, BIOL 101 MODULE 1 EXAM
Essential Biology I w/Lab
Portage Learning
100-Question Practice Examination
2026/2027 Edition
BIOL 101 Module 1 Exam | Essential Biology I w/Lab | Portage Learning | Q & A |
2026/2027 Edition (PDF)
1. A biologist measures a substance and finds that it has mass and occupies space.
Which conclusion is most appropriate?
A) The substance is matter.
B) The substance must be an element.
C) The substance must be organic.
D) The substance is necessarily alive.
Correct Answer: A) The substance is matter.
Rationale: Matter is anything that has mass and occupies space. An element is a specific type of matter, and organic
compounds are only one subset of matter. The observation alone gives no evidence that the substance is alive, so the
broad classification as matter is the only justified conclusion.
2. An atom has 8 protons, 8 neutrons, and 10 electrons. How should it bedescribed?
A) It is an anion with a -2 charge.
B) It is a neutral isotope.
C) It is a cation with a +2 charge.
D) It is an atom with atomic number 10.
Correct Answer: A) It is an anion with a -2 charge.
Rationale: Charge depends on the balance between positively charged protons and negatively charged electrons. Ten
electrons and eight protons yield two excess negative charges, producing a -2 anion. Atomic number equals the number of
protons, so the atomic number remains 8 regardless of neutron or electron count.
3. Two atoms share a pair of electrons. What type of bond is formed?
A) A covalent bond
B) An ionic bond
C) A hydrogen bond
D) A peptide bond
Correct Answer: A) A covalent bond
Rationale: A covalent bond forms when atoms share electron pairs. Ionic bonds arise from attraction between oppositely
charged ions after electron transfer, while hydrogen bonds are weaker intermolecular attractions. Peptide bonds are a
specialized covalent linkage between amino acids rather than a general description of electron sharing.
4. Sodium donates an electron to chlorine, producing Na+ and Cl-. What bestexplains the attraction between
these ions?
A) They share electrons equally.
B) They form a hydrogen bond.
C) Their neutrons become paired.
BIOL 101 Module 1 Practice Exam | 2026/2027 Edition Page 1
, D) Opposite electrical charges attract.
Correct Answer: D) Opposite electrical charges attract.
Rationale: Electron transfer creates oppositely charged ions. The electrostatic attraction between the positive sodium ion
and negative chloride ion is the basis of an ionic interaction. Equal sharing would describe nonpolar covalent bonding, and
neutrons do not participate in chemical bonding in this way.
5. Why can water molecules form hydrogen bonds with one another?
A) Water contains ionic bonds between H and O.
B) Water is nonpolar but highly reactive.
C) Water is polar, with partial charges on oxygen and hydrogen.
D) Water molecules share protons permanently.
Correct Answer: C) Water is polar, with partial charges on oxygen and hydrogen.
Rationale: Oxygen attracts shared electrons more strongly than hydrogen, creating partial negative charge near oxygen
and partial positive charge near hydrogens. These partial charges allow neighboring water molecules to form hydrogen
bonds. The O-H bonds within a water molecule are polar covalent, not ionic.
6. A drop of water beads on a waxed surface. Which property of water contributesmost directly to this behavior?
A) Cohesion among water molecules
B) Adhesion to the wax
C) Ionization of wax molecules
D) Hydrolysis of surface lipids
Correct Answer: A) Cohesion among water molecules
Rationale: Cohesion is the attraction of water molecules to one another through hydrogen bonding. When attraction
among water molecules exceeds attraction to a nonpolar wax surface, water tends to remain together as a bead.
Adhesion instead describes attraction between water and a different surface.
7. Water rises slightly in a narrow glass tube. Which paired properties explain this effect?
A) Adhesion to glass and cohesion between water molecules
B) Covalent bonding to glass and ionization
C) Hydrolysis and dehydration synthesis
D) Diffusion and active transport
Correct Answer: A) Adhesion to glass and cohesion between water molecules
Rationale: Capillary action results from adhesion of water to a surface together with cohesion among water molecules.
Adhesion draws water along the glass, while cohesion helps pull additional water molecules upward. The effect does not
require active transport or chemical reactions such as hydrolysis.
8. A solution changes from pH 7 to pH 5. How has the hydrogen ion concentrationchanged?
A) It has increased 100-fold.
B) It has increased 2-fold.
C) It has decreased 100-fold.
D) It has remained unchanged.
Correct Answer: A) It has increased 100-fold.
Rationale: The pH scale is logarithmic. A decrease of two pH units corresponds to a 10 x 10, or 100-fold, increase in
hydrogen ion concentration. Lower pH means greater hydrogen ion concentration, so the solution has become more
acidic rather than less acidic.
9. Which substance would most effectively resist a sudden change in pH when asmall amount of acid is
added?
BIOL 101 Module 1 Practice Exam | 2026/2027 Edition Page 2
Essential Biology I w/Lab
Portage Learning
100-Question Practice Examination
2026/2027 Edition
BIOL 101 Module 1 Exam | Essential Biology I w/Lab | Portage Learning | Q & A |
2026/2027 Edition (PDF)
1. A biologist measures a substance and finds that it has mass and occupies space.
Which conclusion is most appropriate?
A) The substance is matter.
B) The substance must be an element.
C) The substance must be organic.
D) The substance is necessarily alive.
Correct Answer: A) The substance is matter.
Rationale: Matter is anything that has mass and occupies space. An element is a specific type of matter, and organic
compounds are only one subset of matter. The observation alone gives no evidence that the substance is alive, so the
broad classification as matter is the only justified conclusion.
2. An atom has 8 protons, 8 neutrons, and 10 electrons. How should it bedescribed?
A) It is an anion with a -2 charge.
B) It is a neutral isotope.
C) It is a cation with a +2 charge.
D) It is an atom with atomic number 10.
Correct Answer: A) It is an anion with a -2 charge.
Rationale: Charge depends on the balance between positively charged protons and negatively charged electrons. Ten
electrons and eight protons yield two excess negative charges, producing a -2 anion. Atomic number equals the number of
protons, so the atomic number remains 8 regardless of neutron or electron count.
3. Two atoms share a pair of electrons. What type of bond is formed?
A) A covalent bond
B) An ionic bond
C) A hydrogen bond
D) A peptide bond
Correct Answer: A) A covalent bond
Rationale: A covalent bond forms when atoms share electron pairs. Ionic bonds arise from attraction between oppositely
charged ions after electron transfer, while hydrogen bonds are weaker intermolecular attractions. Peptide bonds are a
specialized covalent linkage between amino acids rather than a general description of electron sharing.
4. Sodium donates an electron to chlorine, producing Na+ and Cl-. What bestexplains the attraction between
these ions?
A) They share electrons equally.
B) They form a hydrogen bond.
C) Their neutrons become paired.
BIOL 101 Module 1 Practice Exam | 2026/2027 Edition Page 1
, D) Opposite electrical charges attract.
Correct Answer: D) Opposite electrical charges attract.
Rationale: Electron transfer creates oppositely charged ions. The electrostatic attraction between the positive sodium ion
and negative chloride ion is the basis of an ionic interaction. Equal sharing would describe nonpolar covalent bonding, and
neutrons do not participate in chemical bonding in this way.
5. Why can water molecules form hydrogen bonds with one another?
A) Water contains ionic bonds between H and O.
B) Water is nonpolar but highly reactive.
C) Water is polar, with partial charges on oxygen and hydrogen.
D) Water molecules share protons permanently.
Correct Answer: C) Water is polar, with partial charges on oxygen and hydrogen.
Rationale: Oxygen attracts shared electrons more strongly than hydrogen, creating partial negative charge near oxygen
and partial positive charge near hydrogens. These partial charges allow neighboring water molecules to form hydrogen
bonds. The O-H bonds within a water molecule are polar covalent, not ionic.
6. A drop of water beads on a waxed surface. Which property of water contributesmost directly to this behavior?
A) Cohesion among water molecules
B) Adhesion to the wax
C) Ionization of wax molecules
D) Hydrolysis of surface lipids
Correct Answer: A) Cohesion among water molecules
Rationale: Cohesion is the attraction of water molecules to one another through hydrogen bonding. When attraction
among water molecules exceeds attraction to a nonpolar wax surface, water tends to remain together as a bead.
Adhesion instead describes attraction between water and a different surface.
7. Water rises slightly in a narrow glass tube. Which paired properties explain this effect?
A) Adhesion to glass and cohesion between water molecules
B) Covalent bonding to glass and ionization
C) Hydrolysis and dehydration synthesis
D) Diffusion and active transport
Correct Answer: A) Adhesion to glass and cohesion between water molecules
Rationale: Capillary action results from adhesion of water to a surface together with cohesion among water molecules.
Adhesion draws water along the glass, while cohesion helps pull additional water molecules upward. The effect does not
require active transport or chemical reactions such as hydrolysis.
8. A solution changes from pH 7 to pH 5. How has the hydrogen ion concentrationchanged?
A) It has increased 100-fold.
B) It has increased 2-fold.
C) It has decreased 100-fold.
D) It has remained unchanged.
Correct Answer: A) It has increased 100-fold.
Rationale: The pH scale is logarithmic. A decrease of two pH units corresponds to a 10 x 10, or 100-fold, increase in
hydrogen ion concentration. Lower pH means greater hydrogen ion concentration, so the solution has become more
acidic rather than less acidic.
9. Which substance would most effectively resist a sudden change in pH when asmall amount of acid is
added?
BIOL 101 Module 1 Practice Exam | 2026/2027 Edition Page 2
