1|Page
NLN NEX SCIENCE ACTUAL EXAM PREP 2026
ALL QUESTIONS AND CORRECT DETAILED
ANSWERS WITH RATIONALES ALREADY A
GRADED WITH EXPERT FEEDBACK |NEW AND
REVISED
FOCUS:Science – Biology, Chemistry, and Physics/Physical Science
Section 1: Biology
1. Which organelle is responsible for producing ATP through cellular
respiration?
A) Nucleus
B) Mitochondria
C) Golgi apparatus
D) Ribosome
Rationale: Mitochondria are known as the "powerhouses" of the cell
because they produce ATP through aerobic cellular respiration. The
nucleus contains genetic material, the Golgi apparatus modifies and
packages proteins, and ribosomes synthesize proteins.
2. Which structure in the cell is responsible for protein synthesis?
A) Nucleus
B) Lysosome
C) Ribosome
D) Peroxisome
Rationale: Ribosomes are the sites of protein synthesis, translating
messenger RNA into polypeptide chains. The nucleus houses DNA,
,2|Page
lysosomes are involved in cellular digestion, and peroxisomes are
involved in lipid metabolism and detoxification.
3. The process by which cells divide to produce two identical daughter
cells is called:
A) Meiosis
B) Mitosis
C) Binary fission
D) Cytokinesis
Rationale: Mitosis is the process of cell division that produces two
genetically identical daughter cells, essential for growth and repair.
Meiosis produces gametes with half the chromosome number. Binary
fission is prokaryotic division. Cytokinesis is the division of cytoplasm.
4. Which of the following is the correct sequence of phases in the cell
cycle?
A) G₁, G₂, S, M
B) G₁, M, S, G₂
C) G₁, S, G₂, M
D) S, G₁, G₂, M
Rationale: The cell cycle follows the sequence G₁ (growth), S (DNA
replication), G₂ (preparation for division), and M (mitosis). This order
ensures that DNA replication occurs before cell division.
5. In meiosis, how many daughter cells are produced, and what is their
chromosome number?
A) Two diploid cells
B) Four haploid cells
C) Four diploid cells
,3|Page
D) Two haploid cells
Rationale: Meiosis produces four haploid daughter cells, each with half
the chromosome number of the parent cell. This is essential for sexual
reproduction. Mitosis produces two diploid daughter cells.
6. Which of the following is an example of a polysaccharide?
A) Glucose
B) Fructose
C) Sucrose
D) Starch
Rationale: Starch is a polysaccharide composed of many glucose units
linked together. Glucose and fructose are monosaccharides, and sucrose
is a disaccharide.
7. The building blocks of proteins are:
A) Monosaccharides
B) Nucleotides
C) Amino acids
D) Fatty acids
Rationale: Amino acids are the monomers that link together to form
proteins through peptide bonds. Monosaccharides form carbohydrates,
nucleotides form nucleic acids, and fatty acids are components of lipids.
8. Which of the following is NOT a function of the plasma membrane?
A) Selective permeability
B) Cell signaling
C) Protection and structural support
D) Protein synthesis
, 4|Page
Rationale: The plasma membrane provides selective permeability, cell
signaling, and protection/support. Protein synthesis occurs at
ribosomes, not the plasma membrane.
9. The movement of water across a semipermeable membrane from an
area of lower solute concentration to higher solute concentration is
called:
A) Diffusion
B) Osmosis
C) Active transport
D) Facilitated diffusion
Rationale: Osmosis is the specific movement of water across a
selectively permeable membrane from low solute concentration to high
solute concentration. Diffusion refers to the movement of solutes, and
active transport requires energy.
10. Which organelle contains digestive enzymes and is involved in
cellular waste disposal?
A) Ribosome
B) Golgi apparatus
C) Lysosome
D) Endoplasmic reticulum
Rationale: Lysosomes contain digestive enzymes that break down waste
materials and cellular debris. Ribosomes synthesize proteins, the Golgi
apparatus processes proteins, and the endoplasmic reticulum is involved
in protein and lipid synthesis.
11. DNA replication occurs during which phase of the cell cycle?
A) G₁ phase
NLN NEX SCIENCE ACTUAL EXAM PREP 2026
ALL QUESTIONS AND CORRECT DETAILED
ANSWERS WITH RATIONALES ALREADY A
GRADED WITH EXPERT FEEDBACK |NEW AND
REVISED
FOCUS:Science – Biology, Chemistry, and Physics/Physical Science
Section 1: Biology
1. Which organelle is responsible for producing ATP through cellular
respiration?
A) Nucleus
B) Mitochondria
C) Golgi apparatus
D) Ribosome
Rationale: Mitochondria are known as the "powerhouses" of the cell
because they produce ATP through aerobic cellular respiration. The
nucleus contains genetic material, the Golgi apparatus modifies and
packages proteins, and ribosomes synthesize proteins.
2. Which structure in the cell is responsible for protein synthesis?
A) Nucleus
B) Lysosome
C) Ribosome
D) Peroxisome
Rationale: Ribosomes are the sites of protein synthesis, translating
messenger RNA into polypeptide chains. The nucleus houses DNA,
,2|Page
lysosomes are involved in cellular digestion, and peroxisomes are
involved in lipid metabolism and detoxification.
3. The process by which cells divide to produce two identical daughter
cells is called:
A) Meiosis
B) Mitosis
C) Binary fission
D) Cytokinesis
Rationale: Mitosis is the process of cell division that produces two
genetically identical daughter cells, essential for growth and repair.
Meiosis produces gametes with half the chromosome number. Binary
fission is prokaryotic division. Cytokinesis is the division of cytoplasm.
4. Which of the following is the correct sequence of phases in the cell
cycle?
A) G₁, G₂, S, M
B) G₁, M, S, G₂
C) G₁, S, G₂, M
D) S, G₁, G₂, M
Rationale: The cell cycle follows the sequence G₁ (growth), S (DNA
replication), G₂ (preparation for division), and M (mitosis). This order
ensures that DNA replication occurs before cell division.
5. In meiosis, how many daughter cells are produced, and what is their
chromosome number?
A) Two diploid cells
B) Four haploid cells
C) Four diploid cells
,3|Page
D) Two haploid cells
Rationale: Meiosis produces four haploid daughter cells, each with half
the chromosome number of the parent cell. This is essential for sexual
reproduction. Mitosis produces two diploid daughter cells.
6. Which of the following is an example of a polysaccharide?
A) Glucose
B) Fructose
C) Sucrose
D) Starch
Rationale: Starch is a polysaccharide composed of many glucose units
linked together. Glucose and fructose are monosaccharides, and sucrose
is a disaccharide.
7. The building blocks of proteins are:
A) Monosaccharides
B) Nucleotides
C) Amino acids
D) Fatty acids
Rationale: Amino acids are the monomers that link together to form
proteins through peptide bonds. Monosaccharides form carbohydrates,
nucleotides form nucleic acids, and fatty acids are components of lipids.
8. Which of the following is NOT a function of the plasma membrane?
A) Selective permeability
B) Cell signaling
C) Protection and structural support
D) Protein synthesis
, 4|Page
Rationale: The plasma membrane provides selective permeability, cell
signaling, and protection/support. Protein synthesis occurs at
ribosomes, not the plasma membrane.
9. The movement of water across a semipermeable membrane from an
area of lower solute concentration to higher solute concentration is
called:
A) Diffusion
B) Osmosis
C) Active transport
D) Facilitated diffusion
Rationale: Osmosis is the specific movement of water across a
selectively permeable membrane from low solute concentration to high
solute concentration. Diffusion refers to the movement of solutes, and
active transport requires energy.
10. Which organelle contains digestive enzymes and is involved in
cellular waste disposal?
A) Ribosome
B) Golgi apparatus
C) Lysosome
D) Endoplasmic reticulum
Rationale: Lysosomes contain digestive enzymes that break down waste
materials and cellular debris. Ribosomes synthesize proteins, the Golgi
apparatus processes proteins, and the endoplasmic reticulum is involved
in protein and lipid synthesis.
11. DNA replication occurs during which phase of the cell cycle?
A) G₁ phase
