The plasma membrane is made up of a bilayer of phospholipids, which prevent fluids from leaking out of the cell.
It is composed of a single layer of phospholipids.
The molecules that make up the membrane are phospholipids.
The molecules that make up most of the plasma membrane are polar at their heads and tails.
It is a rigid structure that protects the cell like a shell.
The molecules making up the plasma membrane are locked in place.
Simple diffusion involves particles moving from an area of high concentration to an area of lower concentration without the use of energy or helper membrane proteins.
Oxygen moves through the cell membrane from an area of high concentration outside the cell into an area of lower concentration inside the cell.
Glucose is transported into the cell via a transport protein.
Sodium is transported out of the cell to an area of lower concentration with the use of ATP.
Hydrogen ions are pumped out of stomach lining cells with the use of ATP.
The salts in a laxative cause water to move from surrounding cells into the intestines.
The tail portions of each individual molecule are hydrophobic and, therefore, repel water from the inner region of the phospholipid bilayer.
has a net negative charge.
has a high salt concentration.
stores hormones for future use.
contains the head regions of the phospholipid molecules.
is void of water.
Cilia are short, microtubule-based projections often found in large numbers on a single cell. Their sweeping movement can help move the cell and also move fluid along and past a cell.
help the cell move through its environment.
All of the above.
when they are present, occur in large numbers on a single cell.
are short projections.
are microtubule-based structures.
Ribosomes are present in all living cells.
By binding to beta-adrenergic receptors (or beta-receptors) and thereby blocking adrenaline from binding, beta-blocker drugs reduce anxiety.
Transport proteins move molecules into the cell that are not able to diffuse through the membrane. Cystic fibrosis occurs when an individual inherits incorrect genetic instructions for producing a transport protein that controls the flow of chloride ions into and out of cells found primarily in the lungs and digestive tract.
Tight junctions form waterproof seals, and desmosomes function like rivets.
plasmodesmata; gap junctions
tight junctions; desmosomes
desmosomes; tight junctions
gap junctions; tight junctions
Transport proteins provide a passageway for molecules through the cell. A transport protein would allow a molecule of testosterone produced in a testicular cell to move out of the cell and into the bloodstream.
binding to adrenaline on heart cells, thereby increasing the heart's rate of contraction
moving testosterone produced within a testicular cell into the bloodstream
maintaining the flexibility of the cell membrane
recognizing and ingesting a cold virus
initiation of an immune system response upon identifying a foreign cell
Fat cells have very low metabolic activity and thus a low number of mitochondria.
plasmodesmata: nerve cells
plasmodesmata: plant cells
gap junctions: cardiac tissue
desmosomes: muscle tissue
tight junctions: small intestines
All of these statements about cellular fingerprints are actually true. Every cell has a fingerprint made from molecules on its outer surface, and this fingerprint is key to helping the immune system distinguish "self" from "non-self."
All of the following
HIV uses cellular fingerprints to target and infect a person's cells.
It is difficult to transplant an organ from one individual to another because of cellular fingerprints.
Cellular fingerprints explain why a person can't catch HIV from shaking hands.
Cellular fingerprints are how the immune system recognizes and attacks foreign invaders.
Cell division in plants occurs without the centriole. Plant cells are able to make their own food with the presence of chloroplasts. Their cells also can store water and dissolved substances in their large central vacuoles.
Animal cells and plant cells share a common prokaryotic ancestor.
Centrioles are structures always found in plant and animal cells.
Animal cells contain ribosomes, but like prokaryotic cells, plant cells do not.
Centrioles are generally not found in plant cells, and chloroplasts, cell walls, and vacuoles are not found in animal cells.
Animal cells and plant cells are entirely different types of cells, not even sharing a common ancestor.
The lysosomes function as the waste disposal system of the cell.
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