Principles of Biology I Final TWU
Exam Actual Questions and Answers
2026
The reactivity of an atom arises from -
correct answer ✅the existence of unpaired electrons in the
valence shell.
How many electron pairs are shared between carbon atoms in a
molecule that has the formula C2H4? -
correct answer ✅2
Water molecules can form hydrogen bonds with -
correct answer ✅compounds that have polar covalent bonds
To act as an effective coolant in a car's radiator, a substance has to
have the capacity to absorb a great deal of heat. You have a
reference book with tables listing the physical properties of many
liquids. In choosing a coolant for your car, which table would you
check first? -
correct answer ✅specific heat
The partial negative charge in a molecule of water occurs because -
correct answer ✅the electrons shared between the oxygen and
hydrogen atoms spend more time around the oxygen atom nucleus
than around the hydrogen atom nucleus
,Principles of Biology I Final TWU
Exam Actual Questions and Answers
2026
Humans can digest starch but not cellulose because -
correct answer ✅a humans have enzymes that can hydrolyze the
α-glycosidic linkages of starch but not the β-glycosidic linkages of
cellulose
Why are hydrocarbons insoluble in water? -
correct answer ✅The majority of their bonds are nonpolar
covalent carbon-to-hydrogen linkages.
Which two functional groups are always found in amino acids? -
correct answer ✅carboxyl and amino groups
Which of the following best summarizes the relationship between
dehydration reactions and hydrolysis? -
correct answer ✅Dehydration reactions assemble polymers;
hydrolysis reactions break polymers apart.
Which atom matches this electron configurations 1s2 2s2 2p5? -
correct answer ✅Fluorine
, Principles of Biology I Final TWU
Exam Actual Questions and Answers
2026
How many valence electrons are present in Fluorine? -
correct answer ✅7
Can the atomic mass of an element vary? -
correct answer ✅Yes. Adding or losing neutrons will change the
atomic mass without forming a different element.
Compared to a hydrocarbon chain where all the carbon atoms are
linked by single bonds, a hydrocarbon chain with the same number
of carbon atoms but with one or more double bonds will -
correct answer ✅be more constrained in structure
What is the major structural difference between starch and
glycogen? -
correct answer ✅the amount of branching that occurs in the
molecule
You disrupt all hydrogen bonds in a protein. What level of structure
will be preserved? -
correct answer ✅primary structure
Exam Actual Questions and Answers
2026
The reactivity of an atom arises from -
correct answer ✅the existence of unpaired electrons in the
valence shell.
How many electron pairs are shared between carbon atoms in a
molecule that has the formula C2H4? -
correct answer ✅2
Water molecules can form hydrogen bonds with -
correct answer ✅compounds that have polar covalent bonds
To act as an effective coolant in a car's radiator, a substance has to
have the capacity to absorb a great deal of heat. You have a
reference book with tables listing the physical properties of many
liquids. In choosing a coolant for your car, which table would you
check first? -
correct answer ✅specific heat
The partial negative charge in a molecule of water occurs because -
correct answer ✅the electrons shared between the oxygen and
hydrogen atoms spend more time around the oxygen atom nucleus
than around the hydrogen atom nucleus
,Principles of Biology I Final TWU
Exam Actual Questions and Answers
2026
Humans can digest starch but not cellulose because -
correct answer ✅a humans have enzymes that can hydrolyze the
α-glycosidic linkages of starch but not the β-glycosidic linkages of
cellulose
Why are hydrocarbons insoluble in water? -
correct answer ✅The majority of their bonds are nonpolar
covalent carbon-to-hydrogen linkages.
Which two functional groups are always found in amino acids? -
correct answer ✅carboxyl and amino groups
Which of the following best summarizes the relationship between
dehydration reactions and hydrolysis? -
correct answer ✅Dehydration reactions assemble polymers;
hydrolysis reactions break polymers apart.
Which atom matches this electron configurations 1s2 2s2 2p5? -
correct answer ✅Fluorine
, Principles of Biology I Final TWU
Exam Actual Questions and Answers
2026
How many valence electrons are present in Fluorine? -
correct answer ✅7
Can the atomic mass of an element vary? -
correct answer ✅Yes. Adding or losing neutrons will change the
atomic mass without forming a different element.
Compared to a hydrocarbon chain where all the carbon atoms are
linked by single bonds, a hydrocarbon chain with the same number
of carbon atoms but with one or more double bonds will -
correct answer ✅be more constrained in structure
What is the major structural difference between starch and
glycogen? -
correct answer ✅the amount of branching that occurs in the
molecule
You disrupt all hydrogen bonds in a protein. What level of structure
will be preserved? -
correct answer ✅primary structure
