ESTUDYR
C190 Introduction To Biology (WGU) Module 3
Genetics
1. Hydrogen bonds attract _______ or parts of molecules to each other.
A. Ions
B. Atoms
C. Electrons
D. Molecules
Correct Answer: D
Rationale: Hydrogen bonds form between partial charges on polar molecules, attracting
one molecule to another.
2. A ______________ bond forms between the oxygen of one molecule and the
hydrogen of another molecule.
A. Covalent bond
B. Ionic bond
C. Hydrogen bond
D. Metallic bond
Correct Answer: C
Rationale: Hydrogen bonds occur between regions of molecules with partial charges,
such as O–H in water.
3. As a result of keeping more electrons, oxygen develops a partial charge. What
charge?
A. Partial positive
B. Neutral
C. Full negative
D. Partial negative
Correct Answer: D
Rationale: Oxygen is more electronegative, so it holds electrons longer → partial
negative (δ−).
4. In a polar covalent bond, which atom keeps electrons longer in an O–H bond?
A. Hydrogen
B. Carbon
C. Nitrogen
D. Oxygen
, ESTUDYR
Correct Answer: D
Rationale: Oxygen has high electronegativity → stronger pull on shared electrons.
5. The most strongly electronegative elements in biological systems are:
A. Hydrogen & carbon
B. Phosphorus & sulfur
C. Oxygen & nitrogen
D. Sodium & chlorine
Correct Answer: C
Rationale: O and N most strongly attract electrons → essential in polar molecules.
6. Atoms like oxygen have ______ electronegativity.
A. Low
B. Medium
C. None
D. High
Correct Answer: D
Rationale: High electronegativity atoms pull electrons strongly.
7. Electronegativity is defined as:
A. Number of neutrons in an atom
B. The tendency of an atom to hold shared electrons close to its nucleus
C. Movement of electrons between shells
D. The ability to gain protons
Correct Answer: B
Rationale: This describes how strongly an atom attracts shared electrons.
8. A water molecule is formed by what type of bond between O and H?
A. Ionic
B. Metallic
C. Covalent
D. Hydrogen
Correct Answer: C
Rationale: Electrons are shared between oxygen and hydrogen.
9. Electrons are shared in which type of bond?
A. Ionic
B. Metallic
C190 Introduction To Biology (WGU) Module 3
Genetics
1. Hydrogen bonds attract _______ or parts of molecules to each other.
A. Ions
B. Atoms
C. Electrons
D. Molecules
Correct Answer: D
Rationale: Hydrogen bonds form between partial charges on polar molecules, attracting
one molecule to another.
2. A ______________ bond forms between the oxygen of one molecule and the
hydrogen of another molecule.
A. Covalent bond
B. Ionic bond
C. Hydrogen bond
D. Metallic bond
Correct Answer: C
Rationale: Hydrogen bonds occur between regions of molecules with partial charges,
such as O–H in water.
3. As a result of keeping more electrons, oxygen develops a partial charge. What
charge?
A. Partial positive
B. Neutral
C. Full negative
D. Partial negative
Correct Answer: D
Rationale: Oxygen is more electronegative, so it holds electrons longer → partial
negative (δ−).
4. In a polar covalent bond, which atom keeps electrons longer in an O–H bond?
A. Hydrogen
B. Carbon
C. Nitrogen
D. Oxygen
, ESTUDYR
Correct Answer: D
Rationale: Oxygen has high electronegativity → stronger pull on shared electrons.
5. The most strongly electronegative elements in biological systems are:
A. Hydrogen & carbon
B. Phosphorus & sulfur
C. Oxygen & nitrogen
D. Sodium & chlorine
Correct Answer: C
Rationale: O and N most strongly attract electrons → essential in polar molecules.
6. Atoms like oxygen have ______ electronegativity.
A. Low
B. Medium
C. None
D. High
Correct Answer: D
Rationale: High electronegativity atoms pull electrons strongly.
7. Electronegativity is defined as:
A. Number of neutrons in an atom
B. The tendency of an atom to hold shared electrons close to its nucleus
C. Movement of electrons between shells
D. The ability to gain protons
Correct Answer: B
Rationale: This describes how strongly an atom attracts shared electrons.
8. A water molecule is formed by what type of bond between O and H?
A. Ionic
B. Metallic
C. Covalent
D. Hydrogen
Correct Answer: C
Rationale: Electrons are shared between oxygen and hydrogen.
9. Electrons are shared in which type of bond?
A. Ionic
B. Metallic
