PENN FOSTER INTRODUCTION TO BIOLOGY
PRACTICE ASSESSMENT 2026 FULL
QUESTIONS AND ANSWERS GRADED A PLUS
COMPLETE REVISION GUIDE 300 ITEMS
◉ Scientific Theory.
Answer: The foundation of scientific knowledge; a well-
substantiated explanation of some aspect of the natural world, based
on a body of facts and verified through repeated testing and
observation
◉ Variables.
Answer: Factors in an experiment that can be changed
◉ Controlled Variables.
Answer: Factors in an experiment that do not change
◉ Independent Variables (Manipulated).
Answer: Factors in an experiment which are intentionally changed
◉ Dependent Variables (Responding).
Answer: The result of the changed variables in an experiment
,◉ Control Group.
Answer: A group that continues under existing conditions
◉ Experimental Group.
Answer: A group exposed to something being tested in the
experiment
◉ Null Hypothesis.
Answer: The first proposed explanation for a phenomenon to be
tested
◉ Alternative Hypothesis.
Answer: Provides other explanations should the proposed
explanation for a phenomenon be rejected by the experiment results
◉ Matter.
Answer: Composed of elements
◉ Elements.
Answer: Composed of atoms; a substance which can be broken down
into simpler substances via chemical reaction; 118 defined, 94
naturally occurring on earth.
, ◉ Atom.
Answer: The smallest component of an element which retains all
chemical properties of that element.
◉ Isotope.
Answer: Atoms of the same element that have different numbers of
neutrons, but the same number of protons and electrons
◉ Valence Electrons.
Answer: Electrons on the outermost energy level of an atom
◉ Ionic Bond.
Answer: Formed when one or more electrons are transferred from
one atom to another; formed between ions of opposite charges
◉ Covalent Bond.
Answer: A chemical bond that involves sharing a pair of electrons
between atoms in a molecule
◉ Polar Covalent Bond.
Answer: A covalent bond in which electrons are not shared equally;
Example: Hydrogen bonding to Oxygen in H2O
PRACTICE ASSESSMENT 2026 FULL
QUESTIONS AND ANSWERS GRADED A PLUS
COMPLETE REVISION GUIDE 300 ITEMS
◉ Scientific Theory.
Answer: The foundation of scientific knowledge; a well-
substantiated explanation of some aspect of the natural world, based
on a body of facts and verified through repeated testing and
observation
◉ Variables.
Answer: Factors in an experiment that can be changed
◉ Controlled Variables.
Answer: Factors in an experiment that do not change
◉ Independent Variables (Manipulated).
Answer: Factors in an experiment which are intentionally changed
◉ Dependent Variables (Responding).
Answer: The result of the changed variables in an experiment
,◉ Control Group.
Answer: A group that continues under existing conditions
◉ Experimental Group.
Answer: A group exposed to something being tested in the
experiment
◉ Null Hypothesis.
Answer: The first proposed explanation for a phenomenon to be
tested
◉ Alternative Hypothesis.
Answer: Provides other explanations should the proposed
explanation for a phenomenon be rejected by the experiment results
◉ Matter.
Answer: Composed of elements
◉ Elements.
Answer: Composed of atoms; a substance which can be broken down
into simpler substances via chemical reaction; 118 defined, 94
naturally occurring on earth.
, ◉ Atom.
Answer: The smallest component of an element which retains all
chemical properties of that element.
◉ Isotope.
Answer: Atoms of the same element that have different numbers of
neutrons, but the same number of protons and electrons
◉ Valence Electrons.
Answer: Electrons on the outermost energy level of an atom
◉ Ionic Bond.
Answer: Formed when one or more electrons are transferred from
one atom to another; formed between ions of opposite charges
◉ Covalent Bond.
Answer: A chemical bond that involves sharing a pair of electrons
between atoms in a molecule
◉ Polar Covalent Bond.
Answer: A covalent bond in which electrons are not shared equally;
Example: Hydrogen bonding to Oxygen in H2O
