Bio 181 Final Exam
Which of the following is responsible for making every amino acid unique? a. Amino group b. Hydrogen c. Carboxyl group d. "R" group e. Carbon
"R" group
A patient is diagnosed with hypercortisolism. It is likely that this patient has an enlarged tissue that secretes __________. a.ADH b. Epinephrine c. adrenocorticotropic hormone (ACTH) d. Estrogen
adrenocorticotropic hormone (ACTH)
How many electrons are being shared during the formation of a single covalent bond?
2
Put the following steps of DNA replication in chronological order. 1. Single-stranded binding proteins attach to DNA strands. 2. Hydrogen bonds between base pairs of antiparallel strands are broken. 3. Primase binds to the site of origin. 4. DNA polymerase binds to the template strand. 5. An RNA primer is created.
2, 1, 3, 5, 4
What is the maximum number of single covalent bonds in which a carbon atom can participate?
4
As a result of the process of glycolysis, each molecule of glucose oxidized results in the formation of pyruvate and will produce (absolute number/not net gain)_____________. a. 2 molecules of ATP. b. 4 molecules of ATP. c. 6 molecules of ATP. d. 2 FADH2. e. no ATP is produced.
4 molecules of ATP
Within the nervous system, most of the cells communicate with each other via: a. None of the above b. gap junctions. c. Na+ exhange between cells. d. Chemical signals that spread across synapses. e. Direct electrical contact.
Chemical signals that spread across synapses.
When voltage-gated Ca(2+) channels at the axon terminal are activated by the spreading of an action potential, which of the following is observed at the neuromuscular junction? a. Release of Ca(2+) into the synaptic cleft. b. Transport of choline into the synaptic cleft. c. Fusion of vesicles containing acetylcholine at the axon terminal membrane to release neurotransmitter. d. The axon terminal membrane is depolarized. e. Ligand-gated sodium channels in the presynaptic neuron open.
Fusion of vesicles containing acetylcholine at the axon terminal membrane to release neurotransmitter.
This type of cell of the nervous system provides support to neurons, but itself does not have the capacity to conduct nerve impulses. a. Glial b. Neuron c. Dendrite d. Efferent e. Afferent
Glial
During the course of an animal experiment, a new molecule is discovered. After considering all the relevant evidence, it was determined that the molecule is a steroid hormone. Which of the following information led to this conclusion? I) the molecule is dissolved in lipid. II) the molecule is derived from cholesterol. III) the molecule exerts its effects on a tissue that is far from the tissue that is produced. IV) the molecule utilizes a protein to travel within an aqueous solution.
I, II, III, and IV
Indentify a location within the human body that the endocrine and nervous system work together to regulate physiological responses. a. Neurosecretory cells in the hypothalamus. b. The cells in the testes that produce testosterone. c. The cells in the adrenal gland that produce steroid hormones. d. Stimulation of the cortisol secretion by adrenocorticotropic hormone (ACTH). e. Neurons in the spinal cord.
Neurosecretory cells in the hypothalamus.
Which of the following glands if removed will most likely have the most wide-spread effects on human function of an adult ? a. Pancreas b. Ovaries (in female) or testes (in male) c. Andrenal gland d. Pituitary gland
Pituitary gland
Which of the following is responsible for maintaining the resting potential across the membrane of a neuron? a. Calcium pumps. b. Voltage-gated channels. c. Sodium-potassium pumps. d. Action potentials. e. Schwann cells.
Sodium-potassium pumps.
Researchers found E. coli that had mutation rates one hundred times higher than normal. Which of the following is the most likely cause of these results? a. The proofreading mechanism of DNA polymerase was not working properly. b. The DNA polymerase was unable to add bases to the 3' end of the growing nucleic acid chain. c. The single-stranded binding proteins were malfunctioning. d. There were one or more mismatches in the RNA primer.
The proofreading mechanism of DNA polymerase was not working properly.
bond interactions in increasing order of strengths
Van der waals hydrogen bonds ionic interactions covalent bonds
A series of hydrophobic side chains will congregate together as a protein folds in an aqueous solution and be stabilized by _____. a. hydrogen bonds b. quaternary structure bonds c. peptide bonds d. van der Waals interactions
Van der waals interactions
What part of the circulatory system in humans has the lowest blood pressure? a. Arterioles b. Left ventricle of the heart c. Vena cava d. Arteries e. Aorta
Vena cava
Archaeons and bacteria are a. very similar in appearance, but use a vastly different genetic code. b. are very different in appearance, being in two separate domains. c. are very different in appearance, the first have nuclei, the latter don't. d. very similar in appearance, being both prokaryotic.
Very similar in appearance, being both prokaryotic
Why does a starchy food, like bread, become hard and stale when it dries out? a. The release of carbon dioxide causes the bread to harden. b. When the bread dries out, seperate chains of starch are "glued" together through hydrogen bonds that form between them instead of the hydrogen bonds that formerly existed between them and (the now evaporated) water molecules. c. Water and heat cause the polysaccharide chains to bind together. d. Cellulose molecules aggregate in the absence of water. e. Mold growth interferes with α linkages, causing the bread to harden.
When the bread dries out, separate chains of starch are "glued" together through hydrogen bonds that form between them instead of the hydrogen bonds that formely existed between them and (the now evaporated) water molecules.
Choose the statement that is NOT TRUE with respect to heat exchange. a. When two objects that differ in temperature come in contact, heat is exhanged via conduction. b. None of the above c. An ectotherm or an endotherm can use mechanisms that involve changing the flow of the blood to the skin to regulate the exchange of heat between the body and the external environement. d. Wind can regulated the body temperature via the process of convection. e. When water evaporates from the skin the body gets warmer.
When water evaporates from the skin the body gets warmer.
Most of the gas exchange between the air and the blood in the lungs of mammals takes place in the _____. a. bronchi b. larynx c. bronchioles d. alveoli e. trachea
alveoli
During the fight-or-flight response there is activation of the ______________. a. posterior pituitary gland, to increase oxytocin. b. thyroid gland, to stimulate an increase in metabolism. c. pancreas, to decrease the blood glucose concentration. d. adrenal medulla, to increase blood epinephrine concentration. e. anterior pituitary gland, to stimulate the gonads to secreate FSH.
anterior pituitary gland, to stimulate the gonads to secreate FSH.
Transcription of eukaryotic genes requires ____. (more than one) capping of mRNA. binding of RNA polymerase to the promoter. polyadenylation binding of several transcription factors.
binding of RNA polymerase to the promoter. binding of several transcription factors.
Bacteria belonging to the species Microcosmos universalis have flagella. A mutant strain of the bacteria, though, lack flagella. Compared to cells of the wildtype ("normal") strain, mutant cells a. cannot swim. b. have a very different overall shape. c. will dry out. d. lost their ability to adhere to other cells. e. can no longer regulate the movement of molecules into and out of the cell.
cannot swim
The largest amount of carbon dioxide generated in human metabolism is _____. a. bound to hemoglobin b. bicarbonate ions bound to hemoglobin c. transported in the red blood cells d. found dissolved in plasma e. converted to bicarbonate ions
converted to bicarbonate ions
When the body responds to stress, glucose is produced in the liver via the process of gluconeogenesis. This process is mediated by the hormone ____________ produced in the andrenal glands. a. follicle-stimulating hormone b. adrenocorticotropic (ACTH) c. luteinizing hormone d. epinephrine e. cortisol
cortisol
Griffith's studies of Streptococcus pneumoniae (also called pneumococcus in the medical jargon) _______. a. proved that protein is not the genetic material. b. showed that DNA is the genetic material of bacteria. c. demonstrated the phenomenon of bacterial transformation. d. proved that prokaryotes reproduce sexually. e. showed that DNA is the genetic material of bacteriophage.
demonstrated the phenomenon of bacterial transformation
Evidence of the semiconservative nature of DNA replication came from a. DNA staining techniques. b. DNA sequencing. c. density gradient studies using DNA labeled with a heavy isotope of nitrogen. d. X-ray crystallography. e. None of these
density gradient studies using DNA labeled with a heavy isotope of nitrogen.
Energy in acetyl CoA, used to support reactions in the citric acid cycle,_____________________________________. a. generates directly ATP. b. reduces FAD to FADH2. c. creates an H+ gradient. d. reduces NAD+ to NADH. e. drives the oxaloacetate to form citrate.
drives the oxaloacetate to form citrate.
When typing a text on your smart device, the central nervous system directs your fingers by sending commands that are carried by_________________. a. afferent neurons. b. efferent neurons. c. schwann cells. d. glial cells. e. None of the above
efferent neurons.
The amino acids of the protein keratin are arranged in an α-helix. This secondary structure is stabilized by a. polar bonds. b. hydrogen bonds. c. covalent bonds. d. peptide bonds. e. glycosidic linkages.
hydrogen bonds
The force of _______ holds DNA together in a double helix. a. the twist b. hydrogen bonds c. ionic bonds d. ionic interactions e. covalent bonds
hydrogen bonds
A general function of the glucocorticoids is to ____________________. a. build up muscle proteins b. increase glucagon production. c. increase the blood glucose concentration d. activate the immune system
increase the blood glucose concentration
You have a drug that you know that it increases the synthesis of adrenocorticotropic hormone (ACTH). Which of the following would be an effect of that drug? a. increased release of corticotropin-releasing hormone (CRH) b. increased production of glucocorticoid c. decreased release of cortisol d. decreased release of corticotropin-releasing hormone (CRH)
increased production of glucocorticoid
The DNA of mitochondria a. is similar in organization, but not in complexity, to that of the nuclear DNA. b. is derived from nuclear DNA in which the telomeres were joined together to make a ciruclar molecule. c. is organized as linear chromosomes. d. is an evolutionary relic, carrying very few genes that are, nonetheless, absolutely essential for cellular respiration is translated directly by ribosomes (without the need for the intermediary functions of RNA).
is an evolutionary relic, carrying very few genes that are, nonetheless, absolutely essential for cellular respiration is translated directly by ribosomes (without the need for the intermediary functions of RNA).
This leads you to conclude that the effect on molecule PAARF 23 _________________________. a. is not mediated by nerves b. is controlled by higher brain centers c. is not mediated by hormones d. during the first experiment was just an error
is not mediated by hormones
Starch and glycogen are different in that only one of them a. is a polymer of hexose sugars. b. contains glucose residues linked through α-glycosidic linkages c. none of the answers points to a difference. d. is an energy storage molecule. e. can be digested by humans. f. all of the answers point to a difference.
none of the answers points to a difference
In prokaryotes, initiation of translation involves: a. positioning of the preinitiation complex near the initiation codon via base-pairing between mRNA and the 16S rRNA. b. preinitiation complex formation at the mRNA's 5'-cap. c. scanning of the preinitiation complex along the mRNA to locate the initiation codon. d. assembly of the preinitiation complex with the 50S ribosome subunit bound to mRNA, followed by binding of 30S ribosome subunit. e. positioning of the preinitiation complex near the initiation codon via binding of IF4 to IF1.
positioning of the preinitiation complex near the initiation codon via base-pairing between mRNA and the 16S rRNA.
The three basic parts of an operon are the a. promoter, the operator, and two or more structural genes. b. structural genes, the mRNA, and the tRNAs. c. promoter, the structural genes, and the termination codons. d. None of the above e. promoter, the mRNA, and the termination codons.
promoter, the operator and two or more structural genes
In mitochondria, exergonic reduction-oxidation reactions __________. a. provide the energy driving the first steps of glycolysis. b. are coupled via phosphorylation to endergonic processes c. provide the energy for substrate-associated phosphorylation d. provide the energy that builds up a proton gradient e. reduce carbon atoms to CO2
provide the energy that builds up a proton gradient
The genetic code is best described as ____. a. redundant but not ambiguous. b. ambiguous but not redundant. c. nonsense. d. both ambiguous and redundant. e. neither ambiguous nor redundant.
redundant but not ambiguous.
What provides the energy for the polymerization reactions in DNA synthesis? a. ATP b. DNA polymerase c. breaking the hydrogen bonds between complementary DNA strands d. the deoxyribonucleotide triphosphate substrates
the deoxyribonucleotide triphosphate substrates
How does air move into the lungs of humans during inhalation? a. muscles in the lung contract and pull air in. b. in a passive fashion along the respiratory tree. c. by creating positive pressure as a result of the contractin of the diaphragm. d. the diaphragm contracts and increases the lung volume. e. the volume of the alveoli increases.
the diaphragm contracts and increases the lung volume.
A molecule of CO2 is released into the blood from your big toe of your right foot and is ultimately exhaled from your nose. All of the following describe a location in the path of the molecule, EXCEPT_____________. a. the pulmonary vein b. the right ventricle c. an alveolus d. the trachea e. the right atrium
the pulmonary vein
You are told that when ATP is hydrolyzed there is generation of ATP, ADP, Pi, and energy (~7.3 kcal/mol). Based on this information you determine that: a. the reaction does not release free energy. b. the reaction requires energy. c. the reaction is exergonic. d. the reaction is endergonic. e. the reaction cannot be reversed.
the reaction is exergonic.
The proton gradient in the mitochondria is maintained by___________________________. a. Complex V, known also as ATP synthase. b. transporting electrons and pumping protons. c. breaking down water. d. ATP production in the citric acid cycle. e. oxidizing pyruvate to lactic acid.
transporting electrons and pumping protons.
A person drinking alcohol shows increased frequency in using the restrooms to urinate. This is in line with a change in the levels of the antidiuretic hormone (ADH) in this person. Which of the following might explain the increased frequency in urination? a. Alcohol inhibits the secretion of ADH. b. Alcohol down-regulated the ADH receptors in the kidneys. c. Alcohol inhibits the interaction of ADH with its receptors in the kidneys. d. Alcohol stimulates the secretion of ADH.
Alcohol inhibits the secretion of ADH.
Countercurrent heat exchange is associated with: a. greater ability to generate mechanical power. the evolution of fish b. movement of warm blood from the muscles next to cold blood traveling towards the muscles. c. All of the above d. Helping the fish to maintain a body temperature that is higher than the temperature in its enviroment.
All of the above
Which of the following would be an example of potential energy? a. Both: chemical bonds in fatty acid AND concentration gradient b. All of the above c. Chemical bonds in fatty acid d. Concentration gradient e. Imbalance in electrical charges of molecules
All of the above
Which of the following characteristics or features can provide an advantage for an endotherm when the enviromental temperature is low and it wants to maintain body temperature? a. Two of the answers are correct b. Active decrease in the body surface area. c. All of the answers are correct d. Decrease in blood flow to the skin. e. Shivering.
All of the answers are correct
A cell _____ a. all of the statements, including this one, are correct. b. is the fundamental component of all organisms including plants and animal. c. may be a distinct entity or a building block of a more complex organism, including multicellular organisms and unicellular organisms that cooperate as a colony. d. may be a constituent of a "tissue". e. can be studied intact, or broken up into its subcellular constituents and studied in vitro (literally, "within glass", or in a test tube)
All of the statements are correct
If 15 percent of the bases in a sample of single-stranded DNA is adenine, what percentage of the bases would be cytosine? a. 70 b. 30 c. 40 d. Because the DNA is single-stranded the Chargaff's rule doesn't apply and there's no way to know. e. 15 f. 35
Because the DNA is single stranded the Chargaff's rule doesn't apply and there's no way to know.
Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly? a. glucose b. K+ c. CO2 d. an amino acid e. starch
CO2
Which of the following statements about the nervous system is FALSE? a. It is composed of central nervous systems and peripheral nervous system. b. Choline covers the axons of neurons in the peripheral nervous system. c. Effectors include muscles or glands. d. Summation of postsynaptic potential is a way to make a neuron to reach a threshold and fire an action potential. e. Can observe both excitatory and inhibitory postsynaptic potentials.
Choline covers the axons of neurons in the peripheral nervous system.
An otherwise healthy person develops a condition that increases the amount of interstitial fluid around the capillaries sourounding the lungs. What do you expect to happen when this condition develops? a. Decrease in the amount of O2 diffusing from the lungs into the blood. b. Increase in the amount of O2 diffusing from the lungs into the blood. c. Decrease in the amount of work that his inspiratory muscles have to do to achieve effective ventilation. d. Increase in the amount of carbon dioxide diffusing from the blood to the lungs. e. Increase in pressure within the capillaries, causing the capillaries to burst.
Decrease in the amount of O2 diffusing from the lungs into the blood.
John has lived all his life by the water (sea level). Which of the following would John likely experience if he was suddenly flown by helicopter on a nearby mountain of very high altitude where the atmospheric pressure is much much lower than that observed at sea level? a. He will experience increased blood flow to the brain. b. He will decrease his ventilation. c. He will experience a large increase in his blood pH. d. He will have trouble breathing.
He will have trouble breathing
It is known that hemogolbin acts as a buffer to protect from changes in blood pH. What is the mechanism? a. Hemoglobin can bind excess protons released by the metabolism of carbonic acid. b. Hemoglobin generates protons that can alter the blood pH. c. Any binding of oxygen in hemoglobin is reduced drastically after the first proton interacts with hemoglobin. d. Hemoglobin can bind protons generated in the red blood cells in a way that their subsequent metabolism leads to increased excretion of protons through the kidneys.
Hemoglobin can bind excess protons released by the metabolism of carbonic acid.
Why do histones bind tightly to DNA? a. Histones are positively charged, and DNA is negatively charged. b. Both histones and DNA are strongly hydrophobic. c. Histones are covalently linked to the DNA. d. Histones are negatively charged, and DNA is positively charged. e. Histones are highly hydrophobic, and DNA is hydrophilic.
Histones are positively charged, and DNA is negatively charged.
Succesful inhibition of acetylcholinesterase by a drug in the neuromuscular junction will result in which of the following? a. Inhibition of the breakdown of neurotransmitter within the synapse. b. Inhibition of the release of neurotransmitter from the presynaptic neuron. c. Inhibition of Ca(2+) uptake within the axon terminal d. Inhibition of the activation of the Na+ channels in the postsynaptic membrane. e. Inhibition of the synthesis of neurotransmitter within the neuron.
Inhibition of the breakdown of neurotransmitter within the synapse.
Which of the following best describes estrogen? a. It is a hormone derived from amino acid. b. It is a polypeptide hormone. c. It is a lipid-soluble hormone. d. It is a neurotransmitter. e. It is made by the andrenal cortex.
It is a lipid-soluble hormone.
Chose the statement that is false when describing a positive feedback. a. It is the most common feedback mechanism in life. b. It will continue in a way that reaches a limit and then quickly stops. c. It increases the magnitude of the observed response. d. Opening of adjacent sodium channels during propagation of the signal along the axis of a neuron is an example.
It is the most common feedback mechanism in life.
How would you describe the process of ventilation? a. It is the movement of CO2 through the circulatory system. b. It is the movement of O2 within the circulatory system c. It is the movement of water or air past a respiratory surface. d. It is the diffusion of gases in and out of the blood. e. Is it the diffusion of oxygen and carbon dioxide into and out of the cell.
It is the movement of water or air past a respiratory surface.
Brown fat has various functions in biology. Which of the following is NOT TRUE about brown fat? a. It provides energy associated with shivering. b. Glucose can be utilized in this tissue without producing ATP. c. It has a lot of mitochondria. d. It is commontly found in hibernating animals.
It provides energy associated with shivering.
Which of the following correctly describes the role of epinephrine during the fight-or-flight response? a. It increases the end-diastolic volume in the heart. b. It supresses glucose utilization in the muscle. c. It works in parallel with cortisol to make sure there is sufficient sugar in the blood. d. It is a steroid hormone. e. It is produced by the action of corticotropin-realizing hormone (CRH).
It works in parallel with cortisol to make sure there is sufficient sugar in the blood.
Agrobacterium infects plants and causes them to form tumors. You are asked to determine how long a plant must be exposed to these bacteria to become infected. Which of the following experiments will provide the best data to address that question? a. Measure the number of tumors formed on a plant when exposed to various concentrations of Agrobacterium. b. Measure the number of tumors formed on plants, which are exposed to Agrobacterium for different lengths of time. c. Measure the concentration of Agrobacterium in different soil environments where the plants grow. d. Determine the survival rate of Agrobacterium when exposed to different concentrations of an antibiotic.
Measure the number of tumors formed on plants, which are exposed to Agrobacterium for different lengths of time.
When oxygen is not present, utilization of glucose through glycolysis can continue because of the formation of lactic acid. What is happening during the metabolic process that reduces pyruvate to lactic acid? a. ATP is synthesized via the proton gradient. b. Water is formed. c. FADH2 is oxidized to FAD+ d. A phospate group is transfered to ADP. e. NADH is oxidized to NAD+
NADH is oxidized to NAD+
The end-point oxidizing agent within the mitochondria and electron transport chain is: a. O2. b. NAD+. c. ATP. d. FAD. e. ubiquinone.
O2
Which of the following statements regarding the amino acid glycine is false? a. The side chain of glycine is uncharged throughout the pH scale. b. Only the L optical isomer of glycine is found in proteins. c. Glycine has the a hydrogen atom for a side chain. d. Its side chain is small enough to allow glycine to fit into tight corners of protein molecules.
Only the L optical isomer of glycine is found in proteins
How can the leading and lagging strands be synthesized in a coordinated fashion? a. The lagging strand is extended in the 3´-to-5´ direction and the leading strand is extended in the 5´-to-3´ direction. b. Pol III is a dimeric holoenzyme, and the looped lagging strand allows the enzyme to proceed in the same direction with each strand. c. Lagging-strand binding proteins inhibit leading-strand replication if the strands become disproportionate in size. d. Specific enzymes control the size of the DNA opening.
Pol III is a dimeric holoenzyme, and the looped lagging strand allows the enzyme to proceed in the same direction with each strand.
What is a major difference between eukaryotic DNA replication and prokaryotic DNA replication? a. Prokaryotic replication does not require a primer. b. Prokaryotic chromosomes have a single origin of replication, while eukaryotic chromosomes have multiple origins of replication. c. DNA polymerases of prokaryotes can add nucleotides to both 3' and 5' ends of DNA strands, while those of eukaryotes function only in the 5' → 3' direction. d. DNA replication in prokaryotic cells is conservative. DNA replication in eukaryotic cells is semi-conservative.
Prokaryotic chromosomes have a single origin of replication, while eukaryotic chromosomes have multiple origins of replication.
Which of the following processes takes place within the electron transport chain of the mitochondria? a. All of the above b. CO2 is reduced. c. None of the above d. Protein complexes, FADH, and NADH are oxidized e. CO2 is produced.
Protein complexes, FADH, and NADH are oxidized
which has the lowest surface to volume ratio (surface area/volume)? a. Red blood cells b. E. coli c. influenza virus d. All presented entities have similar surface area to volume ratios.
Red blood cells
A person starts running up towards the top of a hill and is expected to take him at least three minutes to reach the top. What do you expect to happen to his ability to reach the top if signals from neurons and the medulla that are responsible to detect changes in blood pH are blocked? a. She/he will have easier time reaching the top because blood pH will increase. b. She/he will have harder time reaching the top because his ventilation will not increase sufficiently to effectively diffuse more oxygen to the blood. c. She/he will have easier time reaching the top because oxygen diffusion from alveoli towards blood will increase to allow more oxygen to bind to the hemoglobin. d. She/he will have harder time reaching the top because oxygen diffusion from alveoli towards blood will increase, but no more oxygen can bind to hemoglobin. e. She/he will not have harder time reaching the top because blocking these signals will not have any physiological effect in his effort to reach the top of the hill.
She/he will have harder time reaching the top because his ventilation will not increase sufficiently to effectively diffuse more oxygen to the blood.
All of the following are behaviors that a lizard uses to thermoregulate, except: a. Basking in the sun early in the morning b. Moving under a shade in the middle of a sunny day in the desert c. Pressing its body against cooler rock during the middle of a sunny day in the desert d. Staying in a burrow when the surface temperature is below 10°C e. Shivering
Shivering
What is some of the evidence in favor of the notion that the peptide bond has the charactaristics of a double bond?
Six atoms about the peptide bond lie in the same plane: the α-carbon atom and C=O group of the first residue and the NH group and α-carbon atom of the second residue. Rotation about the bond between the C=O group of the first residue and the NH group of the second residue is prevented.
What is/are the primary regulator(s) of breathing in mammals? a. The hemoglobin in the blood. b. The lungs. c. The concentration of albumin in the blood. d. The red blood cells and hemoglobin concentation in the blood. e. The CO2 and pH in the blood.
The CO2 and pH in the blood.
What do you expect to happen if there is large increase in the albumin concentration in the plasma of a human because of disease state? a. Changes in protein concentration have nothing to do with changes in fluid volumes. b. The blood volume will decrease while that of lymph will increase. c. The blood volume and lymph volume will both decrease. d. The blood volume will increase while that of lymph will decrease. e. The blood volume and lymph volume will both increase.
The blood volume will increase while that of lymph will decrease.
You have a circumstance that the cortisol receptors in the hypothalamus of an individual are not functioning. What would the most likely observation be in this individual during times that the individual is exposed to increased stress? a. The individual's blood glucose concentration would decrease way below normal levels. b. The individual would not produce ACTH. c. The individual's blood glucose concentration would increase way above normal levels. d. The individual would not produce CRH. e.The individual would not proceduce cortisol.
The individual's blood glucose concentration would increase way above normal levels.
According to the lac operon model proposed by Jacob and Monod, what is predicted to occur if the operator is removed from the operon? a. Galactosidase permease would be produced, but would be incapable of transporting lactose. b. Only lacY would be transcribed. c. Only lacZ would be transcribed. d. The lac operon would be transcribed continuously.
The lac operon would be transcribed continuously.
You have just discovered an organism that lives in extremely cold environments. Which of the following would you predict to be true about the phospholipids in its membranes, compared to phospholipids in the membranes of organisms that live in warmer environments? a. The membrane phospholipids of cold-adapted organisms will have longer hydrocarbon tails. b. The membrane phospholipids of cold-adapted organisms will have more unsaturated hydrocarbon tails. c. The membrane phospholipids of cold-adapted organisms will have more saturated hydrocarbon tails.
The membrane phospholipids of cold-adapted organisms will have more unsaturated hydrocarbon tails.
What properties of water are important for biological processes?
The polarity of water, the cohesive properties of water, and its high specific heat (in comparison to other small molecule liquids)
As the partial pressure of oxygen increases, the oxygen content of water increases in linear fashion. However, with an increase in oxygen partial pressure, the oxygen content of blood increases in a sigmoidal fashion. What is the explanation? a. the presence of hemoglobin b. the Bohr effect c. the enzyme called carbonic anhydrase being present in the blood but not in water. d. What is described in the question/statement cannot happen.
The presence of hemoglobin
Oxygen cannot be stored in the body tissues, but if we measure the oxygen content in muscle will realize that it is found in greater amounts than it can be explained by the diffusion of oxygen across tissues. What is the explaination. a. Oxygen is stored in the matrix of mitochondria in specialized vesicles called hemoglobin-vesicles. b. The presence of hemoglobin c. The enzyme carbonic anhydrase is really active in muscle producing oxygen-containing molecules d. The presence of myoglobin e. There is great accumulation of biocarbonate ions (HCO3-) in muscle that oxygen is associated with.
The presence of myoglobin
Recent studies have shown that xeroderma pigmentosum (an error in the nucleotide excision repair process) can result from mutations in one of seven genes. What can you infer from this finding? a. These mutations have resulted from translocation of gene segments. b. There are seven genes that produce the same protein. c. There are several proteins involved in the nucleotide excision repair process. d. These seven genes are the most easily damaged by ultraviolet light.
There are several proteins involved in the nucleotide excision repair process.
Which of the following statements regarding the diseases Kuru and bovine spongiform encephalopathy (mad cow disease) are correct?
These diseases involve an infectious protein. The causal agent, prion, assumes a pathological beta sheet conformation instead of the normal alpha helical structure.
The envelopes surrounding nuclei, mitochondria and chloroplasts have which of the following characteristics in common? a. They are highly leaky when ions are concerned b. They are composed almost entirely of hydrophobic proteins. c. They are composed of two membrane bilayers. d. They are continuous with the plasma membrane. e. They interact with ribosomes during translation.
They are composed of two membranes
Which of the following statements about TATA boxes is false? a. They help specify the starting point for transcription. b. They bind a specific transcription factor. c. They contain thymine-adenine base pairs. d. They are part of the intron consensus sequence. e. They are found in the region of the promoter.
They are part of the intron consensus sequence.
Which of the following is true with respect to action potentials. a. They are the result of opening of Na+ gated channels in the cell membrane. b. They will be initiated by increase permeability of the cell membrane to chloride. c. They will be initiated by increased permeability of the cell membrane to potassium. d. They will be initiated by increase permeability of the cell membrane to calcium. e. They will fade-out following the opening of Na+ channels.
They are the result of opening of Na+ gated channels in the cell membrane.
Which of the following is TRUE with respect to action potentials. a. They move less fast in the case of myelinated nerve cells. b. They move along the axon of a neuron at a constant speed. c. They cause a brief depolarization of the membrane. d. The nodes of Ranvier block the generation of action potentials. e. They are observed as single action potential along the entire axon of a neuron.
They cause a brief depolarization of the membrane.
With respect to neurons, which of the following statements is TRUE? a. They fire or not action potentials only based on the number and size of the excitatory inputs they receive. b. They fire or not action potentials based on the sum of excitatory and inhibitory postsynaptic potentials. c. The speed of conduction cannot be altered in a neuron from birth to old age. d. None is true. e. The decision whether to fire or not an action potential is made in the dendrites.
They fire or not action potentials based on the sum of excitatory and inhibitory postsynaptic potentials.
Of the following, which is the most current description of a gene? a. a DNA sequence that is expressed to form a functional product: either RNA or polypeptide b. a DNA subunit that codes for a single complete protein c. a DNA RNA sequence combination that results in an enzymatic product d. a unit of heredity that causes formation of a phenotypic characteristic e. a discrete unit of hereditary information that consists of a sequence of amino acids
a DNA sequence that is expressed to form a functional product: either RNA or polypeptide
During exhalation, movement of air from the lungs in humans is the result of _________. a. an expansion of the thoracic volume. b. enlargment of the trachea c. a decrease in the residual volume in the lungs d. the contraction of the diaphragm e. a decrease in the thoracic volume
a decrease in the thoracic volume
The partial negative charge at one end of a water molecule is attracted to the partial positive charge of another water molecule. What is this attraction called? a. a hydrophilic bond b. an ionic bond c. a van der Waals interaction d. a hydrogen bond e. a covalent bond
a hydrogen bond
The CAP protein (also known as CRP) can A. prevent expression of the lac operon when cAMP levels are low by binding to the promoter (thus blocking it), but when cAMP levels are high, it is released from the promoter and allows the RNA polymerase to bind and start transcription. B. activate the lac operon by binding to the promoter when cAMP levels are high, but prevent expression of the operon when cAMP levels are low by binding to the operator (thus blocking the polymerase). C. activate expression of the lac operon by binding to the promoter and to the RNA polymerase when cAMP levels are high. D. activate expression of the lac operon by binding to the 5 -methyl cap of the lac mRNA when cAMP levels are high.
activate expression of the lac operon by binding to the promoter and to the RNA polymerase when cAMP levels are high.
Spontaneous generation _____ a.occurs every time a new species evolves from a preexisting species b. was demonstrated to occur under normal laboratory conditions by Pasteur c. addresses the formation of new cells from existing cells d. apparently occurred at least once when life on Earth emerged.
apparently occurred at least once when life on Earth emerged
The structural genes present in an operon A. Are cleaved to individual mRNA each coding for one protein B. are transcribed individually as separate mRNAs when an operator is turned on. C. are transcribed individually depending on whether a regulator molecule is bound at the operator site for each gene. D. are all co-transcribed as a single mRNA when the operon is turned on.
are all co-transcribed as a single mRNA when the operon is turned on.
Which of the following amino acids have very similar side chains with extremely similar chemical properties? (more than 1) glutamine serine aspartate glutamate glycine
aspartate, glutamate
DNA polymerase lengthens a polynucleotide strand by a. adding lost DNA sequences to the 3´ end. b. threading the existing DNA through a replication complex. c. building short DNA fragments and linking them together. d. covalently linking new nucleotides to a previously existing strand. e. linking purines with pyrimidines.
covalently linking new nucleotides to a previously existing strand.
The goal of moving hydrogen ions from the matrix to the intermembrane space is to ______________. a. reduce NAD+. b. synthesize ATP. c. restore the balance of Na+ and K+ ions across the mithochondrial membrane. d. create of a proton gradient. e. oxidize glucose to form lactate
create of a proton gradient.
The chemiosmotic theory states that the energy utilized for the synthesis of ATP in the mitochondria is provided directly by the ______________. a. reduction of FADH2. b. breakdown of GTP. c. reduction of NAD+. d. diffusion of protons. e. breakdown of other ATP molecules.
diffusion of protons
Based on the "chemiosmotic" hypothesis, energy for the synthesis of ATP in the mitochondria is provided via: a. hydrolysis of ATP to ADP. b. hydrolysis of GTP to GDP. c. diffusion of protons. d. reduction of NAD+. e. reduction of FAD.
diffusion of protons.
Hypothalamus has a central role in determining thermoregulatory responses in the body. Which of the following would be a response of the hypothalamus to an increase in internal temperature? a. Initiation of shivering in muscles b. Increase the heat production in the muscles c. Reset its thermostat to a higher temperature d. Inhibition of neuronal sensory response e. Dilation of vessels delivering blood to the skin
dilation of vessels delivering blood to the skin
The least amounts of carbon dioxide produced the citric acid cycle in cells is found within the blood in humans ______________________________. a. dissolved in plasma. b. within bicarbonate ions that are bound to hemoglobin. c. bound to hemoglobin. d. within bicarbonate ions circulating in plasma. e. in red blood cells.
dissolved in plasma
What type of covalent bonds between amino acid side chains (R-groups) functions in maintaining a polypeptide's specific three-dimensional shape? a. hydrophobic interactions b. hydrogen bonds c. van der Waals interactions d. ionic bond e. disulfide bonds
disulfide bonds
A DNA sequence, which can be distant from the gene, stimulates transcription when bound by a protein. This sequence is called a(n) a. promoter. b. operon. c. TATA box. d. enhancer. e. consensus sequence.
enhancer
The guanosine triphosphate (GTP) cap that is added to the 5' end of primary mRNA a. facilitates the binding of mRNA to ribosomes. b. provides the mRNA molecule with a poly A tail. c. contains all the coding and noncoding sequences of the DNA template. d. helps transfer amino acids to the ribosomes. e. is linked to the first transcribed base via hydrogen bonds.
facilitates the binding of mRNA to ribosomes.
You are driving in a country road at 70 mph when the speed limit is 60 mph. A driver going the opposite direction signals that there is a police car on the side of the road in the direction you are going. That other driver is providing. a. an error signal. b. a set point modification c. positive feedback. d. feedforward information. e. no information
feedforward information.
Which of the following will an atmospheric molecule of oxygen need to cross to ultimately bind to the hemoglobin in mammals? a. two membranes related to the in and out of the cell lining the lung, and then bind directly to hemoglobin b. one membrane, which forms the lining in the lungs, and then bind directly to hemoglobin c. five membranes: in and out of the cell lining the lung, in and out of the endothelial cell lining an alveolar capillary, and into the red blood cell that contains the hemoglobin d. four membranes: in and out of the cell lining the lung, in and out of the endothelial cell lining an alveolar capillary, and then bind directly to hemoglobin e. zero membranes because oxygen binds directly to hemoglobin
five membranes: in and out of the cell lining the lung, in and out of the endothelial cell lining an alveolar capillary, and into the red blood cell that contains the hemoglobin
Where is countercurrent exchange evident with respect to the flow of blood and material that contains oxygen? a. insects b. trachea of birds c. gills of fish d. lungs of humans
gills of fish
When considering the overall reaction of glucose metabolism resulting in complete oxidation of the molecule (shown below), which is a correct statement? C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy a. glucose is oxidized and oxygen is reduced. b. None of the statements is correct c. oxygen and carbon dioxide are both oxidized d. oxgyen and carbon dioxide are both reduced e. oxygen is oxidized and water is reduced.
glucose is oxidized and oxygen is reduced.
The first step of glucose metabolism in the cells is? a. GTP formation. b. the citric acid cycle. c. pyruvate oxidation to Acetyl-CoA. d. glycolysis. e. lactic acid production.
glycolysis
Some species sometimes regulate their body temperature on their own and sometimes their body temperature is determined directly by the enviroment that they are in. These species are called ___________. a. endotherms. b. ectotherms. c. heterotherms. d. There are no such species e. alternative species.
heterotherms
The hormones stored and ultimately secreted by the posterior pituitary gland are produced within the ___________. a. anterior pituitary gland b. central nervous system c. hypothalamus d. andrenal medulla e. posterior pituitary gland
hypothalamus
The smooth ER ________. a. is connected to the Golgi apparatus. b. is the site of steroid synthesis. c. was the name of a long-running TV series starring George Clooney. d. has ribosomes attached to its membrane. e. is an internal membrane system found within the rough ER and resembling the thylakoid membranes of chloroplasts. f. is where proteins such as insulin start their journey through the secretory pathway.
is the site of steroid synthesis
The upper limit in temperature within the cells is important because: a. it determines if proteins/enzymes are intact and functional. b. it increases protein utilization for energy. c. it promotes the utilization of fat compared to glucose for energy. d. it can regulate sweating. e. it can keep the cell warm.
it determines if proteins/enzymes are intact and functional.
A person walking across the dessert in the middle of the day loses large amounts of water and she/he is at risk of dying from dehydration. In this circumstance, the antidiuretic hormone (ADH) targets cells within the ___________________ to prevent excessive water loss. a. adrenal gland b. bladder c. kidney d. anterior pituitary gland e. posterior pituitary gland
kidney
One of the roles of the proteins found within plasma in humans is to __________. a. carry out gas exchange b. transport lipids c. regulate the aerobic metabolism d. transport oxygen e. maintain the blood's osmotic pressure
maintain the blood's osmotic pressure
One way to figure out whether the endocrine system is responsible for a specific physiological effect is to cut the neurons to the tissue of the animal where the effect is observed. The purpose of this is to _______________________________. a. make sure that the organ that the effect is observed cannot function unless it is stimulated with an external electrical probe. b. numb that tissue so it is not cause any pain to the animal c. make sure that the effect does not happen via the effects of the nervous system. d. impair the normal function of the tissue so that the hormone produced by that tissue can be measured mroe precisely
make sure that the effect does not happen via the effects of the nervous system.
What is the purpose of countercurrent exchange in the gills of fish? a. lose body heat more effectively b. maximize swimming efficiency c. increase gas balance d. maximize gas diffusion e. retain body heat
maximize gas diffusion
What term is used to describe the sum of the overall chemical reactions that take place within a living organism? a. catabolism. b. bioenergetics. c. metabolism. d. biochemistry. e. anabolism.
metabolism.
What is the correct ordering by the levels of complexity at which life is studied, from most simple to most complex?
molecule cell tissue organ organism population biosphere
During the formation of a peptide linkage, a (an) _______ is formed. a. disulfide bridge b. ionic bond c. hydrophilic bond d. hydrophobic bond e. molecule of water
molecule of water
Which of the following characteristic will provide for the fastest transmision of action potentials along the nerve axon? a. characteristic that is specific to vertebrate type of nerve. b. characteristic that is specific to invertebrate type of nerve. c. myelin sheath. d. having a lot of ion channels on the plasma membrane. e. small axon diameter.
myelin sheath
Which of these provides evidence of the common ancestry of all life? a. ubiquitous use of catalysts by living systems b. structure of chloroplasts c. structure of the nucleus d. structure of cilia e. near universality of the genetic code
near universality of the genetic code
You decide to hold your breath for 40 seconds. Which of the following will have its partial pressure decrease within the lungs over those 40 seconds? a. none of the above is correct b. both carbon dioxide and oxygen c. carbon dioxide only d. oxygen only
oxygen only
Which of the following hormones is paired correctly with its action? a.Epinephrine-stimulates vasodilation in the gut. b. adrenocorticotropic hormone (ACTH)-stimulates glucose utilization. c. Epinephrine-inhibits vasodilation in the muscle. d. oxytocin-stimulates uterine contractions during childbirth Antidiuretic hormone (ADH)- increases the absorption of sodium in the blood.
oxytocin-stimulates uterine contractions during childbirth
The Bohr shift on the oxygen-hemoglobin dissociation curve is produced by changes in _____. a. the partial pressure of oxygen b. hemoglobin concentration c. pH d. the partial pressure of carbon monoxide e. temperature
pH
The backbones of DNA and RNA consist of a. hexoses. b. maltoses. c. pentoses. d. amyloses. e. fructoses.
pentoses
The linkage between adjacent nucleotides in a nucleic acid chain is called a. disulfide bond. b. amide bond. c. phophodiester bond. d. glycosidic bond e. peptide bond
phophodiester bond
Although ATP is largely produced via the activation of complex V in the mitochondria, cells can also generate ATP through substrate-level phosphorylation. This process is associated with the transfer of a(n) a. phosphate group to a substrate. b. None of the above is correct c. phosphate group to a protein. d. phosphate group to an ADP. e. ADP to a protein.
phosphate group to an ADP
A molecule that has probably the greatest effect on regulating the rate that glycolysis proceeds is: a. oxygen availability. b. lactate dehydrogenase. c. phosphofructokinase. d. availability of FAD e. citrate synthase.
phosphofructokinase.
Which of these polymerases does not require a template? a. reverse transcriptase b. eukaryotic RNA polymerases c. bacterial RNA polymerase d. DNA polymerase e. All polymerases require a template f. polyadenylate polymerase
polyadenylate polymerase
Nuclear pores allow traffic of __________. a. proteins into the thylakoid lumen b. ribosomal subunits out of the nucleus. c. mRNAs into the nucleus d. mitochondria. e. chromosomes during the prometaphase stage of mitosis.
ribosomal subunits out of nucleus
Which of the following complexes is comprised of RNA and proteins? (more than 1) ribosome centrosome lysosome spliceosome endosome
ribosome, spliceosome
In the circumstance that there are several EPSPs arriving at the axon hillock of a neuron from different dendrites and are depolarizing the postsynaptic cell to threshold resulting in an action potential, this would be an example of: a. spatial summation. b. refractory period. c. inhibitory synapse. d. stimulatory synapse. e. temporal summation.
spatial summation
When Na+ moves into the cell following the opening of Na+ channels, _____________________________. a. the ion charge across the membrane in the area that Na+ moves in will change. b. voltage-gated channels will close. c. K+ ions will move out of the cell to counteract the Na+ moving into the cell. d. depolarization will take place. e. the cell will hyperpolarize.
the ion charge across the membrane in the area that Na+ moves in will change.
Which of the following respiratory systems is NOT closely associated with the blood supply? a. the gills of a fish b. the lungs of a vertebrate c. the skin of an earthworm d. the tracheal system of an insect
the tracheal system of an insect
What gives proteins such a dominant role in the molecular biology of the cell? a. their ability to spontaneously fold into complex three-dimensional structures. b. their ability to act as a blueprint. c. All of these are valid reasons. d. the variation in protein sizes. e. their ability to self-replicate.
their ability to spontaneously fold into complex three-dimensional structures.
Gas exchange in insects is taking place at ________. a. trachea b. alveoli of the lungs c. ears d. at the external gills e. within internal gills
trachea
A red blood cell (RBC) is traveling along an artery of the leg that feeds the foot, and this RBC is in its way to a cell in the big toe to provide oxygen in that cell. What would you suspect if when you measure the oxygen in that specific RBC in the venous side and you realize that no oxygen has been released by that RBC. a. the capillary bed at where that cell is located has been bypassed. b. venules cannot effectively exchange oxygen at the toe. c. two of these answers are correct. d. the arterly delivering blood to the toe is occluded. that RBC did not release any oxygen when passing by that cell.
two of these answers are correct.
Exhanging gases is more difficult for animals in water (use gills) than for terrestrial animals (use lungs) because _____. a. gills cannot operate in the air b. gills do not allow countercurrent blood-water exchange c. gill surface area is lower than that of lungs d. water has much less oxygen per unit volume than air e. water is less dense than air
water has much less oxygen per unit volume than air
When the enviromental temperature increases by 8 degrees Celcius, an endotherm's internal temperature will________________________. a. will decrease. b. rise by 10 degrees Celcius and staty at tht temperature. c. rise by 8 degrees Celcius d. rise by 10 degrees Celcius and drop. e. will not change much.
will not change much
Responses associated with positive feedback _____________________________. a. have long-term effects on the body. b. are more common than negative feedback responses. c. will alter the set point. d. can increase or decrease the error relative to the set point. e. will reach a limit and then stop.
will reach a limit and then stop.