Biology 111

Pregunta 1 de 94

1

A cell has enough available ATP to meet its needs for about 30 seconds. What is likely to happen when an athlete exhausts his or her ATP supply?

Selecciona una de las siguientes respuestas posibles:

ATP is transported into the cell from the circulatory system.
Other cells take over, and the muscle cells that have used up their ATP cease to function.
Catabolic processes are activated that generate more ATP.
He or she has to sit down and rest.

Explicación

Pregunta 2 de 94

1

A number of systems for pumping ions across membranes are powered by ATP. Such ATP-powered pumps are often called ATPases, although they do not often hydrolize ATP unless they are simultaneously transporting ions. Because small increases in calcium ions in the cytosol can trigger a number of different intracellular reactions, cells keep the cytosolic calcium concentration quite low under normal conditions, using ATP-powered calcium pumps. For example, muscle cells transport calcium from the cytosol into the membranous system called the sarcoplasmic reticulum (SR). If resting muscle cell's cytosol has a free calcium ion concentration of 10^(-7) while the concentration in the SR is 10^(-2), then how is the ATPase acting?

Selecciona una de las siguientes respuestas posibles:

ATPase activity must be opening a channel for the calcium ions to diffuse back into the SR along the concentration gradient.
ATPase activity must be pumping calcium from the cytosol to the SR against the concentration gradient.
ATPase activity must be powering an inflow of calcium from the outside of the cell into the SR.
ATPase activity must be transferring Ⓟi to the SR to enable this to occur.

Explicación

Pregunta 3 de 94

1

Cell membranes are asymmetrical. Which of the following statements is the most likely explanation for the membrane's asymmetrical nature?

Selecciona una de las siguientes respuestas posibles:

The two sides of a cell membrane face different environments and carry out different functions.
Since the cell membrane forms a border between one cell and another in tightly packed tissues such as epithelium, the membrane must be asymmetrical.
Since cell membranes communicate signals from one organism to another, the cell membranes must be asymmetrical.
Proteins only function on the cytoplasmic side of the cell membrane, which results in the membrane's asymmetrical nature.

Explicación

Pregunta 4 de 94

1

Fatty acids usually have an even number of carbons in their structures. They are catabolized by a process called beta-oxidation. The end products of the metabolic pathway are acetyl groups of acetyl CoA molecules. These acetyl groups ________.

Selecciona una de las siguientes respuestas posibles:

directly enter the energy-yielding stages of glycolysis.
directly enter the electron transport chain.
are directly decarboxylated by pyruvate dehydrogenase.
directly enter the citric acid cycle.

Explicación

Pregunta 5 de 94

1

If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence ______.

Selecciona una de las siguientes respuestas posibles:

3'UAACGU5'
5'UGCAAU3'
5'TAACGT3'
5'TGCAAT3'

Explicación

Pregunta 6 de 94

1

In solution, why do hydrolysis reactions occur more readily than condensation reactions?

Selecciona una de las siguientes respuestas posibles:

Hydrolysis raises G, or Gibbs free energy.
Hydrolysis increases entropy and is endergonic.
Hydrolysis increases entropy and is exergonic.
Hydrolysis decreases entropy and is exergonic.

Explicación

Pregunta 7 de 94

1

Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?

Selecciona una de las siguientes respuestas posibles:

As a consequence of growing, organisms cause a greater increase in entropy in their environment than the decrease in entropy associated with their growth.
Living organisms are able to transform energy into entropy.
Life obeys the second law of thermodynamics because the decrease in entropy as the organism grows is exactly balanced by an increase in the entropy of the universe.
Living organisms do not obey the second law of thermodynamics, which states that entropy must increase with time.

Explicación

Pregunta 8 de 94

1

Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this probably mean?

Selecciona una de las siguientes respuestas posibles:

Proton pumps are necessary to all cell membranes.
Cells of each domain evolved proton pumps independently when oceans became more acidic.
Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life.
The high concentration of protons in the ancient atmosphere must have necessitated a pump mechanism.

Explicación

Pregunta 9 de 94

1

The membranes of winter wheat are able to remain fluid when it is extremely cold by _____.

Selecciona una de las siguientes respuestas posibles:

increasing the percentage of cholesterol molecules in the membranes
decreasing the number of hydrophobic proteins in the membrane
cotransport of glucose and hydrogen
increasing the percentage of unsaturated phospholipids in the membrane

Explicación

Pregunta 10 de 94

1

The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of ______.

Selecciona una de las siguientes respuestas posibles:

allosteric regulation
active transport
a reaction with a positive delta G
an endergonic reaction coupled to an exergonic reaction

Explicación

Pregunta 11 de 94

1

Which of the following processes includes all others?

Selecciona una de las siguientes respuestas posibles:

passive transport
osmosis
facilitated diffusion
transport of an ion down its electrochemical gradient

Explicación

Pregunta 12 de 94

1

Why is glycolysis considered to be one of the first metabolic pathways to have evolved?

Selecciona una de las siguientes respuestas posibles:

It requires the presence of membrane-enclosed cell organelles found only in eukaryotic cells.
It is found in prokaryotic cells but not in eukaryotic cells.
It does not involve organelles or specialized structures, does not require oxygen, and is present in most organisms.
It produces much less ATP than does oxidative phosphorylation.

Explicación

Pregunta 13 de 94

1

A localized group of organisms that belong to the same species is called a

Selecciona una de las siguientes respuestas posibles:

biosystem
community
population
ecosystem
family

Explicación

Pregunta 14 de 94

1

Organisms interact with their environments, exchanging matter and energy. For example, plant chloroplasts convert the energy of sunlight into

Selecciona una de las siguientes respuestas posibles:

the energy of motion
carbon dioxide and water
the potential energy of chemical bonds
oxygen
kinetic energy

Explicación

Pregunta 15 de 94

1

The main source of energy for producers in an ecosystem is

Selecciona una de las siguientes respuestas posibles:

light energy
kinetic energy
thermal energy
chemical energy
ATP

Explicación

Pregunta 16 de 94

1

Which of the following types of cells utilize deoxyribonucleic acid (DNA) as their genetic material but do not have their DNA encased within a nuclear envelope?

Selecciona una de las siguientes respuestas posibles:

animal
plant
archaea
fungi
protists

Explicación

Pregunta 17 de 94

1

To understand the chemical basis of inheritance, we must understand the molecular structure of DNA. This is an example of the application of which concept to the study of biology?

Selecciona una de las siguientes respuestas posibles:

evolution
emergent properties
reductionism
the cell theory
feedback regulation

Explicación

Pregunta 18 de 94

1

Once labor begins in childbirth, contractions increase in intensity and frequency until delivery. The increasing labor contractions of childbirth are an example of which type of regulation?

Selecciona una de las siguientes respuestas posibles:

a bioinformatic system
positive feedback
negative feedback
feedback inhibition
enzymatic catalysis

Explicación

Pregunta 19 de 94

1

When the body's blood glucose level rises, the pancreas secretes insulin and, as a result, the blood glucose level declines. When the blood glucose level is low, the pancreas secretes glucagon and, as a result, the blood glucose level rises. Such regulation of the blood glucose level is the result of

Selecciona una de las siguientes respuestas posibles:

catalytic feedback
positive feedback
negative feedback
bioinformatic regulation
protein-protein interactions

Explicación

Pregunta 20 de 94

1

The elongation of the leading strand during DNA replication

Selecciona una de las siguientes respuestas posibles:

Proceeds away from the replication fork
Depends upon the action of DNA polymerase
Proceeds in the 3' to 5' direction
Does not require a template strand

Explicación

Pregunta 21 de 94

1

What does the reactivity of an atom depend on?

Selecciona una de las siguientes respuestas posibles:

Number of valence shells in the atom.
Number of orbitals found in the atom.
Number of electrons in each orbital in the atom.
Presence of unpaired electrons in the outer valance shell of the atom.
Presence of the hybridized orbitals in the atom.

Explicación

Pregunta 22 de 94

1

A covalent chemical bond is one in which...

Selecciona una de las siguientes respuestas posibles:

electrons are removed from one atom and transferred to another atom so that the two atoms become oppositely charged.
protons and neutrons are shared by two atoms so as to satisfy the requirements of both atoms.
outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shell of both atoms.
outer-shell electrons of an atom are transferred to the inner electron shells of another atom.
the inner-shell electrons of one atom are transferred to the outer-shell of another atom.

Explicación

Pregunta 23 de 94

1

Which of the following is the best example of gene expression?

Selecciona una de las siguientes respuestas posibles:

A frog adapts to variation in its environmental temperature.
Mouse fur color results from pigment formed by gene-encoded enzymes.
DNA is replicated during the S phase of the cell cycle.

Explicación

Pregunta 24 de 94

1

What results from an unequal sharing of electrons between atoms?

Selecciona una de las siguientes respuestas posibles:

A nonpolar covalent bond.
A polar covalent bond.
An ionic bond.
A hydrogen bond.
A hydrophobic interaction.

Explicación

Pregunta 25 de 94

1

Which bonds must be broken for water to vaporize?

Selecciona una de las siguientes respuestas posibles:

Ionic bonds
Nonpolar covalent bonds
Polar covalent bonds
Hydrogen bonds
Covalent bonds

Explicación

Pregunta 26 de 94

1

One liter of a solution of pH has how many more hydrogen ions (H+) than 1L of a solution of pH 6?

Selecciona una de las siguientes respuestas posibles:

4 times more
400 times more
4,000 times more
10,000 times more
100,000 times more

Explicación

Pregunta 27 de 94

1

Observe the structure of glucose and fructose in the figure. These two molecules are...

Selecciona una de las siguientes respuestas posibles:

geometric isomers
enantiomers
structural isomers
nonisotopic isomers

Explicación

Pregunta 28 de 94

1

Polymers of polysaccharides, fats and proteins are all synthesized from monomers by which process?

Selecciona una de las siguientes respuestas posibles:

Connecting monosaccharides together (condensation reactions)
The addition of water to each monomer (hydrolysis)
The removal of water (dehydration reactions)
Ionic bonding of the monomers
The formation of disulfide between monomers

Explicación

Pregunta 29 de 94

1

The 20 different amino acids found in polypeptides exhibit different chemical and physical properties because of different

Selecciona una de las siguientes respuestas posibles:

Carboxyl groups attached to an alpha (α) carbon
Amino groups attached to an alpha (α) carbon
Side chains (R groups)
Alpha (α) carbons
Asymmetric carbons

Explicación

Pregunta 30 de 94

1

The tertiary structure of a protein is the...

Selecciona una de las siguientes respuestas posibles:

bonding together of several polypeptide chains by weak bonds.
order in which amino acids are joined in a polypeptide chain.
unique three-dimensional shape of the fully folded polypeptide.
organization of a polypeptide chain into a a-helix or B-pleated sheet.

Explicación

Pregunta 31 de 94

1

Which of the following best describes the flow of information in eukaryotic cells?

Selecciona una de las siguientes respuestas posibles:

DNA → RNA → Proteins
RNA → Proteins → DNA
Proteins → DNA → RNA
RNA → DNA → Proteins
DNA → Proteins → RNA

Explicación

Pregunta 32 de 94

1

Which of the following are nitrogenous bases found in DNA?

Selecciona una o más de las siguientes respuestas posibles:

thymine
adenine
uracil
guanine
cytosine

Explicación

Pregunta 33 de 94

1

Which of the following types of molecules are the major structural components of the cell's membrane?

Selecciona una o más de las siguientes respuestas posibles:

Phospholipids
Cellulose
Nucleic Acids
Proteins
Cholesterol
Glycoproteins

Explicación

Pregunta 34 de 94

1

The movement of a substance across a biological membrane against its concentration gradient with the help of energy input is...

Selecciona una o más de las siguientes respuestas posibles:

Diffusion
Active transport
Osmosis
Facilitated diffusion
Exocytosis

Explicación

Pregunta 35 de 94

1

The sodium-potassium is called an electrogenic pump because it...

Selecciona una de las siguientes respuestas posibles:

Pumps equal quantities of Na+ and K+ across the membrane.
Pumps hydrogen ions out of cells.
Contributes to the membrane potential.
Ionizes sodium and potassium atoms.
Is used to drive the transport of other molecules against a concentration gradient.

Explicación

Pregunta 36 de 94

1

Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?

Selecciona una de las siguientes respuestas posibles:

Catalysis
Metabolism
Anabolism
Dehydration
Catabolism

Explicación

Pregunta 37 de 94

1

Which of the following statements regarding ATP is (are) correct?

Selecciona una o más de las siguientes respuestas posibles:

ATP serves as a main energy shuttle inside cells.
ATP drives endergonic reactions in the cell by the enzymatic transfer of the phosphate group to specific reactants.
The regeneration of ATP from ADP and phosphate is an endergonic reaction.

Explicación

Pregunta 38 de 94

1

In addition to ATP, what are the end products of glycolysis?

Selecciona una de las siguientes respuestas posibles:

CO2 and H2O
CO2 and pyruvate
NADH and pyruvate
CO2 and NADH
H2O, FADH2, and citrate

Explicación

Pregunta 39 de 94

1

The primary role of oxygen in cellular respiration is to...

Selecciona una de las siguientes respuestas posibles:

Yield energy in the form of ATP as it is passed down the respiratory chain.
Act as an acceptor for the electrons and hydrogen.
Combine with carbon, forming CO2.
Combine with lactate, forming pyruvate.
Catalyze the reactions of glycolysis.

Explicación

Pregunta 40 de 94

1

From the perspective of the cell receiving the message, the three stages of cell signaling are...

Selecciona una de las siguientes respuestas posibles:

The paracrine, local, and synaptic stages
Signal reception, signal transduction, and cellular response
Signal reception, nucleus disintegration, and new cell generation
The alpha, beta, and gamma stages
Signal reception, cellular response, and cell division

Explicación

Pregunta 41 de 94

1

Which of the following is/are true of ligand-gated ion channels?

Selecciona una o más de las siguientes respuestas posibles:

They are important in the nervous system.
They lead to changes in sodium and calcium concentration in cells.
They open or close in response to a chemical signal.

Explicación

Pregunta 42 de 94

1

Which of the following is true of the process of meiosis?

Selecciona una de las siguientes respuestas posibles:

Two diploid cells result
Four diploid cells result
Four haploid cells result
Four autosomes result
Four chiasmata result

Explicación

Pregunta 43 de 94

1

What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants?

Selecciona una de las siguientes respuestas posibles:

There is considerable genetic variation in garden peas.
Traits are inherited in discrete units, and are not the results of "blending".
Recessive genes occur more frequently in the F1 than do dominant ones.
Genes are composed of DNA.
An organism that is homozygous for many recessive traits is at a disadvantage.

Explicación

Pregunta 44 de 94

1

The leading and the lagging strands differ in that

Selecciona una de las siguientes respuestas posibles:

The leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction
The leading strand is synthesized by adding nucleotides to the 3' end of the growing strand, and the lagging strand is synthesized by adding nucleotides to the 5' end.
The leading strand is synthesized continuously, whereas the lagging strand is synthesized in short fragments that are ultimately stitched together.

Explicación

Pregunta 45 de 94

1

RNA polymerase and DNA polymerase differ in that

Selecciona una de las siguientes respuestas posibles:

RNA polymerase uses RNA as a template and DNA polymerase uses a DNA template
RNA polymerase binds to single-stranded DNA and DNA polymerase binds to double-stranded DNA
RNA polymerase is much more accurate than DNA polymerase
RNA polymerase can initiate RNA synthesis but DNA polymerase requires a primer to initiate DNA synthesis.
RNA polymerase does not need to separate the two strands of DNA in order to synthesize an RNA copy, whereas DNA polymerase must unwind the double helix before it can replicate the DNA.

Explicación

Pregunta 46 de 94

1

A frameshift mutation could result from...

Selecciona una de las siguientes respuestas posibles:

a base insertion only
a base deletion only
a base substitution only
deletion of three consecutive bases
either an insertion or a deletion of a base

Explicación

Pregunta 47 de 94

1

Thylakoids are present in chloroplasts.

Selecciona uno de los siguientes:

VERDADERO
FALSO

Explicación

Pregunta 48 de 94

1

The presence of cholesterol in the plasma membranes of some animals

Selecciona una de las siguientes respuestas posibles:

enables the membrane to stay fluid more easily when cell temperature drops.
enables the animal to remove hydrogen atoms from saturated phospholipids.
enables the animal to add hydrogen atoms to unsaturated phospholipids.
makes the membrane less flexible, allowing it to sustain greater pressure from within the cell.
makes the animal more susceptible to circulatory disorders.

Explicación

Pregunta 49 de 94

1

According to the fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids?

Selecciona una de las siguientes respuestas posibles:

They can move laterally along the plane of the membrane.
They frequently flip-flop from one side of the membrane to the other.
They occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane.
They are free to depart from the membrane and dissolve in the surrounding solution.
They have hydrophilic tails in the interior of the membrane.

Explicación

Pregunta 50 de 94

1

What kinds of molecules pass through a cell membrane most easily?

Selecciona una de las siguientes respuestas posibles:

large and hydrophobic
small and hydrophobic
large polar
ionic
monosaccharides such as glucose

Explicación

Pregunta 51 de 94

1

Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly?

Selecciona una de las siguientes respuestas posibles:

CO2
an amino acid
glucose
K+
starch

Explicación

Pregunta 52 de 94

1

Molecules with which functional groups may form polymers via dehydration reactions?

Selecciona una o más de las siguientes respuestas posibles:

hydroxyl groups
carbonyl groups
carboxyl groups

Explicación

Pregunta 53 de 94

1

Which of these molecules is not formed by dehydration reactions?

Selecciona una de las siguientes respuestas posibles:

Fatty acids
Disaccharides
DNA
Protein
Amylose

Explicación

Pregunta 54 de 94

1

Which of these classes of biological molecules consist of both small molecules and macromolecular polymers?

Selecciona una de las siguientes respuestas posibles:

lipids
carbohydrates
proteins
nucleic acids

Explicación

Pregunta 55 de 94

1

Which of the following is not a polymer?

Selecciona una de las siguientes respuestas posibles:

glucose
starch
cellulose
chitin
DNA

Explicación

Pregunta 56 de 94

1

How many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long?

Selecciona una de las siguientes respuestas posibles:

12
11
10
9
8

Explicación

Pregunta 57 de 94

1

Which of the following are polysaccharides?

Selecciona una o más de las siguientes respuestas posibles:

lactose
glycogen
chitin
cellulose
amylopectin

Explicación

Pregunta 58 de 94

1

The bonding of two amino acid molecules to form a larger molecule requires which of the following?

Selecciona una de las siguientes respuestas posibles:

Removal of a water molecule
Addition of a water molecule
Formation of a glycosidic bond
Formation of a hydrogen bond
Both removal of a water molecule and formation of a hydrogen bond

Explicación

Pregunta 59 de 94

1

Upon chemical analysis, a particular polypeptide was found to contain 100 amino acids. How many peptide bonds are present in this protein?

Selecciona una de las siguientes respuestas posibles:

101
100
99
98
97

Explicación

Pregunta 60 de 94

1

What methods may be used to elucidate the structures of purified proteins?

Selecciona una o más de las siguientes respuestas posibles:

X-ray crystallography
bioinformatics
analysis of amino acid sequence of small fragments
NMR spectroscopy

Explicación

Pregunta 61 de 94

1

One of the primary functions of RNA molecules is to

Selecciona una de las siguientes respuestas posibles:

transmit genetic information to offspring.
function in the synthesis of proteins.
make a copy of itself, thus ensuring genetic continuity.
act as a pattern or blueprint to form DNA.
form the genes of higher organisms.

Explicación

Pregunta 62 de 94

1

The element present in all organic molecules is

Selecciona una de las siguientes respuestas posibles:

Hydrogen
Oxygen
Carbon
Nitrogen
Phosphorus

Explicación

Pregunta 63 de 94

1

Differences among organisms are caused by...

Selecciona una de las siguientes respuestas posibles:

large differences in elemental composition from organism to organism.
differences in the types and relative amounts of organic molecules synthesized by each organism.
differences in the elements that bond with carbon in each organism.
differences in the sizes of the organic molecules in each organism.
differences in inorganic compounds present in each organism.

Explicación

Pregunta 64 de 94

1

A carbon atom is most likely to form what kind of bond(s) with other atoms?

Selecciona una de las siguientes respuestas posibles:

ionic
hydrogen
covalent
covalent bonds and hydrogen bonds
ionic bonds, covalent bonds, and hydrogen bonds

Explicación

Pregunta 65 de 94

1

Why are hydrocarbons insoluble in water?

Selecciona una de las siguientes respuestas posibles:

The majority of their bonds are polar covalent carbon-to-hydrogen linkages.
The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.
They are hydrophilic.
They exhibit considerable molecular complexity and diversity.
They are lighter than water.

Explicación

Pregunta 66 de 94

1

How many structural isomers are possible for a substance having the molecular formula C₄H₁₀?

Selecciona una de las siguientes respuestas posibles:

1
2
4
3
11

Explicación

Pregunta 67 de 94

1

Which of the following statements correctly describes cis-trans isomers?

Selecciona una de las siguientes respuestas posibles:

They have variations in arrangement around a double bond.
They have an asymmetric carbon that makes them mirror images.
They have the same chemical properties.
They have different molecular formulas.
Their atoms and bonds are arranged in different sequences.

Explicación

Pregunta 68 de 94

1

Research indicates that ibuprofen, a drug used to relieve inflammation and pain, is a mixture of two enantiomers; that is, molecules that

Selecciona una de las siguientes respuestas posibles:

have identical chemical formulas but differ in the branching of their carbon skeletons.
are mirror images of one another.
exist in either linear chain or ring forms.
differ in the location of their double bonds.

Explicación

Pregunta 69 de 94

1

A compound contains hydroxyl groups as its predominant functional group. Which of the following statements is true concerning this compound?

Selecciona una de las siguientes respuestas posibles:

It lacks an asymmetric carbon, and it is probably a fat or lipid.
It should dissolve in water.
It should dissolve in a nonpolar solvent.
It won't form hydrogen bonds with water.
It is hydrophobic.

Explicación

Pregunta 70 de 94

1

Which two functional groups are always found in amino acids?

Selecciona una o más de las siguientes respuestas posibles:

ketone
methyl
amino
carbonyl
carboxyl
hydroxyl
sulfhydryl

Explicación

Pregunta 71 de 94

1

Why are human sex hormones considered to be lipids?

Selecciona una de las siguientes respuestas posibles:

They are essential components of cell membranes.
They are not soluble in water.
They are made of fatty acids.
They are hydrophilic compounds.
They contribute to atherosclerosis.

Explicación

Pregunta 72 de 94

1

All of the following contain amino acids except...

Selecciona una de las siguientes respuestas posibles:

hemoglobin
cholesterol
abtibodies
enzymes
insulin

Explicación

Pregunta 73 de 94

1

Which of the following descriptions best fits the class of molecules known as nucleotides?

Selecciona una de las siguientes respuestas posibles:

A nitrogenous base and a phosphate group.
A nitrogenous base and a pentose sugar.
A nitrogenous base, a phosphate group, and a pentose sugar.
A phosphate group and an adenine or uracil.
A pentose sugar and a purine or pyrimidine.

Explicación

Pregunta 74 de 94

1

A primary objective of cell fractionation is to...

Selecciona una de las siguientes respuestas posibles:

view the structure of cell membranes.
sort cells based on their size and weight.
determine the size of various organelles.
separate the major organelles so that their particular functions can be determined.
separate lipid-soluble from water-soluble molecules.

Explicación

Pregunta 75 de 94

1

All of the following are part of a prokaryotic cell except...

Selecciona una de las siguientes respuestas posibles:

DNA
a cell wall
a plasma membrane
ribosomes
an endoplasmic reticulum

Explicación

Pregunta 76 de 94

1

Which of the following is a major cause of the size limits for certain types of cells?

Selecciona una de las siguientes respuestas posibles:

Limitation on the strength and integrity of the plasma membrane as cell size increases.
The difference in plasma membranes between prokaryotes and eukaryotes.
Evolutionary progression in cell size; more primitive cells have smaller sizes.
The need for a surface area of sufficient area to support the cell's metabolic needs.
Rigid cell walls that limit cell size expansion.

Explicación

Pregunta 77 de 94

1

Which organelle or structure is absent in plant cells?

Selecciona una de las siguientes respuestas posibles:

mitochondria
golgi vesicles
microtubules
centrosomes
peroxisomes

Explicación

Pregunta 78 de 94

1

Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules?

Selecciona una de las siguientes respuestas posibles:

lipids
glycogen
proteins
cellulose
nucleic acids

Explicación

Pregunta 79 de 94

1

Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large and complex lipids. Which cellular organelle must be involved in this condition?

Selecciona una de las siguientes respuestas posibles:

the endoplasmic reticulum
the Golgi apparatus
the lysosome
mitochondria
membrane-bound ribosomes

Explicación

Pregunta 80 de 94

1

Which organelle is the primary site of ATP synthesis in eukaryotic cells?

Selecciona una de las siguientes respuestas posibles:

lysosome
vacuole
mitochondrion
Golgi apparatus
peroxisome

Explicación

Pregunta 81 de 94

1

Which of the following is true for anabolic pathways?

Selecciona una de las siguientes respuestas posibles:

They do not depend on enzymes.
They are usually highly spontaneous chemical reactions.
They consume energy to build up polymers from monomers.
They release energy as they degrade polymers to monomers.

Explicación

Pregunta 82 de 94

1

Which of the following is the smallest closed system?

Selecciona una de las siguientes respuestas posibles:

a cell
an organism
an ecosystem
Earth
the universe

Explicación

Pregunta 83 de 94

1

Which of the following is true of metabolism in its entirety in all organisms?

Selecciona una de las siguientes respuestas posibles:

Metabolism depends on a constant supply of energy from food.
Metabolism depends on an organisms adequate hydration.
Metabolism uses all of an organism's resources.
Metabolism consists of all the energy transformation reactions in an organism.

Explicación

Pregunta 84 de 94

1

A chemical reaction that has a positive ΔG is correctly described as...

Selecciona una de las siguientes respuestas posibles:

endergonic
endothermic
exergonic
spontaneous

Explicación

Pregunta 85 de 94

1

Why is ATP an important molecule in metabolism?

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Its hydrolysis provides an input of free energy for exergonic reactions.
It provides energy coupling between exergonic and endergonic reactions.
Its terminal phosphate group contains a strong covalent bond that, when hydrolyzed, releases free energy.
Its terminal phosphate bond has higher energy than the other two.
It is one of the four building blocks for DNA synthesis.

Explicación

Pregunta 86 de 94

1

Which of the following statements is true concerning catabolic pathways?

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They combine molecules into more energy-rich molecules.
They supply energy, primarily in the form of ATP, for the cell's work.
They are endergonic.
They are spontaneous and do not need enzyme catalysis.

Explicación

Pregunta 87 de 94

1

When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated?

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It is used to power yet more cellular work.
It is used to store energy as more ATP.
It is used to generate ADP from nucleotide precursors.
It is lost to the environment.

Explicación

Pregunta 88 de 94

1

The active site of an enzyme is the region that

Selecciona una de las siguientes respuestas posibles:

binds allosteric regulators of the enzyme.
is involved in the catalytic reaction of the enzyme.
binds noncompetitive inhibitors of the enzyme.
is inhibited by the presence of a coenzyme or a cofactor.

Explicación

Pregunta 89 de 94

1

For the enzyme-catalyzed reaction shown in the figure, which of these treatments will cause the greatest increase in the rate of the reaction, if the initial reactant concentration is 1.0 micromolar?

Selecciona una de las siguientes respuestas posibles:

doubling the activation energy needed
cooling the reaction by 10°C
doubling the concentration of the reactants to 2.0 micromolar
doubling the enzyme concentration
increasing the concentration of reactants to 10.0 micromolar, while reducing the concentration of enzyme by 1/2

Explicación

Pregunta 90 de 94

1

This question is based on the reaction A + B ↔ C + D shown in the figure. Which of the following terms best describes the forward reaction in the figure?

Selecciona una de las siguientes respuestas posibles:

endergonic, ∆G > 0
exergonic, ∆G < 0
endergonic, ∆G < 0
exergonic, ∆G > 0
chemical equilibrium, ∆G = 0

Explicación

Pregunta 91 de 94

1

The oxygen consumed during cellular respiration is involved directly in which process or event?

Selecciona una de las siguientes respuestas posibles:

glycolysis
accepting electrons at the end of the electron transport chain
the citric acid cycle
the oxidation of pyruvate to acetyl CoA
the phosphorylation of ADP to form ATP

Explicación

Pregunta 92 de 94

1

Where are the proteins of the electron transport chain located?

Selecciona una de las siguientes respuestas posibles:

cytosol
mitochondrial outer membrane
mitochondrial inner membrane
mitochondrial intermembrane space
mitochondrial matrix

Explicación

Pregunta 93 de 94

1

In any ecosystem, terrestrial or aquatic, what group(s) is (are) always necessary?

Selecciona una de las siguientes respuestas posibles:

autotrophs and heterotrophs
producers and primary consumers
photosynthesizers
autotrophs
green plants

Explicación

Pregunta 94 de 94

1

In photosynthetic cells, synthesis of ATP by the chemiosmotic mechanism occurs during...

Selecciona una de las siguientes respuestas posibles:

photosynthesis only
respiration only
both photosynthesis and respiration
neither photosynthesis nor respiration

	Creado por Nicole Berozsky hace más de 9 años

Quiz questions to study for the final exam.

Biology 111

Pregunta 1 de 94

A cell has enough available ATP to meet its needs for about 30 seconds. What is likely to happen when an athlete exhausts his or her ATP supply?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 2 de 94

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 3 de 94

Cell membranes are asymmetrical. Which of the following statements is the most likely explanation for the membrane's asymmetrical nature?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 4 de 94

Fatty acids usually have an even number of carbons in their structures. They are catabolized by a process called beta-oxidation. The end products of the metabolic pathway are acetyl groups of acetyl CoA molecules. These acetyl groups ________.

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 5 de 94

If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence ______.

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 6 de 94

In solution, why do hydrolysis reactions occur more readily than condensation reactions?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 7 de 94

Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 8 de 94

Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this probably mean?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 9 de 94

The membranes of winter wheat are able to remain fluid when it is extremely cold by _____.

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 10 de 94

The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of ______.

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 11 de 94

Which of the following processes includes all others?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 12 de 94

Why is glycolysis considered to be one of the first metabolic pathways to have evolved?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 13 de 94

A localized group of organisms that belong to the same species is called a

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 14 de 94

Organisms interact with their environments, exchanging matter and energy. For example, plant chloroplasts convert the energy of sunlight into

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 15 de 94

The main source of energy for producers in an ecosystem is

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 16 de 94

Which of the following types of cells utilize deoxyribonucleic acid (DNA) as their genetic material but do not have their DNA encased within a nuclear envelope?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 17 de 94

To understand the chemical basis of inheritance, we must understand the molecular structure of DNA. This is an example of the application of which concept to the study of biology?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 18 de 94

Once labor begins in childbirth, contractions increase in intensity and frequency until delivery. The increasing labor contractions of childbirth are an example of which type of regulation?

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 19 de 94

Selecciona una de las siguientes respuestas posibles:

Explicación

Pregunta 20 de 94

The elongation of the leading strand during DNA replication

Selecciona una de las siguientes respuestas posibles:

Explicación