,BIOD 101 Module 1 Essential Biology I | Portage
Learning | Questions & Verified Answers | 2026
Edition
1. Which of the following best describes the scientific method as a process?
A) A rigid sequence of steps that must always be followed in the same order
B) A flexible approach involving observation, hypothesis formation, experimentation, and conclusion
C) A method used exclusively in laboratory settings with controlled variables
D) A technique for proving absolute scientific truths beyond any doubt
Correct Answer: A flexible approach involving observation, hypothesis formation, experimentation, and
conclusion
Rationale: The scientific method is a dynamic, flexible process that includes making observations,
forming hypotheses, conducting experiments, and drawing conclusions. It is not rigidly fixed in order and
does not claim to prove absolute truths, but rather supports or refutes hypotheses based on evidence.
This approach is foundational to all biological inquiry.
2. What is matter, and in which states can it exist?
A) Matter is any substance that has mass and takes up space; it can exist as solid, liquid, gas, or plasma
B) Matter is any substance that has weight; it can exist as solid or liquid only
C) Matter is any substance that can be seen; it can exist as solid, liquid, or gas
D) Matter is any substance that contains carbon; it can exist as solid or gas only
Correct Answer: Matter is any substance that has mass and takes up space; it can exist as solid, liquid,
gas, or plasma
Rationale: Matter is defined as anything that occupies space (has volume) and possesses mass. It can
exist in four primary states: solid, liquid, gas, and plasma. The plasma state is less commonly discussed in
introductory biology but is a valid state of matter.
,3. Which six elements make up approximately 98% of an organism's mass?
A) Carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus
B) Carbon, hydrogen, oxygen, nitrogen, calcium, and potassium
C) Carbon, hydrogen, oxygen, nitrogen, sodium, and chlorine
D) Carbon, hydrogen, oxygen, nitrogen, magnesium, and iron
Correct Answer: Carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus
Rationale: These six elements—carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus (CHONSP)—
compose roughly 98% of the mass of living organisms. They are considered essential elements required
for human life and are the primary building blocks of biological molecules.
4. How do trace elements differ from essential elements in biological systems?
A) Trace elements are not required for human life, while essential elements are
B) Trace elements are required only in small quantities, whereas essential elements are needed in larger
amounts
C) Trace elements are found only in plants, while essential elements are found only in animals
D) Trace elements are synthetic, while essential elements are naturally occurring
Correct Answer: Trace elements are required only in small quantities, whereas essential elements are
needed in larger amounts
Rationale: Essential elements such as carbon, hydrogen, oxygen, and nitrogen are needed in relatively
large amounts for life processes. Trace elements, including iron and iodine, are required only in minute
quantities but remain vital for proper physiological function.
5. What distinguishes an element from a compound?
A) An element cannot be broken down into simpler substances, while a compound consists of different
types of atoms bonded together
B) An element is always a gas, while a compound is always a solid
C) An element contains only one type of atom, while a compound contains only one type of molecule
, D) An element is synthetic, while a compound is naturally occurring
Correct Answer: An element cannot be broken down into simpler substances, while a compound
consists of different types of atoms bonded together
Rationale: Elements are pure substances that cannot be broken down chemically into simpler
substances. Compounds are molecules composed of two or more different types of atoms chemically
bonded together. There are 92 naturally occurring elements.
6. What type of bond forms when one atom donates electrons to another atom?
A) Covalent bond
B) Hydrogen bond
C) Ionic bond
D) Polar covalent bond
Correct Answer: Ionic bond
Rationale: An ionic bond forms when one atom transfers electrons to another, creating oppositely
charged ions that attract each other. The atom that loses electrons becomes a positively charged cation,
while the atom that gains electrons becomes a negatively charged anion.
7. Which statement accurately describes a covalent bond?
A) Electrons are transferred from one atom to another, creating charged ions
B) Electrons are shared equally or unequally between two atoms to complete their valence shells
C) Electrons are exchanged between atoms through weak electrostatic interactions
D) Electrons are completely removed from both atoms, leaving them without valence electrons
Correct Answer: Electrons are shared equally or unequally between two atoms to complete their
valence shells
Learning | Questions & Verified Answers | 2026
Edition
1. Which of the following best describes the scientific method as a process?
A) A rigid sequence of steps that must always be followed in the same order
B) A flexible approach involving observation, hypothesis formation, experimentation, and conclusion
C) A method used exclusively in laboratory settings with controlled variables
D) A technique for proving absolute scientific truths beyond any doubt
Correct Answer: A flexible approach involving observation, hypothesis formation, experimentation, and
conclusion
Rationale: The scientific method is a dynamic, flexible process that includes making observations,
forming hypotheses, conducting experiments, and drawing conclusions. It is not rigidly fixed in order and
does not claim to prove absolute truths, but rather supports or refutes hypotheses based on evidence.
This approach is foundational to all biological inquiry.
2. What is matter, and in which states can it exist?
A) Matter is any substance that has mass and takes up space; it can exist as solid, liquid, gas, or plasma
B) Matter is any substance that has weight; it can exist as solid or liquid only
C) Matter is any substance that can be seen; it can exist as solid, liquid, or gas
D) Matter is any substance that contains carbon; it can exist as solid or gas only
Correct Answer: Matter is any substance that has mass and takes up space; it can exist as solid, liquid,
gas, or plasma
Rationale: Matter is defined as anything that occupies space (has volume) and possesses mass. It can
exist in four primary states: solid, liquid, gas, and plasma. The plasma state is less commonly discussed in
introductory biology but is a valid state of matter.
,3. Which six elements make up approximately 98% of an organism's mass?
A) Carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus
B) Carbon, hydrogen, oxygen, nitrogen, calcium, and potassium
C) Carbon, hydrogen, oxygen, nitrogen, sodium, and chlorine
D) Carbon, hydrogen, oxygen, nitrogen, magnesium, and iron
Correct Answer: Carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus
Rationale: These six elements—carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus (CHONSP)—
compose roughly 98% of the mass of living organisms. They are considered essential elements required
for human life and are the primary building blocks of biological molecules.
4. How do trace elements differ from essential elements in biological systems?
A) Trace elements are not required for human life, while essential elements are
B) Trace elements are required only in small quantities, whereas essential elements are needed in larger
amounts
C) Trace elements are found only in plants, while essential elements are found only in animals
D) Trace elements are synthetic, while essential elements are naturally occurring
Correct Answer: Trace elements are required only in small quantities, whereas essential elements are
needed in larger amounts
Rationale: Essential elements such as carbon, hydrogen, oxygen, and nitrogen are needed in relatively
large amounts for life processes. Trace elements, including iron and iodine, are required only in minute
quantities but remain vital for proper physiological function.
5. What distinguishes an element from a compound?
A) An element cannot be broken down into simpler substances, while a compound consists of different
types of atoms bonded together
B) An element is always a gas, while a compound is always a solid
C) An element contains only one type of atom, while a compound contains only one type of molecule
, D) An element is synthetic, while a compound is naturally occurring
Correct Answer: An element cannot be broken down into simpler substances, while a compound
consists of different types of atoms bonded together
Rationale: Elements are pure substances that cannot be broken down chemically into simpler
substances. Compounds are molecules composed of two or more different types of atoms chemically
bonded together. There are 92 naturally occurring elements.
6. What type of bond forms when one atom donates electrons to another atom?
A) Covalent bond
B) Hydrogen bond
C) Ionic bond
D) Polar covalent bond
Correct Answer: Ionic bond
Rationale: An ionic bond forms when one atom transfers electrons to another, creating oppositely
charged ions that attract each other. The atom that loses electrons becomes a positively charged cation,
while the atom that gains electrons becomes a negatively charged anion.
7. Which statement accurately describes a covalent bond?
A) Electrons are transferred from one atom to another, creating charged ions
B) Electrons are shared equally or unequally between two atoms to complete their valence shells
C) Electrons are exchanged between atoms through weak electrostatic interactions
D) Electrons are completely removed from both atoms, leaving them without valence electrons
Correct Answer: Electrons are shared equally or unequally between two atoms to complete their
valence shells
