What are the three types of protein fibers that make up the cytoskeleton?
microtubules, intermediate filaments, and microfilaments
Which of the following statements about the cell theory is correct?
All living organisms are made up of one or more cells.
All cells arise from other, pre-existing cells
Drugs called beta-blockers do all of the following except:
bind to the cytoplasmic side of a receptor protein.
reduce outward symptoms of anxiety.
block signaling through adrenaline receptors.
reduce high blood pressure.
bind to the cytoplasmic side of a receptor protein.
In an experiment, you measure the concentration of a polar molecule inside and outside a cell. You find that the concentration is high and gradually increasing inside the cell. You also measure the ATP concentration inside the cell and find that it is dropping. What is your best hypothesis for the process you are observing?
active transport
Which of the following allows the passage of small molecules between animal cells? tight junctions desmosomes nucleoli black holes
gap junctions
Which of the following types of human cells does NOT contain DNA?
red blood cells
What cellular structure makes it possible for a cell to differ structurally and biochemically from its surroundings? phospholipid plasma membrane endoplasmic reticulum nucleus cell wall
plasma membrane
If the solution surrounding a cell contains the same amount of solute as the cytoplasm, the osmotic condition is said to be:
isotonic
An ostrich egg is to a cell as:
a giant sequoia is to a tree.
Correct! The ostrich egg is the largest type of cell, whereas the giant sequoia is the largest type of tree.
What cellular structure makes it possible for a cell to differ structurally and biochemically from its surroundings
plasma membrane
______________ are found in all metabolically active cells and are involved primarily in transporting materials within, into, and out of cells.
vesicles
mitochondria have their own..
dna
Which of the following is NOT true about prokaryotic cells?
They have a circular loop of DNA instead of multiple linear DNA molecules.
They are always single-celled organisms, and they never contain mitochondria.
They have a rigid cell wall instead of a plasma membrane.
They may have flagella, but they never have cilia.
They lack a nucleus, but they do have ribosomes.
They have a rigid cell wall instead of a plasma membrane.
Which of the following statements is TRUE about a plasma membrane?
The molecules that make up the membrane are phospholipids.
It is a rigid structure that protects the cell like a shell.
The molecules that make up most of the plasma membrane are polar at their heads and tails.
It is composed of a single layer of phospholipids.
The molecules making up the plasma membrane are locked in place.
The molecules that make up the membrane are lipids.
The transport of water across a membrane from a solution of lower solute concentration to a solution of higher solute concentration is best described as:
osmosis
Which is NOT true about chloroplasts and mitochondria?
mitochondria break down food energy to make ATP
animal cells don’t have chloroplasts
chloroplasts produce food from sunlight energy
plants have chloroplasts instead of mitochondria
both mitochondria and chloroplasts are involved with energy transformation
plants have chloroplasts instead of mitochondria
Which of the following statements is correct?
Centrioles are structures found in both plant and animal cells.
Centrioles are 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.
Animal cells and plant cells share a common prokaryotic ancestor.
Animal cells contain ribosomes, but like prokaryotic cells, plant cells do not.
Centrioles are not found in plant cells, and chloroplasts, cell walls and vacuoles are not found in animal cells.
Drugs called beta-blockers do all of the following except:
block signaling through adrenaline receptors.
reduce the effects of adrenaline on the heart.
reduce high blood pressure.
bind to the cytoplasmic side of a receptor protein.
reduce outward symptoms of anxiety.
bind to the cytoplasmic side of a receptor protein.
The movement of molecules across a membrane from an area of high concentration to one of low concentration is best described as:
passive transport
How do beta-blockers function to reduce anxiety?
The drugs bind to beta-adrenergic receptors and block adrenaline from having any function.
The role of cholesterol in the plasma membrane of animal cells is to:
keep the plasma membrane flexible, especially at low temperatures.
Endosymbiosis
According to this theory, mitochondria and chloroplast are thought to have originally been prokaryotes capable of cellular respiration and photosynthesis, respectively, that were engulfed by a cell that developed into a eukaryotic cell.
invagination
the cell membrane folded in on itself to form inner compartments that specialized to become the membranous organelles
why is it called a mosaic?
The plasma membrane behaves like a fluid because many membrane molecules can move around within their respective layer of the phospholipid bilayer, and it is described as a mosaic because it is composed of a variety of proteins, lipids, and carbohydrates
- The Golgi apparatus:
processes and packages proteins, lipids, and other molecules.
Diffusion across the cell’s outer membrane:
occurs without an input of energy
Which statement is NOT part of the modern cell theory?
Cells are able to synthesize their entire complement of biomolecules.
In Tay-Sachs disease, a genetic mutation causes a malfunction in a certain organelle that leads to a backup of molecules and proteins, ultimately interfering with the entire functioning of the cell. Which organelle is primarily affected by this disease?
Lysosomes
A scientist tries to build a eukaryotic cell in her laboratory. She remembers to include most of the organelles, but forgets one. Among other abnormalities, her newly created cell cannot synthesize the enzymes needed to detoxify drugs and poisons. Which organelle is missing?
smooth er
Which of the following is NOT true about prokaryotic cells?
all have a rigid cell wall instead of a plasma membrane
The pH of the liquid inside a lysosome is acidic, about 4.5. The molecules normally found inside the lysosome are designed to work best at this pH. Which of the follow statements is the BEST explanation for why the pH of the lysosome interior is so low?
Protective: if the corrosive broth of a lysosome ever leaked out, the digestive enzymes in it would become non-functional in the higher pH of the cytoplasm
Which of the following is NOT a correct statement about passive transport across the cell membrane?
Passive transport increases entropy in a system.
Cellular “fingerprints”:
can help the immune system distinguish “self” from “non-self.
Which of the following describes pinocytosis?
A cell performs endocytosis, bringing in dissolved particles and liquids.
smooth er function
synthesizes lipids and detoxifies molecules.
Facilitated diffusion of magnesium ions (Mg++) would occur OUT of a cell if the Mg++ concentration was ________ outside the cell than inside, and ________
lower, Mg++ could move directly through the phospholipid bilayer of the membrane
The “fingerprint” found on the outsides of cells is the BEST underlying explanation for:
why you can’t catch HIV by casual contact
In chemistry class we learn the rule “like dissolves like” when studying why polar substances dissolve in each other (like sucrose in water) and why non-polar substances dissolve in each other (like fats in oil). Which of the following statements illustrates this rule?
Transmembrane proteins remain in the plasma membrane even though they are not attached to anything.
pinocytosis?
A cell performs endocytosis, bringing in dissolved particles and liquids.
Which of the following organelles contains a small circular loop of DNA
mitochondria
