BIOS-251: EXAM 2 REVIEW NEWEST 2026 ACTUAL EXAM QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS) ALL ANSWERED {200 Q & A} ALREADY GRADED
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Question 1
Which organelle is responsible for oxidative phosphorylation and ATP production?
A) Ribosome
B) Mitochondria
C) Golgi apparatus
D) Lysosome
Answer: B) Mitochondria.
Rationale: Mitochondria are the "powerhouses of the cell" and are responsible for
producing ATP through oxidative phosphorylation, the primary energy source for the
cell .
Question 2
Which organelle synthesizes proteins?
A) Mitochondria
B) Golgi apparatus
C) Ribosomes
D) Lysosomes
Answer: C) Ribosomes.
Rationale: Ribosomes translate mRNA into proteins required for cellular functions. They
can be found free in the cytoplasm or attached to the rough endoplasmic reticulum .
,Question 3
Which organelle modifies, sorts, and packages proteins for secretion?
A) Rough ER
B) Smooth ER
C) Golgi apparatus
D) Lysosome
Answer: C) Golgi apparatus.
Rationale: The Golgi apparatus processes, sorts, and packages proteins into vesicles for
transport to their final destinations. It is often described as the "post office" of the cell .
Question 4
Which organelle detoxifies hydrogen peroxide?
A) Lysosome
B) Peroxisome
C) Mitochondria
D) Smooth ER
Answer: B) Peroxisome.
Rationale: Peroxisomes contain enzymes that break down fatty acids and neutralize
reactive oxygen species, including hydrogen peroxide, converting it to water and
oxygen .
Question 5
Which organelle stores calcium ions in muscle cells?
A) Mitochondria
B) Ribosomes
,C) Smooth endoplasmic reticulum
D) Rough endoplasmic reticulum
Answer: C) Smooth endoplasmic reticulum.
Rationale: Smooth ER has specialized functions depending on cell type. In skeletal
muscle cells, it is called the sarcoplasmic reticulum and stores calcium ions essential for
muscle contraction.
Question 6
Which macromolecule carries genetic information?
A) Carbohydrate
B) Lipid
C) Protein
D) Nucleic acid
Answer: D) Nucleic acid.
Rationale: DNA (deoxyribonucleic acid) stores hereditary information, while RNA plays
a role in protein synthesis. Both are nucleic acids .
Question 7
Proteins are composed of which monomers?
A) Monosaccharides
B) Fatty acids
C) Amino acids
D) Nucleotides
, Answer: C) Amino acids.
Rationale: Amino acids link via peptide bonds to form polypeptide chains, which fold
into functional proteins .
Question 8
Which carbohydrate forms plant cell walls?
A) Glycogen
B) Starch
C) Cellulose
D) Chitin
Answer: C) Cellulose.
Rationale: Cellulose provides structural rigidity to plant cell walls. In humans, glycogen
serves as the storage form of glucose .
Question 9
Which macromolecule stores long-term energy in animals?
A) Glycogen
B) Starch
C) Triglycerides (fats)
D) Cellulose
Answer: C) Triglycerides (fats).
Rationale: Triglycerides are stored in adipose tissue and provide long-term energy
reserves .
DETAILED ANSWERS (VERIFIED ANSWERS) ALL ANSWERED {200 Q & A} ALREADY GRADED
A+ | BRAND NEW! | 100% GUARANTEED PASS
Question 1
Which organelle is responsible for oxidative phosphorylation and ATP production?
A) Ribosome
B) Mitochondria
C) Golgi apparatus
D) Lysosome
Answer: B) Mitochondria.
Rationale: Mitochondria are the "powerhouses of the cell" and are responsible for
producing ATP through oxidative phosphorylation, the primary energy source for the
cell .
Question 2
Which organelle synthesizes proteins?
A) Mitochondria
B) Golgi apparatus
C) Ribosomes
D) Lysosomes
Answer: C) Ribosomes.
Rationale: Ribosomes translate mRNA into proteins required for cellular functions. They
can be found free in the cytoplasm or attached to the rough endoplasmic reticulum .
,Question 3
Which organelle modifies, sorts, and packages proteins for secretion?
A) Rough ER
B) Smooth ER
C) Golgi apparatus
D) Lysosome
Answer: C) Golgi apparatus.
Rationale: The Golgi apparatus processes, sorts, and packages proteins into vesicles for
transport to their final destinations. It is often described as the "post office" of the cell .
Question 4
Which organelle detoxifies hydrogen peroxide?
A) Lysosome
B) Peroxisome
C) Mitochondria
D) Smooth ER
Answer: B) Peroxisome.
Rationale: Peroxisomes contain enzymes that break down fatty acids and neutralize
reactive oxygen species, including hydrogen peroxide, converting it to water and
oxygen .
Question 5
Which organelle stores calcium ions in muscle cells?
A) Mitochondria
B) Ribosomes
,C) Smooth endoplasmic reticulum
D) Rough endoplasmic reticulum
Answer: C) Smooth endoplasmic reticulum.
Rationale: Smooth ER has specialized functions depending on cell type. In skeletal
muscle cells, it is called the sarcoplasmic reticulum and stores calcium ions essential for
muscle contraction.
Question 6
Which macromolecule carries genetic information?
A) Carbohydrate
B) Lipid
C) Protein
D) Nucleic acid
Answer: D) Nucleic acid.
Rationale: DNA (deoxyribonucleic acid) stores hereditary information, while RNA plays
a role in protein synthesis. Both are nucleic acids .
Question 7
Proteins are composed of which monomers?
A) Monosaccharides
B) Fatty acids
C) Amino acids
D) Nucleotides
, Answer: C) Amino acids.
Rationale: Amino acids link via peptide bonds to form polypeptide chains, which fold
into functional proteins .
Question 8
Which carbohydrate forms plant cell walls?
A) Glycogen
B) Starch
C) Cellulose
D) Chitin
Answer: C) Cellulose.
Rationale: Cellulose provides structural rigidity to plant cell walls. In humans, glycogen
serves as the storage form of glucose .
Question 9
Which macromolecule stores long-term energy in animals?
A) Glycogen
B) Starch
C) Triglycerides (fats)
D) Cellulose
Answer: C) Triglycerides (fats).
Rationale: Triglycerides are stored in adipose tissue and provide long-term energy
reserves .
