BIOLOGY
No two people are genetically identical, except for identical twins. The main source of genetic variation among humans is:
A. New mutations occurring in the previous generation
B. Random changes in allele frequencies over time
C. Crossing over between homologous chromosomes in meiosis
D. Lifestyle and environmental factors affecting gene expression
Answer: C. Crossing over between homologous chromosomes in meiosis
What is the pH of a neutral solution at 25°C?
A. 0
B. 5
C. 7
D. 14
Answer: C. 7
Which type of plate boundary is most directly associated with deep ocean trenches and volcanic arcs?
A. Convergent boundary
B. Divergent Boundary
C. Transform Boundary
D. Passive boundary
Answer: A. Convergent boundary
What do you call the law that states that the induced current opposes the change in magnetic flux that produces it?
Answer: Lenz’s Law
A population of insects contains individuals with different levels of resistance to a pesticide. After repeated pesticide use, most surviving insects are resistant. Which mechanism of evolution best explains this change?
A. Genetic drift
B. Natural selection
C. Gene flow
D. Genetic mutation
Answer: B. Natural selection
Which type of reaction occurs when two or more substances combine to form one product?
A. Decomposition
B. Single displacement
C. Synthesis
D. Combustion
Answer: C. Synthesis
What is most likely to form when two continental plates collide?
A. mid-ocean ridge
B. A deep ocean trench
C. a large mountain range
D. A new ocean basin
Answer: C. a large mountain range
When water is heated in a pot, warmer water rises while cooler water sinks. What type of heat transfer is occurring?
Answer: Convection
What is the two-name system of naming organisms developed by Carl Linnaeus, in which each organism is given a genus name and a species name?
A. Taxonomic hierarchy
B. Binomial nomenclature
C. Dichotomous key
D. Phylogenetic classification
B. Binomial nomenclature
What is the correct name for Al₂O₃?
A. Aluminum oxide
B. Aluminum dioxide
C. Dialuminum oxide
D. Aluminum(III) oxygen
Answers: A. Aluminum oxide
Which observation provides the strongest evidence that seafloor spreading occurs at mid-ocean ridges?
A. Ocean trenches occur commonly near continental margins.
B. Transform faults occur along sections of the oceanic ridge.
C. Identical magnetic patterns occur symmetrically across the ridge.
D. Continental rocks are generally much older than oceanic rocks.
Answer: C. Identical magnetic patterns occur symmetrically across the ridge.
A 2 kg object moves in a circular path with a speed of 6 m/s and a radius of 3 m. What is the centripetal force acting on the object?
A. 12 N
B. 18 N
C. 24 N
D. 36 N
Answer: C. 24 N
What is the rhythmic, wave-like contraction of muscles that moves food through the digestive tract called?
Answer: peristalsis
Identify the type of chemical reaction represented by the equation:
2KClO₃ → 2KCl + 3O₂
Answer: Decomposition
What is the name given to a meteoroid that survives its passage through Earth’s atmosphere and reaches the ground?
Answer: Meteorite
A machine performs 2,400 J of work in 12 seconds. What is the power output of the machine?
Answer: C. 200 W
Which mechanism of evolution introduces new genetic variations by producing changes in an organism's DNA?
Answer: Mutation
A gas occupies 4.0 L at a pressure of 2.0 atm. If the temperature remains constant and the pressure is increased to 4.0 atm, what will be the new volume of the gas?
Answer: 2.0 L
Which major active fault system, approximately 1,200 kilometers long, bisects the Philippine archipelago, extending from northwestern Luzon to southeastern Mindanao?
A. West Valley Fault
B. Philippine Fault Zone
C. Philippine Sea Plate
D. Negros Trench
B. Philippine Fault Zone
What is the Universal Gravitational Constant?
Answer: G = 6.674 × 10⁻¹¹ N·m²/kg²
Answer: G = 6.674 × 10⁻¹¹ N·m²/kg²