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Q&A VERIFIED ANSWERS
It is true that a eukaryotic cell
A. is smaller than a prokaryotic cell.
B. contains structures calledorganelles.Correct
C. lacks a well-defined nucleus.
D. does not contain histones.
Eukaryotic cells contain organelles and histones, they have a well-defined nucleus, and
are larger than prokaryotic cells.
The function of a histone found in a eukaryote cell focuses on cellular
A. division.
B. movement.
C. activities.
D. deoxyribonucleic acid (DNA) folding.Correct
The histones are binding proteins that cause the supercoiling of DNA into chromosomes
and do not affect cellular division, movement, or activities.
An organelle that is responsible for the metabolism of cellular energy is referred to as
a/an
A. Golgi complex.
B. mitochondrion.Correct
C. endoplasmic reticulum.
D. nucleolus.
Mitochondria play a role in cellular metabolism, cellular respiration, and energy
production. The Golgi complex is responsible for processing and packaging proteins
from the endoplasmic reticulum, where they are synthesized. The nucleolus is a small,
dense structure that contains the ribonucleic acid (RNA), DNA, and DNA-binding
proteins.
Which statementbestdescribes a desmosome?
A. A desmosome is a barrier to diffusion.
B. Desmosomes hold cells together by continuous bands.Correct
C. A desmosome is a communicating tunnel.
D. Desmosomes function as a zona occludens.
The desmosome is a type of cell junction. The other two types include tight junctions
and gap junctions. Desmosomes hold cells together by forming a continuous band of
epithelial tissue or belt (or button-like) points of contact. They are also a source of
,s tructural stability. Tight junctions serve as barriers to diffusion and prevent the
movement of substances through transport proteins. Gap junctions are clusters of
communicating tunnels.
Which statement describes the function of a second messenger?
A. Binds with membrane-bound receptors via a ligand
B. Triggers a cascade of intracellular eventsCorrect
C. Opens specific channels in the cell membrane
Blocks a membrane-bound receptor signal
The binding of a ligand to a cell surface receptor triggers the activation of intracellular
second messengers. Second messengers activate signal transduction pathways in the
cell that can initiate different intracellular events. Cyclic adenosine monophosphate
(cAMP) and calcium (Ca++) are the two major second-messenger pathways. First
messengers are the extracellular ligands that bind to cell surface receptors. Binding of
first messengers can result in the opening or closing of specific cell membrane channels
or the activation of second messengers.
Which statement iscorrectregarding cellular energy?
A. Glycolysis is the building of sugar molecules.
B. Oxidative cellular metabolism is a single reaction making adenosine triphosphate
(ATP).
C. Oxidative phosphorylation occurs in the mitochondria.Correct
D. Anaerobic glycolysis occurs in the presence of oxygen.
Oxidative phosphorylation occurs in the mitochondria. This is the mechanism by which
the energy produced from carbohydrates, fats, and proteins is transferred to ATP.
Glycolysis is a process that breaks down glucose molecules; it produces a net of two
ATP molecules. Oxidation is a process during which a pair of electrons are removed
and transferred. Oxidative cellular metabolism involves 10 biochemical reactions.
Anaerobic glycolysis occurs in the absence of oxygen.Aerobicmeans in the presence
of oxygen.
Movement of a solute molecule from an area of high concentration to an area of low
concentration is called
A. diffusion.Correct
B. filtration.
C. osmosis.
D. hydrostatic pressure.
Diffusion is the movement of a solute from an area of high concentration to an area of
low concentration. Osmosis is the movement of water down a concentration gradient
from an area of higher water concentration to an area of lower water concentration.
Filtration is the movement of water and solute through a membrane because of a
greater pushing pressure on one side of the membrane than the other. Hydrostatic
pressure is the mechanical force of water pushing against a cell membrane.
, hich is an example of an energy-releasing process?
W
A. Anabolism
B. CatabolismCorrect
C. Substrate-induced reaction
D. Second messenger system
Catabolism is an energy-releasing process. The energy-using process is anabolism. A
substrate is a specific substance that is converted to a product in the reaction. A second
messenger is a "pass-it-on signal." This occurs when a first messenger activates a
receptor that then triggers a pass-it-on signal.
Which describes an amphipathic molecule?
A. It is permeable to water only.
B. It is a nonpolar molecule.
C. It is both hydrophobic and hydrophilic.Correct
D. It is a one-layered structure.
The amphipathic molecule is both hydrophobic and hydrophilic. A hydrophilic molecule
is a charged, water-loving molecule. A hydrophobic molecule is an uncharged or
water-hating molecule. A polar molecule is another name for an amphipathic molecule.
Which are the roles of relay chains in signal transduction?(Select all that apply.)
A. Transfer the signalCorrect
B. Converge the signal
C. Amplify the signalCorrect
D. Distribute the signalCorrect
The functions of relay chains include transferring the signal from its reception point to
another part of the cell where it is expected; amplifying the signal received and making it
stronger; and distributing the signal so that it influences several processes in parallel.
The signal can diverge, not converge, and be relayed to several different intracellular
targets
Which are functions of a protein?(Select all thatapply.)
A. Pores or transport channelsCorrect
B. Enzymes that drive pumpsCorrect
C. Cell surface markersCorrect
D. Synapses for cells
Proteins may act as transport channels, pores, cell surface markers, enzymes that drive
pumps, catalysts, and cell adhesion molecules (CAMs), or they may act as the key
components of ATP synthesis. Synapses are the connections between two nerve cells.
What is a collection of blood that is located between the skull and the dura is called?
A. Epidural hematomaCorrect
B. Contusion
C. Subdural hematoma
D. Subarachnoid hemorrhage