Question 1 of 48
3.75 Points
Decondensed chromatin is located within the
A.nucleolus during maintenance
B.nucleus during cell maintenance
C.nucleus during cell division
D.nucleolus during cell division Reset Selection
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Question 2 of 48
3.75 Points
The evil arch-villain Dr. Black Thumb has created a new plant pathogen. The microbe has an enzyme allowing it to quickly convert β 1-4 glycosidic linkages to α 1-4 glycosidic linkages in a whole field of plants. If Dr. Black Thumb’s plan is not thwarted, crop harvests could be ruined due to
A.amylose and amylopectin becoming hard and inedible.
B.plant starches becoming rigid and popping cell membranes.
C.
plants flopping over.
D.polysaccharides converting into monosaccharides. Reset Selection
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Question 3 of 48
3.75 Points
An atom with an atomic mass of 89 and an atomic number of 39 has how many
neutrons?
A.128
B.2
C.50
D.59 Reset Selection
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Question 4 of 48
3.75 Points
What factors allow a pool of 20 amino acids to produce thousands of unique proteins? (Select all that apply.)
A. variation in length of amino acid backbone
B. each protein is encoded by a distinct gene
C. variation in tertiary structure
D. variations in which amino acids are used
E. variations in glycosidic linkage
F. variations in the type of peptide bond
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Question 5 of 48
3.75 Points
_________________ prevent material from moving in or out of the brain’s capillaries
A.Desmosomes
B.Plasmodesmatas
C.Gap junctions
D.Tight junctions Reset Selection
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Question 6 of 48
3.75 Points
Cardiac muscle requires junctions that allow electrical signals through. Cardiac muscle also relies on calcium to contract. What junction is involved and what organelle stores calcium?
A.desmosomes, smooth ER
B.plasmodesmata, rough ER
C.gap, smooth ER
D.tight, rough ER Reset Selection
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Question 7 of 48
3.75 Points
The building blocks of nucleic acids are
A.sugars.
B.nucleotides.
C.peptides.
D.nitrogenous bases. Reset Selection
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Question 8 of 48
3.75 Points
Which statements describe sodium atoms? Select all that apply.
A. forms cations
B. closest to the left side of the periodic table
C. easily forms covalent bonds
D. contains 1 valence electron
E. has 2 electrons in the first energy level
F. can lose one electron easily
G. outer energy level is stable
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Question 9 of 48
3.75 Points
If an integrin protein is mutated what cell function might be affected?
A.communication between cytoskeleton and proteglycan
B.fluidity of phospholipids
C.cellular motility
D.cytoplasmic communication Reset Selection
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Question 10 of 48
3.75 Points
Buffers are important for doing experiments in labs, but they are not relevant to living systems.
True
False
Reset Selection
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Question 11 of 48
3.75 Points
The cell theory states
A.all cells will contain DNA, all cells are the smallest living things that can divide and all organisms are composed of cells
B.all organisms are composed of multiple cells, all cells arise spontaneously and all cells require nutrients
C.all cells are the smallest living things, all organisms are composed of one or more cells and all cells arise spontaneously
D.all organisms are composed of one or more cells, all cells are the smallest living things and all cells arise from other cells Reset Selection
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Question 12 of 48
3.75 Points
Hiking in the snowy woods, you peek inside a cave and encounter a hibernating grizzly bear! Its metabolic rate seems to be very low. What do you predict is the predominant type of reaction occurring in this bear?
A.fatty acid anabolism
B.carbohydrate catabolism
C.carbohydrate anabolism
D.fatty acid catabolism Reset Selection
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Question 13 of 48
3.75 Points
Rosenberg, a chemist, was observing the effects of an electric field on bacterial growth. He observed that bacteria stopped dividing when in an electric field. This research led to the anti-cancer drug cisplatin, a platinum containing compound. Rosenberg’s discovery was an example of
science.
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Question 14 of 48
3.75 Points
Enzymes are catalysts in reactions. What statements describe functions of enzymes? Select all that apply.
A. Enzymes are specific in their actions.
B. Once an enzyme binds to a substrate, it cannot be used again.
C. Enzymes lower the energy of activation needed for a reaction
D. Enzymes change the amount of free energy produced
E. Enzyme activity can be affected by temperature.
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Question 15 of 48
3.75 Points
In biological macromolecules like proteins, the hydrophobic residues tend to clump together in the interior of the folded structure. What is the best explanation for why this occurs?
A.Polar residues tend to bind to water in the cytoplasm as well as to each other. The water and polar residues cannot bind to the hydrophobic ones, so in the lowest energy state the hydrophobic residues are pushed together in the middle.
B.Protein folding machinery interprets the amino acid code to pack hydrophobic residues into the center of proteins. This process must be important, because the cell expends large amounts of ATP to precisely coordinate protein folding.
C.Hydrophobic residues bind to each other in specific ways. For instance, Ala forms di-methyl bonds, and phenylalanine binds isoleucine. This creates a tightly bound hydrophobic inner core.
D.Hydrophobic residues bind each other, while polar residues cannot bind each other. Therefore the hydrophobic ones end up stuck to each other in the core of the protein. Reset Selection
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Question 16 of 48
3.75 Points
If two solutions are different, the one will the higher concentration of solutes is
A.isotonic
B.hypertonic
C.hypotonic Reset Selection
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Question 17 of 48
3.75 Points
You are designing a museum exhibit to teach people about cells. In the entrance to the exhibit, visitors riding a moving walkway under flashing lights will gradually “shrink” down in size. To create this illusion, visitors will pass giant models of various biological parts, accompanied by scale bars.
Match each model to the appropriate scale bar to go with it.
A. 1 μm
B. 1nm
C. 10μm
D. 1cm
E. 1m
F. 0.1 nm
1. Carbon atom
2. cell nucleus
3. DNA molecule (10bp)
4. human being
5. human eyeball
6. skin cell
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Question 18 of 48
3.75 Points
The fluid mosaic model describes membranes as fluid due to
A.phospholipids sporadically placed throughout the membrane
B.the membrane is mostly composed of water
C.the proteins and the phospholipids can move laterally throughout the membrane
D.higher amounts of cholesterol
E.higher amounts of cholesterol Reset Selection
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Question 19 of 48
3.75 Points
Cholera kills over 100,000 people each year worldwide due to diarrhea. The cholera toxin opens the CFTR chloride channel in the intestines, so that sufferers lose chloride, sodium and massive amounts of water.
On the other hand, the same CFTR channel is mutated in cystic fibrosis patients. With activity too LOW, they lack chloride flow and mucus builds up in the lungs.
This illustrates the importance of precise control of channel opening, known as
____________regulation.
A.gated
B.ungated
C.passive Reset Selection
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Question 20 of 48
3.75 Points
When viewing the shape of a human cheek cell, what microscope would most likely be used?
A.light
B.dissecting
C.transmission electron
D.scanning electron Reset Selection
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Question 21 of 48
3.75 Points
At a meal, you are served a hamburger with cheese, onions, and beef on a bun. What ingredients represent the most carbohydrates? Select all that apply.
A. beef
B. bun
C. onion
D. cheese
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Question 22 of 48
3.75 Points
Estrogen and testosterone are structurally related to cholesterol. Based on what you have learned about cholesterol, predict how these steroid hormones signal to the cell.
A.They are phagocytosed, degraded, and then released into the cell.
B.They make the membrane so fluid that small pores appear, allowing them to pass through.
C.They diffuse directly through the plasma membrane and into the cell.
D.They bind to receptors on the outside of the membrane, which then activate an intracellular signaling cascade. Reset Selection
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Question 23 of 48
3.75 Points
Noncompetitive inhibition occurs when
A.a substance binds at the activity site
B.a substance binds on a site away from the active site
C.denaturing an enzyme
D.increasing the activity of an enzyme Reset Selection
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Question 24 of 48
3.75 Points
Organisms must use macromolecules that have properties to match their functional requirements. In the list below, choose the appropriate macromolecule whose properties meet the requirement.
A. glycogen
B. RNA
C. DNA
D. cellulose
E. starch
1. Requirement:
Strong cell walls
Properties:
Linear polymer rigid and strong
2. Requirement
Stable storage of information
Properties:
4 base pairs, not easily hydrolyzed
3. Requirement:
Energy storage for seeds
Properties:
Energy-rich polysaccharides
4. Requirement:
Short-term energy storage (animals)
Properties:
Energy-rich polysaccharide
5. Requirement:
Transient transmission of information
Properties:
4 base pairs, easily hydrolyzed
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Question 25 of 48
3.75 Points
Membrane proteins are able to cross because sections are composed of
A.nonpolar phosphate regions
B.hydrophilic amino acids.
C.hydrophobic amino acids
D.polar amino acids
E.hydrophilic phosphate regions Reset Selection
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Question 26 of 48
3.75 Points
The shape of the cell is predominantly maintained by the
A.plasma membrane
B.cytoskeleton
C.cytoplasm
D.endomembrane system Reset Selection
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Question 27 of 48
3.75 Points
What is the function of cholesterol in plasma membranes?
A.allows ions to pass
B.regulates pH
C.promotesartherosclerosis
D.regulates fluidity Reset Selection
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Question 28 of 48
3.75 Points
When donating blood, hemoglobin levels are measured by using a narrow glass tube to obtain blood from a finger prick. The blood is pulled up the tube by _____________________.
A.cohesiveness
B.covalent bonds
C.hydrophobic interactions
D.hydrogen bonds
E.ionic bonds Reset Selection
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Question 29 of 48
3.75 Points
What protein is matched with its function?
A.aquaporins – move water through the membrane by active transport
B.carrier protein – nonspecific and will allow material to pass directly through
C.channel protein – allow passage of material through the hydrophilic pore
D.transport proteins – allow passage of material with the aid of ATP
Reset Selection
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Question 30 of 48
3.75 Points
C6H12O6 + 6O2 à 6H2O + 6CO2 is an example of ________________.
A.catabolism
B.anabolism
C.synthesis Reset Selection
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Question 31 of 48
3.75 Points
Carbon-12, Carbon-13, and Carbon-14 are examples of
A.isomers
B.molecules
C.ions
D.isotopes
E.enantiomers Reset Selection
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Question 32 of 48
3.75 Points
What statement(s) describes a concentration gradient?
A. Oxygen in blood plasma is .31 per 100 ml. Oxygen carried with hemoglobin is .69 per 100 ml.
B. Extracellular fluid contains 13.5 mmol of calcium, and 9 mmol of calcium is in the plasma.
C. The temperature inside the car is 39 degrees Celsius and the temperature outside the care is 39 degree Celsius.
D. Red blood cells cytoplasm contains a 0.9% salt solution. The extracellular fluid is 1.0%.
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Question 33 of 48
3.75 Points
How can ice float?
A.the covalent bonds expand, decreasing density
B.the hydrogen bonds expand, decreasing density
C.the covalent bonds collapse, increasing density
D.the hydrogen bonds collapse, increasing density Reset Selection
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Question 34 of 48
3.75 Points
Which of the following form the foundation of plasma membranes?
A.Glycoproteins
B.Fatty acids
C.Glycolipids
D.Phospholipids
E.Proteins Reset Selection
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Question 35 of 48
3.75 Points
You and your roommate are grocery shopping. “I don’t get it,” she says. “My doctor said I should buy this special milk because I don’t digest it well. But this brand says ‘lactose-free’ and this brand says ‘lactase added’ – which do I want?”
You reply: “The
_______________ is a sugar in milk that you have trouble digesting, and
_________________ is an enzyme that will digest it for you.
A.lactase, lactose
B.lactose,lactase Reset Selection
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Question 36 of 48
3.75 Points
If sodium does not move down its gradient in the co-transport pump, what would be the outcome?
A.Sugar would not be affected
B.Sugar would not be able to move down the gradient
C.Sugar would not be able to move up the gradient Reset Selection
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Question 37 of 48
3.75 Points
When phospholipids are placed in water, why does a bilayer form?
A.Phospholipids are naturally attracted to each other, forcing phosphate heads to face the aqueous areas.
B.The fatty acid tails are forced together away from the water, and water can create hydrogen bonds with the phosphate heads.
C.Lipids are hydrophilic and will from hydrogen bonds with the water, forcing the hydrophobic heads towards the middle of the bilayer.
D.The polar tails will be attracted to the water and the nonpolar heads will be attracted to each other. Reset Selection
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Question 38 of 48
3.75 Points
To break chemical bonds to start a chemical reaction, ___________ energy is needed.
A.kinetic
B.potential
C.activation
D.free Reset Selection
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Question 39 of 48
3.75 Points
The microbiologist Louis Pasteur invented pasteurization, created vaccines for anthrax and rabies, and helped explain the germ theory of disease. He is often quoted as saying, “Chance favors the prepared mind.” A more accurate translation from the French, however, is “Where observation is concerned, chance favors only the prepared mind.” What can you conclude about Pasteur’s attitude about the role of chance in scientific discovery?
A.He thought that chance events are only useful if someone is intelligent enough to understand what happened.
B.He thought that observation of something unique doesn’t do any good if the scientist is not prepared to interpret and follow up on the chance discovery, due to a habit of studious work.
C.He thought you would have to be lucky to notice a chance event.
D.He thought that chance is the main determinant of who is successful in science, so all you can do is hope you get lucky. Reset Selection
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Question 40 of 48
3.75 Points
A tarantula has eight legs, an arachnid in the order Araneae. A grass spider has eight legs, an arachnid in the order Araneaa. A mouse spider has eight legs, an arachnid in the order Araneae. There is a pattern. All organisms in this order have eight legs. This is
reasoning
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Question 41 of 48
3.75 Points
In a chocolate bar with nuts and caramel, there are 12 grams of fat, 33 grams of carbohydrates and 4 grams of protein. What percentage of calories comes from fat?
A.6.5%
B.19%
C.53%
D.41 Reset Selection
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Question 42 of 48
3.75 Points
Normal (homeostatic) pH level of blood serum’s pH is around 7.4. Carbonic acid is released in the blood to help maintain a pH that has high hydroxyl levels. This would cause pH to change from
A.basic to acidic
B.basic to neutral
C.neutral to basic
D.acidic to 7.4
E.basic to 7.4 Reset Selection
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Question 43 of 48
3.75 Points
What is the pathway in which a protein moves through the endomembrane system?
A.rough ER, Golgi apparatus, smooth ER, transport vesicle, plasma membrane
B.plasma membrane, transport vesicle, Golgi apparatus, rough ER
C.rough ER, Golgi apparatus, transport vesicle, plasma membrane
D.smooth ER, Golgi apparatus, transport vesicle, plasma membrane Reset Selection
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Question 44 of 48
3.75 Points
Molecules move from a high to low concentration in
A.isotonic solutions
B.hypotonic solutions
C.hypertonic solutions
D.diffusion
E.osmosis Reset Selection
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Question 45 of 48
3.75 Points
What examples describe the second law of thermodynamics? Select all that apply.
A. A penny will fall when you pick it up and let it drop.
B. A frying pan is on a hot stove. When removed it will cool.
C. Ice cubes will melt in a warm room.
D. Donuts nutrients are used to help you exercise.
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Question 46 of 48
3.75 Points
Researchers are working to develop biofuels to free us from dependence on fossil fuels. Based on what you know about cellulose, what do you predict are the major advantage and disadvantage of using cellulose-rich plant material as biofuel?
A.There is not much energy in the glycosidic bonds of cellulose, but at least there is a lot of it.
B.There is not much energy in the peptide bonds of cellulose, but at least it is very easy to break down
C.The breakdown of cellulose into fructose is an endergonic reaction, but an enzyme can reverse the equilibrium.
D.Cellulose is very difficult to break down into glucose, but it contains a lot of energy. Reset Selection
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Question 47 of 48
3.75 Points
The impermeability of cell plasma membranes is a major barrier to using drugs to kill tumor cells or affect cells transgenically. CPPs are peptides that were discovered to have the ability to transport themselves (and even attached cargo) into cells. How they get into cells is still a mystery, but CPPs all have multiple positively charged groups. Which of the following membrane components are they most likely to be interacting with?
A.cholesterol
B.intrinsic membrane proteins
C.phospholipid heads
D.phospholipid tails Reset Selection
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Question 48 of 48
3.75 Points
Which of the following is an example of an aliphatic hydrocarbon?
A.Benzene
B.Estrogen
C.Cholesterol
D.Methane
