LATEST PRAXIS GENERAL
SCIENCE (5435) OFFERED BY ETS |
Q&A WITH RATIONALES
1. Which of the following best defines a scientific
hypothesis?
A) A proven fact based on extensive evidence
B) A testable prediction that guides experimentation
C) A conclusion drawn from a single observation
D) A tentative explanation that cannot be tested
Correct answer: B
Rationale: A scientific hypothesis is a testable
prediction or proposed explanation that can be
investigated through experimentation and
observation.
2. A student measures the mass of an object as 250
grams and its volume as 50 cubic centimeters. What
is the density of the object?
A) 0.2 g/cm³
,B) 5 g/cm³
C) 50 g/cm³
D) 12500 g/cm³
Correct answer: B
Rationale: Density is calculated by dividing mass by
volume (D = m/V). Therefore, 250 g / 50 cm³ = 5
g/cm³.
3. Which organelle is responsible for the synthesis of
ATP through cellular respiration?
A) Nucleus
B) Ribosome
C) Mitochondrion
D) Golgi apparatus
Correct answer: C
Rationale: Mitochondria are known as the
"powerhouses" of the cell because they are the
primary site of aerobic cellular respiration, where
glucose is broken down to produce ATP.
,4. In a food web, which organisms occupy the first
trophic level?
A) Primary consumers
B) Secondary consumers
C) Producers
D) Decomposers
Correct answer: C
Rationale: Producers (such as plants and algae) form
the base of the food web at the first trophic level.
They convert light energy into chemical energy
through photosynthesis.
5. A solution has a pH of 3. This solution would be
classified as:
A) A strong base
B) A weak base
C) A neutral substance
D) A strong acid
Correct answer: D
Rationale: The pH scale ranges from 0 to 14. A pH
below 7 indicates an acidic solution; the lower the
, pH, the stronger the acid. A pH of 3 is strongly
acidic.
6. Which of the following forces is responsible for
keeping planets in orbit around the Sun?
A) Electromagnetic force
B) Gravitational force
C) Nuclear force
D) Frictional force
Correct answer: B
Rationale: Gravity is the attractive force between
objects with mass. The Sun's gravitational pull
provides the centripetal force that keeps planets in
their elliptical orbits.
7. A rock sample is found to have distinct layers. This
rock is most likely:
A) Igneous
B) Metamorphic
C) Sedimentary
D) Volcanic
SCIENCE (5435) OFFERED BY ETS |
Q&A WITH RATIONALES
1. Which of the following best defines a scientific
hypothesis?
A) A proven fact based on extensive evidence
B) A testable prediction that guides experimentation
C) A conclusion drawn from a single observation
D) A tentative explanation that cannot be tested
Correct answer: B
Rationale: A scientific hypothesis is a testable
prediction or proposed explanation that can be
investigated through experimentation and
observation.
2. A student measures the mass of an object as 250
grams and its volume as 50 cubic centimeters. What
is the density of the object?
A) 0.2 g/cm³
,B) 5 g/cm³
C) 50 g/cm³
D) 12500 g/cm³
Correct answer: B
Rationale: Density is calculated by dividing mass by
volume (D = m/V). Therefore, 250 g / 50 cm³ = 5
g/cm³.
3. Which organelle is responsible for the synthesis of
ATP through cellular respiration?
A) Nucleus
B) Ribosome
C) Mitochondrion
D) Golgi apparatus
Correct answer: C
Rationale: Mitochondria are known as the
"powerhouses" of the cell because they are the
primary site of aerobic cellular respiration, where
glucose is broken down to produce ATP.
,4. In a food web, which organisms occupy the first
trophic level?
A) Primary consumers
B) Secondary consumers
C) Producers
D) Decomposers
Correct answer: C
Rationale: Producers (such as plants and algae) form
the base of the food web at the first trophic level.
They convert light energy into chemical energy
through photosynthesis.
5. A solution has a pH of 3. This solution would be
classified as:
A) A strong base
B) A weak base
C) A neutral substance
D) A strong acid
Correct answer: D
Rationale: The pH scale ranges from 0 to 14. A pH
below 7 indicates an acidic solution; the lower the
, pH, the stronger the acid. A pH of 3 is strongly
acidic.
6. Which of the following forces is responsible for
keeping planets in orbit around the Sun?
A) Electromagnetic force
B) Gravitational force
C) Nuclear force
D) Frictional force
Correct answer: B
Rationale: Gravity is the attractive force between
objects with mass. The Sun's gravitational pull
provides the centripetal force that keeps planets in
their elliptical orbits.
7. A rock sample is found to have distinct layers. This
rock is most likely:
A) Igneous
B) Metamorphic
C) Sedimentary
D) Volcanic
