DCCC BIO 150 Practice Test 1 Questions
and Answers Plus Rationales 100%
Correct (A+ Graded) || LATEST UPDATE
2026
Q1. The atomic number of an element represents:
A. Number of neutrons
B. Number of protons
C. Atomic mass
D. Electrons only
Correct Answer: B
Rationale: Atomic number equals the number of protons in the nucleus.
Q2. Isotopes differ in:
A. Protons
B. Electrons
C. Neutrons
D. Atomic charge
Correct Answer: C
Rationale: Isotopes have the same protons but different neutrons.
Q3. A covalent bond involves:
A. Transfer of electrons
B. Sharing of electrons
C. Proton exchange
D. Hydrogen ion release
Correct Answer: B
Rationale: Covalent bonds form when atoms share electrons.
,Q4. Hydrogen bonds are important in:
A. Ionic compounds only
B. Water cohesion
C. DNA stability
D. Both B and C
Correct Answer: D
Rationale: Hydrogen bonds stabilize water molecules and DNA base pairing.
Q5. Water’s high specific heat is due to:
A. Ionic bonds
B. Hydrogen bonding
C. Nonpolar structure
D. Hydrophobic effect
Correct Answer: B
Q6. A pH of 3 is:
A. Basic
B. Neutral
C. Acidic
D. Alkaline
Correct Answer: C
Q7. Buffers function to:
A. Raise pH only
B. Lower pH only
C. Resist changes in pH
D. Destroy acids
Correct Answer: C
Q8. The four major biological macromolecules are:
, A. Sugars, salts, fats, DNA
B. Carbohydrates, lipids, proteins, nucleic acids
C. Proteins, minerals, vitamins, DNA
D. RNA, ATP, enzymes, glucose
Correct Answer: B
Q9. Monomers of proteins are:
A. Fatty acids
B. Nucleotides
C. Amino acids
D. Monosaccharides
Correct Answer: C
Q10. A dehydration reaction:
A. Uses water to break bonds
B. Removes water to build polymers
C. Produces ATP
D. Breaks ionic bonds only
Correct Answer: B
🍞 SECTION 2: Macromolecules
Q11. Glycogen is:
A. Plant storage
B. Animal carbohydrate storage
C. Lipid
D. Enzyme
Correct Answer: B
and Answers Plus Rationales 100%
Correct (A+ Graded) || LATEST UPDATE
2026
Q1. The atomic number of an element represents:
A. Number of neutrons
B. Number of protons
C. Atomic mass
D. Electrons only
Correct Answer: B
Rationale: Atomic number equals the number of protons in the nucleus.
Q2. Isotopes differ in:
A. Protons
B. Electrons
C. Neutrons
D. Atomic charge
Correct Answer: C
Rationale: Isotopes have the same protons but different neutrons.
Q3. A covalent bond involves:
A. Transfer of electrons
B. Sharing of electrons
C. Proton exchange
D. Hydrogen ion release
Correct Answer: B
Rationale: Covalent bonds form when atoms share electrons.
,Q4. Hydrogen bonds are important in:
A. Ionic compounds only
B. Water cohesion
C. DNA stability
D. Both B and C
Correct Answer: D
Rationale: Hydrogen bonds stabilize water molecules and DNA base pairing.
Q5. Water’s high specific heat is due to:
A. Ionic bonds
B. Hydrogen bonding
C. Nonpolar structure
D. Hydrophobic effect
Correct Answer: B
Q6. A pH of 3 is:
A. Basic
B. Neutral
C. Acidic
D. Alkaline
Correct Answer: C
Q7. Buffers function to:
A. Raise pH only
B. Lower pH only
C. Resist changes in pH
D. Destroy acids
Correct Answer: C
Q8. The four major biological macromolecules are:
, A. Sugars, salts, fats, DNA
B. Carbohydrates, lipids, proteins, nucleic acids
C. Proteins, minerals, vitamins, DNA
D. RNA, ATP, enzymes, glucose
Correct Answer: B
Q9. Monomers of proteins are:
A. Fatty acids
B. Nucleotides
C. Amino acids
D. Monosaccharides
Correct Answer: C
Q10. A dehydration reaction:
A. Uses water to break bonds
B. Removes water to build polymers
C. Produces ATP
D. Breaks ionic bonds only
Correct Answer: B
🍞 SECTION 2: Macromolecules
Q11. Glycogen is:
A. Plant storage
B. Animal carbohydrate storage
C. Lipid
D. Enzyme
Correct Answer: B
