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Domain 1: General Science (GS) - 15 Questions
Q1: What is the primary function of mitochondria in a cell?
A. Protein synthesis
B. Cell division control
C. Energy production through cellular respiration [CORRECT]
D. Waste removal and storage
Correct Answer: C
Rationale: Mitochondria are the "powerhouses" of the cell, responsible for producing
ATP (adenosine triphosphate) through cellular respiration. The equation C₆H₁₂O₆ + 6O₂
→ 6CO₂ + 6H₂O + ATP represents this process. A is incorrect because protein synthesis
occurs at ribosomes. B is incorrect because cell division is controlled by the nucleus
and centrioles. D is incorrect because waste removal is handled by lysosomes and
vacuoles.
Q2: In DNA, which nitrogenous bases pair together?
A. Adenine with Cytosine, Guanine with Thymine
B. Adenine with Thymine, Guanine with Cytosine [CORRECT]
C. Adenine with Guanine, Cytosine with Thymine
D. All bases pair randomly
Correct Answer: B
,Rationale: DNA follows Chargaff's rules: Adenine (A) always pairs with Thymine (T) via
two hydrogen bonds, and Guanine (G) always pairs with Cytosine (C) via three hydrogen
bonds. This complementary base pairing maintains the double helix structure. A and C
are incorrect because they show impossible pairings that would disrupt the helix
geometry. D is incorrect because pairing is highly specific, not random.
Q3: What is the chemical equation for photosynthesis?
A. C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy
B. 6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂ [CORRECT]
C. 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ + ATP
D. C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ + energy
Correct Answer: B
Rationale: Photosynthesis converts carbon dioxide and water into glucose and oxygen
using light energy captured by chlorophyll. A is incorrect because it shows cellular
respiration (the reverse process). C is incorrect because ATP is not a product of
photosynthesis—glucose is. D is incorrect because it represents alcoholic fermentation.
Q4: Which human body system is responsible for transporting oxygen, nutrients, and
hormones throughout the body?
A. Respiratory system
B. Digestive system
C. Circulatory system [CORRECT]
D. Nervous system
Correct Answer: C
Rationale: The circulatory system consists of the heart (pump), arteries (carry
oxygenated blood away), veins (return deoxygenated blood), and capillaries (site of
exchange). A is incorrect because the respiratory system only exchanges gases (O₂ and
CO₂) at the lungs. B is incorrect because digestion breaks down food but doesn't
,transport substances systemically. D is incorrect because the nervous system transmits
electrical signals, not physical substances.
Q5: On the periodic table, where are metals generally located?
A. On the right side
B. In the middle only
C. On the left side and in the middle [CORRECT]
D. In the top rows only
Correct Answer: C
Rationale: Metals occupy the left side (Groups 1-2) and the central block (transition
metals, Groups 3-12). They typically lose electrons to form positive ions. A is incorrect
because nonmetals occupy the right side. B is incomplete as it excludes alkali and
alkaline earth metals. D is incorrect because metals appear throughout all periods.
Q6: What type of chemical bond involves the sharing of electron pairs between atoms?
A. Ionic bond
B. Covalent bond [CORRECT]
C. Hydrogen bond
D. Metallic bond
Correct Answer: B
Rationale: Covalent bonds form when atoms share electrons to achieve stable electron
configurations, as in H₂O or CO₂. A is incorrect because ionic bonds involve electron
transfer (e.g., NaCl). C is incorrect because hydrogen bonds are weak intermolecular
attractions, not true chemical bonds. D is incorrect because metallic bonds involve a
"sea" of delocalized electrons among metal cations.
Q7: According to Newton's Second Law of Motion, what is the relationship between
force, mass, and acceleration?
, A. F = m/a
B. F = m + a
C. F = m × a [CORRECT]
D. F = m - a
Correct Answer: C
Rationale: Newton's Second Law states that acceleration is directly proportional to net
force and inversely proportional to mass (a = F/m, rearranged to F = ma). A 10 kg mass
accelerating at 2 m/s² requires 20 N of force. A is incorrect because it inverts the
relationship. B and D are incorrect because force is multiplicative, not additive or
subtractive.
Q8: What is the mechanical advantage of a lever calculated by?
A. Load divided by effort
B. Distance from fulcrum to effort divided by distance from fulcrum to load [CORRECT]
C. Length of the lever divided by its weight
D. Effort multiplied by load
Correct Answer: B
Rationale: Mechanical Advantage (MA) = effort arm length / load arm length. If the
effort is 4 meters from the fulcrum and the load is 1 meter away, MA = 4, meaning 100
N of effort lifts 400 N of load. A describes the output but not the calculation method. C
and D are incorrect formulas with no physical meaning for lever mechanics.
Q9: Which layer of Earth's atmosphere contains the ozone layer?
A. Troposphere
B. Stratosphere [CORRECT]
C. Mesosphere
D. Thermosphere
Correct Answer: B