WGU C190 INTRO TO BIOLOGY OA EXAM 4
2026 FULL SOLVED QUESTIONS ANSWERS
CELL STRUCTURE AND FUNCTION REVIEW
SHEET
◉ Codons-.
Answer: A sequence of three nucleotides in an mRNA molecule that
specifies which amino acid should be added to a growing
polypeptide chain.
◉ Commensalism-.
Answer: A symbiotic relationship in which one species benefits and
the other does not, but also is not harmed.
◉ Competition-.
Answer: A type of interspecific interaction where both species are
harmed.
◉ complementary base pairing-.
Answer: Describes the hydrogen bonding that occurs between
specific nucleotides on opposing strands of DNA or RNA. In DNA,
adenine is paired with thymine, and guanine is paired with cytosine.
,When RNA is made from DNA, adenine is paired with uracil, and
guanine is paired with cytosine.
◉ Consumers-.
Answer: An organism that must eat or absorb complex food
molecules derived from the bodies of other organisms. Consumers
get their energy and nutrients from such food molecules. Humans
and other animals are consumers, as are fungi and most bacteria.
◉ covalent bonds-.
Answer: Covalent bonds represent the sharing of the electrons
(negatively charged subatomic particles between atoms). The
number of covalent bonds that can form is dictated by the number of
unpaired electrons in the outer valence shell of the atom.
◉ Cytoplasm-.
Answer: The substance that fills the inside contents of a cell between
the plasma membrane and the nucleus. Contains a semifluid
medium, composed mainly of water, and organelles (organelles are
present only if it is a eukaryotic cell).
◉ Cytoskeleton-.
Answer: A eukaryotic cell structure formed by a series of protein
filaments. The cytoskeleton is a scaffold for the cell structure and a
,framework for many cellular activities, including movement and cell
division.
◉ Decomposer-.
Answer: Bacteria and fungi that colonize dead material and absorb
food molecules from it.
◉ deoxyribonucleic acid (DNA)-.
Answer: A nucleic acid polymer that contains the genetic
instructions for all living organisms. DNA is composed of two
strands of nucleotides that are intertwined in a double helix.
◉ Detritivores-.
Answer: Animals that feed on dead organic matter. Some detritivores
specialize on eating dead animals (e.g., vultures) and others feed on
dead plant material (e.g., earthworms).
◉ Disaccharide-.
Answer: A carbohydrate made of two monosaccharides linked
together by a covalent bond. Two common disaccharides are sucrose
and lactose. glucose + fructose = Sucrose (table sugar) glucose +
galactose = Lactose (milk sugar)
◉ DNA: deoxyribonucleic acid-.
, Answer: The nucleic acid that contains genetic instructions for
making RNA and, ultimately, proteins in all living organisms. DNA is
composed of two strands of nucleotides, which are intertwined in a
double helix.
◉ Ecology-.
Answer: The branch of biology that deals with the relations of
organisms to one another and to their physical surroundings.
◉ ecosystem diversity-.
Answer: The variety of distinct ecosystem types (habitats) within a
region. In some places a wide array of habitats can form a diverse
patchwork of life.
◉ electron transport chain-.
Answer: The last stage of aerobic cellular respiration where the
NADH and FADH2 made in other steps deposit their electrons. As
electrons move down the chain, energy is released and used to move
protons across the mitochondrial membrane to form ATP. At the end
of this process, oxygen acts as the final electron acceptor to form
water.
◉ Electronegativity-.
Answer: The tendancy of an atom to hold shared electrons more
close to its nucleus. Atoms like oxygen have a high electronegativity.
2026 FULL SOLVED QUESTIONS ANSWERS
CELL STRUCTURE AND FUNCTION REVIEW
SHEET
◉ Codons-.
Answer: A sequence of three nucleotides in an mRNA molecule that
specifies which amino acid should be added to a growing
polypeptide chain.
◉ Commensalism-.
Answer: A symbiotic relationship in which one species benefits and
the other does not, but also is not harmed.
◉ Competition-.
Answer: A type of interspecific interaction where both species are
harmed.
◉ complementary base pairing-.
Answer: Describes the hydrogen bonding that occurs between
specific nucleotides on opposing strands of DNA or RNA. In DNA,
adenine is paired with thymine, and guanine is paired with cytosine.
,When RNA is made from DNA, adenine is paired with uracil, and
guanine is paired with cytosine.
◉ Consumers-.
Answer: An organism that must eat or absorb complex food
molecules derived from the bodies of other organisms. Consumers
get their energy and nutrients from such food molecules. Humans
and other animals are consumers, as are fungi and most bacteria.
◉ covalent bonds-.
Answer: Covalent bonds represent the sharing of the electrons
(negatively charged subatomic particles between atoms). The
number of covalent bonds that can form is dictated by the number of
unpaired electrons in the outer valence shell of the atom.
◉ Cytoplasm-.
Answer: The substance that fills the inside contents of a cell between
the plasma membrane and the nucleus. Contains a semifluid
medium, composed mainly of water, and organelles (organelles are
present only if it is a eukaryotic cell).
◉ Cytoskeleton-.
Answer: A eukaryotic cell structure formed by a series of protein
filaments. The cytoskeleton is a scaffold for the cell structure and a
,framework for many cellular activities, including movement and cell
division.
◉ Decomposer-.
Answer: Bacteria and fungi that colonize dead material and absorb
food molecules from it.
◉ deoxyribonucleic acid (DNA)-.
Answer: A nucleic acid polymer that contains the genetic
instructions for all living organisms. DNA is composed of two
strands of nucleotides that are intertwined in a double helix.
◉ Detritivores-.
Answer: Animals that feed on dead organic matter. Some detritivores
specialize on eating dead animals (e.g., vultures) and others feed on
dead plant material (e.g., earthworms).
◉ Disaccharide-.
Answer: A carbohydrate made of two monosaccharides linked
together by a covalent bond. Two common disaccharides are sucrose
and lactose. glucose + fructose = Sucrose (table sugar) glucose +
galactose = Lactose (milk sugar)
◉ DNA: deoxyribonucleic acid-.
, Answer: The nucleic acid that contains genetic instructions for
making RNA and, ultimately, proteins in all living organisms. DNA is
composed of two strands of nucleotides, which are intertwined in a
double helix.
◉ Ecology-.
Answer: The branch of biology that deals with the relations of
organisms to one another and to their physical surroundings.
◉ ecosystem diversity-.
Answer: The variety of distinct ecosystem types (habitats) within a
region. In some places a wide array of habitats can form a diverse
patchwork of life.
◉ electron transport chain-.
Answer: The last stage of aerobic cellular respiration where the
NADH and FADH2 made in other steps deposit their electrons. As
electrons move down the chain, energy is released and used to move
protons across the mitochondrial membrane to form ATP. At the end
of this process, oxygen acts as the final electron acceptor to form
water.
◉ Electronegativity-.
Answer: The tendancy of an atom to hold shared electrons more
close to its nucleus. Atoms like oxygen have a high electronegativity.
