Here’s a revision test for Campbell Biology, Chapter 1-25- The Chemical Context of Life, with answers
and rationales provided.
Revision Test: The Chemical Context of Life
Multiple-Choice Questions (MCQs)
1. What is the smallest unit of matter that retains the properties of an element?
A) Molecule
B) Atom
C) Proton
D) Compound
Answer: B) Atom
Rationale: Atoms are the fundamental units of elements, maintaining their chemical properties.
Molecules and compounds consist of atoms bonded together, and protons are just one subatomic
particle.
2. Which four elements make up approximately 96% of living matter?
A) Carbon, Oxygen, Nitrogen, Hydrogen
B) Calcium, Phosphorus, Potassium, Sulfur
C) Iron, Zinc, Magnesium, Sodium
D) Carbon, Helium, Oxygen, Calcium
Answer: A) Carbon, Oxygen, Nitrogen, Hydrogen
Rationale: These four elements are essential for biological molecules like proteins, lipids, carbohydrates,
and nucleic acids.
3. The atomic number of an element refers to the number of:
A) Neutrons
B) Protons
C) Electrons
D) Protons and neutrons
Answer: B) Protons
Rationale: The atomic number is unique to each element and equals the number of protons in the
nucleus. It also determines the element’s identity.
4. Which type of bond results from the sharing of electron pairs between atoms?
,A) Ionic bond
B) Hydrogen bond
C) Covalent bond
D) Van der Waals interaction
Answer: C) Covalent bond
Rationale: Covalent bonds involve the sharing of electron pairs between atoms, forming strong
connections that contribute to molecular structure.
5. In a water molecule, why does oxygen have a partial negative charge?
A) Oxygen donates electrons to hydrogen
B) Oxygen is more electronegative than hydrogen
C) Hydrogen has a greater mass than oxygen
D) Oxygen loses electrons
Answer: B) Oxygen is more electronegative than hydrogen
Rationale: Oxygen attracts electrons more strongly than hydrogen, resulting in a partial negative charge
on oxygen and a partial positive charge on hydrogen, leading to polarity.
6. An ionic bond forms when:
A) Two atoms share electrons equally
B) One atom transfers electrons to another
C) Two atoms share protons
D) Hydrogen atoms bond weakly to another atom
Answer: B) One atom transfers electrons to another
Rationale: Ionic bonds occur when an atom donates or gains electrons, leading to positively and
negatively charged ions that attract each other.
7. Which property of water allows it to resist changes in temperature?
A) Cohesion
B) Adhesion
C) High specific heat
D) Solvent ability
Answer: C) High specific heat
Rationale: Water has a high specific heat, meaning it can absorb and store a large amount of heat
before changing temperature. This helps regulate temperature in living organisms and ecosystems.
8. Which of the following is a trace element essential for life?
, A) Hydrogen
B) Nitrogen
C) Iron
D) Carbon
Answer: C) Iron
Rationale: Trace elements like iron are required in small amounts but are vital for functions such as
oxygen transport in blood (hemoglobin).
9. What type of weak chemical bond helps reinforce the shape of large molecules like proteins and
holds the two strands of DNA together?
A) Ionic bonds
B) Covalent bonds
C) Hydrogen bonds
D) Van der Waals interactions
Answer: C) Hydrogen bonds
Rationale: Hydrogen bonds are weak individually but collectively provide stability in biological structures
like DNA and proteins.
10. Which of the following best explains why water is a good solvent?
A) It is a large molecule
B) It has high cohesion
C) It is polar
D) It has a high specific heat
Answer: C) It is polar
Rationale: Water’s polarity allows it to interact with and dissolve other polar molecules and ions,
making it an excellent solvent for biological reactions.
Would you like additional question formats (e.g., short answers, true/false), or do you need more
focus on specific topics within the chapter? 😊
Here’s a revision test covering Chapters 1 to 7 of Campbell Biology, with answers and rationales
included.
Comprehensive Revision Test (Chapters 1-7)
Chapter 1: Introduction - Themes in the Study of Life
1. Which of the following best describes emergent properties?
and rationales provided.
Revision Test: The Chemical Context of Life
Multiple-Choice Questions (MCQs)
1. What is the smallest unit of matter that retains the properties of an element?
A) Molecule
B) Atom
C) Proton
D) Compound
Answer: B) Atom
Rationale: Atoms are the fundamental units of elements, maintaining their chemical properties.
Molecules and compounds consist of atoms bonded together, and protons are just one subatomic
particle.
2. Which four elements make up approximately 96% of living matter?
A) Carbon, Oxygen, Nitrogen, Hydrogen
B) Calcium, Phosphorus, Potassium, Sulfur
C) Iron, Zinc, Magnesium, Sodium
D) Carbon, Helium, Oxygen, Calcium
Answer: A) Carbon, Oxygen, Nitrogen, Hydrogen
Rationale: These four elements are essential for biological molecules like proteins, lipids, carbohydrates,
and nucleic acids.
3. The atomic number of an element refers to the number of:
A) Neutrons
B) Protons
C) Electrons
D) Protons and neutrons
Answer: B) Protons
Rationale: The atomic number is unique to each element and equals the number of protons in the
nucleus. It also determines the element’s identity.
4. Which type of bond results from the sharing of electron pairs between atoms?
,A) Ionic bond
B) Hydrogen bond
C) Covalent bond
D) Van der Waals interaction
Answer: C) Covalent bond
Rationale: Covalent bonds involve the sharing of electron pairs between atoms, forming strong
connections that contribute to molecular structure.
5. In a water molecule, why does oxygen have a partial negative charge?
A) Oxygen donates electrons to hydrogen
B) Oxygen is more electronegative than hydrogen
C) Hydrogen has a greater mass than oxygen
D) Oxygen loses electrons
Answer: B) Oxygen is more electronegative than hydrogen
Rationale: Oxygen attracts electrons more strongly than hydrogen, resulting in a partial negative charge
on oxygen and a partial positive charge on hydrogen, leading to polarity.
6. An ionic bond forms when:
A) Two atoms share electrons equally
B) One atom transfers electrons to another
C) Two atoms share protons
D) Hydrogen atoms bond weakly to another atom
Answer: B) One atom transfers electrons to another
Rationale: Ionic bonds occur when an atom donates or gains electrons, leading to positively and
negatively charged ions that attract each other.
7. Which property of water allows it to resist changes in temperature?
A) Cohesion
B) Adhesion
C) High specific heat
D) Solvent ability
Answer: C) High specific heat
Rationale: Water has a high specific heat, meaning it can absorb and store a large amount of heat
before changing temperature. This helps regulate temperature in living organisms and ecosystems.
8. Which of the following is a trace element essential for life?
, A) Hydrogen
B) Nitrogen
C) Iron
D) Carbon
Answer: C) Iron
Rationale: Trace elements like iron are required in small amounts but are vital for functions such as
oxygen transport in blood (hemoglobin).
9. What type of weak chemical bond helps reinforce the shape of large molecules like proteins and
holds the two strands of DNA together?
A) Ionic bonds
B) Covalent bonds
C) Hydrogen bonds
D) Van der Waals interactions
Answer: C) Hydrogen bonds
Rationale: Hydrogen bonds are weak individually but collectively provide stability in biological structures
like DNA and proteins.
10. Which of the following best explains why water is a good solvent?
A) It is a large molecule
B) It has high cohesion
C) It is polar
D) It has a high specific heat
Answer: C) It is polar
Rationale: Water’s polarity allows it to interact with and dissolve other polar molecules and ions,
making it an excellent solvent for biological reactions.
Would you like additional question formats (e.g., short answers, true/false), or do you need more
focus on specific topics within the chapter? 😊
Here’s a revision test covering Chapters 1 to 7 of Campbell Biology, with answers and rationales
included.
Comprehensive Revision Test (Chapters 1-7)
Chapter 1: Introduction - Themes in the Study of Life
1. Which of the following best describes emergent properties?
