PENN FOSTER INTRODUCTION TO BIOLOGY
EXAM ACTUAL PAPER 2026 QUESTIONS WITH
SOLUTIONS GRADED A PLUS COMPLETE
REVIEW SET 300 ITEMS
◉ A modification that makes organisms more suited to their
environment is called a/an:
Answer: Adaptation
◉ During a scientific experiment, the control group is:
Answer: Identical to the experimental group in all areas except the
variable being tested
◉ When an atom has 2 or more electron shells, the outer shell will
be most stable if it contains 8 electrons. This concept is called the:
Answer: Octet rule
◉ When 2 oxygen atoms join together, a __ is formed.
Answer: Molecule
◉ The __ bond is a type of atomic bonds in which atoms share
electrons to produce a completed outer shell.
,Answer: Covalent
◉ The polarity of water molecules causes them to be attracted to
one another by a __ bond.
Answer: Hydrogen
◉ As the number of hydrogen ions in a solution increases, the pH of
the solution:
Answer: Decreases
◉ During winter only the upper surface of a lake freezes, which
allows for life to persist below the surface. Which of water's unique
properties is responsible for this phenomenon?
Answer: Lower density as ice
◉ The most abundant element by weight in the human body is
Answer: Oxygen
◉ The polysaccharide structural carbohydrate most commonly used
by living things is:
Answer: Cellulose
, ◉ Which one of the following functional groups is associated with
fatty acids?
Answer: Carboxyl
◉ The hard body parts of insects and crabs are composed of a
polysaccharide called:
Answer: Chitin
◉ Cell membranes are composed mainly of which type of lipids?
Answer: Phospholipids
◉ ___ proteins are made of polypeptide chains folded into rounded
compact shapes.
Answer: Globular
◉ When joined by a dehydration reaction, the covalent bond
between the carboxyl groups of two amino acids is called a ____ bond.
Answer: Peptide
◉ The sugar in RNA is:
Answer: Ribose
◉ Within cells, the synthesis of proteins occurs in the:
EXAM ACTUAL PAPER 2026 QUESTIONS WITH
SOLUTIONS GRADED A PLUS COMPLETE
REVIEW SET 300 ITEMS
◉ A modification that makes organisms more suited to their
environment is called a/an:
Answer: Adaptation
◉ During a scientific experiment, the control group is:
Answer: Identical to the experimental group in all areas except the
variable being tested
◉ When an atom has 2 or more electron shells, the outer shell will
be most stable if it contains 8 electrons. This concept is called the:
Answer: Octet rule
◉ When 2 oxygen atoms join together, a __ is formed.
Answer: Molecule
◉ The __ bond is a type of atomic bonds in which atoms share
electrons to produce a completed outer shell.
,Answer: Covalent
◉ The polarity of water molecules causes them to be attracted to
one another by a __ bond.
Answer: Hydrogen
◉ As the number of hydrogen ions in a solution increases, the pH of
the solution:
Answer: Decreases
◉ During winter only the upper surface of a lake freezes, which
allows for life to persist below the surface. Which of water's unique
properties is responsible for this phenomenon?
Answer: Lower density as ice
◉ The most abundant element by weight in the human body is
Answer: Oxygen
◉ The polysaccharide structural carbohydrate most commonly used
by living things is:
Answer: Cellulose
, ◉ Which one of the following functional groups is associated with
fatty acids?
Answer: Carboxyl
◉ The hard body parts of insects and crabs are composed of a
polysaccharide called:
Answer: Chitin
◉ Cell membranes are composed mainly of which type of lipids?
Answer: Phospholipids
◉ ___ proteins are made of polypeptide chains folded into rounded
compact shapes.
Answer: Globular
◉ When joined by a dehydration reaction, the covalent bond
between the carboxyl groups of two amino acids is called a ____ bond.
Answer: Peptide
◉ The sugar in RNA is:
Answer: Ribose
◉ Within cells, the synthesis of proteins occurs in the:
