unit 1 test questions Flashcards
Which structure is part of the endomembrane system?
Golgi apparatus
Which structure is common to plant and animal cells?
mitochondrion
Which of the following is present in a prokaryotic cell?
ribosome
Which of the following components of the phospholipid bilayer are hydrophilic?
phosphate groups
At human body temperature (37°C), cholesterol in membranes functions to
make the membrane less fluid by restricting the movement of phospholipids.
Based on the fluid mosaic model of cell membranes, which of the following statements about membrane phospholipids is true?
They can move laterally along the plane of the membrane.
How do unsaturated fatty acids help keep any membrane more fluid at lower temperatures?
The double bonds form kinks in the fatty acid tails that prevent adjacent lipids from packing tightly together.
The sugars associated with glycoproteins and glycolipids of animal cell membranes
serve as markers that distinguish one cell from another.
Which of the following evolutionary adaptations would you expect to find in the cell membranes of plants that thrive in extremely hot desert environments?
a low percentage of unsaturated fatty acids
Which of the following evolutionary adaptations would you expect to find in the cell membranes of Antarctic icefish?
a high percentage of unsaturated fatty acids
Which of the following types of molecules would be expected to pass through a phospholipid bilayer most readily?
small hydrophobic
Which of the following statements best describes a characteristic feature of diffusion?
It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.
Which of the following statements best explains why water can move quickly through the plasma membrane of certain cells?
It moves through aquaporin channel proteins.
Which of the following statements best describes a characteristic feature of the environments where plant and animal cells typically exist?
Animal cells are generally in an isotonic solution, and plant cells are generally in a hypotonic solution.
Which of the following statements best describes what happens to a plant cell when it is submerged in distilled water?
The cell will become turgid.
Which of the following statements best describes what happens to a red blood cell when it is submerged in distilled water?
The cell will expand and burst.
Which of the following statements best describes what happens to a red blood cell when it is submerged in a hypertonic solution?
The cell will shrivel.
The cytoplasmic side of a cell membrane is negative in charge relative to the extracellular side. What is the voltage across a cell membrane called?
membrane potential
Which of the following statements best describes a primary function of an electrogenic pump in cell membranes, such as the sodium-potassium pump?
generating the membrane potential
The energy required for the sodium-potassium pump is provided by which of the following?
ATP
A bacterium engulfed by a white blood cell through phagocytosis will be digested by enzymes contained in
lysosomes.
Secreted signal molecules that travel only short distances and influence only cells in the immediate vicinity are associated with which of the following signaling pathways?
paracrine signaling
Gated ion channels in neurons are opened in response to neurotransmitters. Neurotransmitters in this example serve as which of the following parts of the signal pathway?
signal molecule
Which of the following enzymes commonly inactivates phosphorylated proteins?
protein phosphatase
