) is the speed at which the wave travels and does not directly affect the loudness of sound perceived by the human ear.
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Which of the following statements is true regarding a supersaturated solution?
- A. It is unstable and tends to crystallize
- B. It contains more solute than it could dissolve
- C. It has a higher concentration than a saturated solution
- D. It is rarely encountered in everyday solutions
Correct Answer: A
Rationale: A supersaturated solution is unstable and tends to crystallize because it contains more solute than it could dissolve at a given temperature. This excess solute is in a metastable state and can precipitate out if disturbed, leading to the formation of crystals. Option B is incorrect because a supersaturated solution does contain more solute than it could normally dissolve, but it becomes unstable due to this excess solute. Option C is incorrect because while a supersaturated solution does have a higher concentration than a saturated solution, the defining characteristic related to its instability is the excess solute. Option D is incorrect as supersaturated solutions can be encountered in various everyday scenarios, such as certain sugar solutions used in cooking or rock candy production.
What characteristic unites all organisms in the kingdom Animalia?
- A. Multicellularity and heterotrophy
- B. Unicellular nature
- C. Photosynthesis
- D. Cell walls made of chitin
Correct Answer: A
Rationale: A) Multicellularity and heterotrophy: This is the correct answer because all organisms in the kingdom Animalia are multicellular (composed of multiple cells) and exhibit heterotrophy (obtain nutrients by consuming other organisms).
B) Unicellular nature: This is incorrect because organisms in the kingdom Animalia are multicellular, not unicellular.
C) Photosynthesis: This is incorrect because organisms in the kingdom Animalia do not perform photosynthesis; they are heterotrophs that obtain nutrients by consuming other organisms.
D) Cell walls made of chitin: This is incorrect because organisms in the kingdom Animalia do not have cell walls made of chitin. Chitin is a structural polysaccharide found in the cell walls of fungi, not animals.
Which organelle is responsible for carrying out photosynthesis in plant cells?
- A. Golgi apparatus
- B. Mitochondria
- C. Chloroplasts
- D. Lysosomes
Correct Answer: C
Rationale: A) Golgi apparatus: The Golgi apparatus is responsible for modifying, sorting, and packaging proteins for secretion or for use within the cell. It is not involved in photosynthesis.
B) Mitochondria: Mitochondria are known as the powerhouse of the cell and are responsible for generating energy in the form of ATP through cellular respiration. They are not involved in photosynthesis.
C) Chloroplasts: Chloroplasts are the organelles responsible for carrying out photosynthesis in plant cells. They contain chlorophyll, a pigment that captures light energy and converts it into chemical energy in the form of glucose.
D) Lysosomes: Lysosomes are membrane-bound organelles that contain digestive enzymes to break down waste materials and cellular debris. They are not involved in photosynthesis.
Therefore, the correct answer is C) Chloroplasts, as they are specifically responsible for carrying out photosynthesis in plant
Which type of lens focuses parallel light rays to a single point?
- A. Concave lens
- B. Convex lens
- C. Cylindrical lens
- D. Plano lens
Correct Answer: B
Rationale: A convex lens focuses parallel light rays to a single point by causing them to converge. This lens is thicker in the center than at the edges, which helps in converging the light rays. Convex lenses are commonly used for tasks like magnification and focusing due to their ability to bring distant light rays to a single focal point. Choice A, the concave lens, diverges light rays rather than converging them, making it incorrect. Choice C, the cylindrical lens, is designed to focus light along one axis rather than converging parallel light rays to a single point. Choice D, the plano lens, has no curvatures to bend or focus light rays, so it does not converge parallel light rays.
Which element is a critical component of DNA and RNA, essential for storing and transmitting genetic information?
- A. Oxygen
- B. Carbon
- C. Nitrogen
- D. Hydrogen
Correct Answer: B
Rationale: Carbon is the correct answer as it is a critical element in DNA and RNA, forming the backbone of these molecules. Its ability to form diverse bonds allows for efficient storage and transmission of genetic information. Oxygen, nitrogen, and hydrogen are also present in DNA and RNA but do not serve as the primary backbone element for these molecules. Oxygen is involved in the structure but not as the backbone element. Nitrogen is present in the bases of nucleotides, and hydrogen bonds help stabilize the structure.