CSET Subtest II – Certification Exam with 169 multiple-choice
questions with correct Answers and detailed rationales | Latest
2025/2026 Edition – Full Practice| full-length CSET Subtest II
(Science) practice exam!!!Updated.
The exam covers:
• Biology/Life Science (55 questions)
• Chemistry (50 questions)
• Physics (40 questions)
• Earth/Space Science (24 questions)
CSET Subtest II – Science Practice Exam
Biology/Life Science (Questions 1–55)
1. Which of the following best describes the role of NADH in cellular respiration?
a) It is a final electron acceptor in the ETC
b) It carries electrons from glycolysis and Krebs cycle to the ETC
c) It directly phosphorylates ADP to ATP
d) It splits glucose into pyruvate
Answer: b) It carries electrons from glycolysis and Krebs cycle to the ETC
Rationale: NADH is an electron carrier that donates electrons to the electron transport chain
(ETC), enabling ATP synthesis via oxidative phosphorylation.
2. A population of rabbits has fur color determined by a single gene with two alleles: B
(brown, dominant) and b (white, recessive). In a population of 500 rabbits, 20 are white.
Assuming Hardy–Weinberg equilibrium, how many are heterozygous?
a) 80
b) 160
, c) 320
d) 180
Answer: b) 160
*Rationale: q² = 20/500 = 0.04 → q = 0.2, p = 0.8. Heterozygotes = 2pq = 2(0.8)(0.2) = 0.32 ×
500 = 160.*
3. Which organelle is primarily responsible for protein synthesis?
a) Nucleus
b) Lysosome
c) Ribosome
d) Golgi apparatus
Answer: c) Ribosome
Rationale: Ribosomes translate mRNA into polypeptide chains. Nucleus stores DNA, Golgi
modifies/sorts proteins, lysosomes digest.
4. During which phase of meiosis does crossing over occur?
a) Prophase I
b) Metaphase I
c) Prophase II
d) Anaphase II
Answer: a) Prophase I
Rationale: Crossing over between homologous chromosomes occurs during prophase I,
increasing genetic diversity.
5. Which of the following is an example of a density-dependent limiting factor?
a) Volcanic eruption
b) Flood
c) Competition for food
d) Earthquake
Answer: c) Competition for food
Rationale: Density-dependent factors intensify as population density increases; competition,
predation, disease. Abiotic disasters are density-independent.
questions with correct Answers and detailed rationales | Latest
2025/2026 Edition – Full Practice| full-length CSET Subtest II
(Science) practice exam!!!Updated.
The exam covers:
• Biology/Life Science (55 questions)
• Chemistry (50 questions)
• Physics (40 questions)
• Earth/Space Science (24 questions)
CSET Subtest II – Science Practice Exam
Biology/Life Science (Questions 1–55)
1. Which of the following best describes the role of NADH in cellular respiration?
a) It is a final electron acceptor in the ETC
b) It carries electrons from glycolysis and Krebs cycle to the ETC
c) It directly phosphorylates ADP to ATP
d) It splits glucose into pyruvate
Answer: b) It carries electrons from glycolysis and Krebs cycle to the ETC
Rationale: NADH is an electron carrier that donates electrons to the electron transport chain
(ETC), enabling ATP synthesis via oxidative phosphorylation.
2. A population of rabbits has fur color determined by a single gene with two alleles: B
(brown, dominant) and b (white, recessive). In a population of 500 rabbits, 20 are white.
Assuming Hardy–Weinberg equilibrium, how many are heterozygous?
a) 80
b) 160
, c) 320
d) 180
Answer: b) 160
*Rationale: q² = 20/500 = 0.04 → q = 0.2, p = 0.8. Heterozygotes = 2pq = 2(0.8)(0.2) = 0.32 ×
500 = 160.*
3. Which organelle is primarily responsible for protein synthesis?
a) Nucleus
b) Lysosome
c) Ribosome
d) Golgi apparatus
Answer: c) Ribosome
Rationale: Ribosomes translate mRNA into polypeptide chains. Nucleus stores DNA, Golgi
modifies/sorts proteins, lysosomes digest.
4. During which phase of meiosis does crossing over occur?
a) Prophase I
b) Metaphase I
c) Prophase II
d) Anaphase II
Answer: a) Prophase I
Rationale: Crossing over between homologous chromosomes occurs during prophase I,
increasing genetic diversity.
5. Which of the following is an example of a density-dependent limiting factor?
a) Volcanic eruption
b) Flood
c) Competition for food
d) Earthquake
Answer: c) Competition for food
Rationale: Density-dependent factors intensify as population density increases; competition,
predation, disease. Abiotic disasters are density-independent.
