akunuru1236

Match the part of the brain to the appropriate function (each choice will be used once). Question 6 options: houses the reticular formation / bundle of nerve fibers that connects the two cerebral hemispheres / regulation of body functions such as: thirst/hunger, water balance, and body temperature / coordinates posture and balance / coordinate skeletal muscle movements; acts in reasoning, learning, and memory 1. cerebrum 2. brainstem 3. cerebellum 4. corpus callosum 5. hypothalamus

Match the following descriptions of transcription regulators to the appropriate organism type.

often bind to cis-regulatory sequences close to or within the gene promoter

[ Choose ] eukaryote bacteria

often function by promoting or preventing the binding of RNA pol to the gene promoter indirectly, by altering chromatin or interacting with general transcription factors

[ Choose ] eukaryote bacteria

often bind to cis-regulatory sequences far from the gene promoter

[ Choose ] eukaryote bacteria

typically act as activators or repressors depending on what other proteins they bind

[ Choose ] eukaryote bacteria

can act as activators or repressors depending on where they bind relative to the gene promoter

[ Choose ] eukaryote bacteria

Select the correct answer for each question, explain your reasoning for your answer to each question.

1. Which evidence best supports the idea of a critical period for human language development?

A. Deaf infants will not develop language if not provided with sign language at a young age.
B. Babies start verbally “babbling” at about 7 months of age.
C. Hearing infants start manual (hand) “babbling” at about 10 months of age.
D. Word-processing tasks activate the same neuronal network in 7-year-olds as in adults.

2. Which statement regarding critical periods is true?

A. The behavior will not develop without input from the environment.
B. Stimulation from the environment leads to changes in synaptic connections.
C. Neural connections are mostly permanent outside of the critical period timeframe.
D. All of the above

3. Which treatment option might a doctor recommend for an infant patient diagnosed with esotropia (crossed eyes)?

A. Immediate surgical correction
B. Immediate dark stimulation therapy for the affected eye
C. Surgical correction at age 2
D. Dark stimulation therapy for the affected eye at age 2

4. An adult cat is deprived of visual stimulation in one eye for a year. After that time, you record from cells in the visual cortex in response to light stimulus on both eyes. Which outcome would you expect?

A. Most cells are non-responsive.
B. Most cells are activated only by stimulation to the deprived eye.
C. Most cells are activated to some degree by stimulation in both eyes.
D. Most cells are activated only by stimulation to the non-deprived eye.

A consumer is making saving plans for this year and the next. She knows her real income after taxes will be €20,000 in both years. Any part of her income saved this year will earn a real interest rate of 3% between this year and next year. Currently, the consumer has no wealth (no money in the bank or other financial assets, and no debts). There is no uncertainty about the future.

The consumer wants to save an amount this year that will allow her to

(1) make college tuition payments next year equal to €5000 in real terms; 
(2) enjoy exactly the same amount of consumption this year and next year, not counting tuition payments as part of next year’s consumption; and

(3) have neither assets nor debts at the end of next year.

a. How much should the consumer save this year? 
    How much should she consume?

of what would an optimal employment contracts for managers consist when there is revenue risk and unobservable output

a flat salary plus a profit share related only indirectly to individual effort

only a profit share

a flat salary plus a profit share that is equal to the sahre accruing to owners

a flat salary alone

Chromatin Structure

The following sentences describe chromatin structure and how altering chromatin structure can affect gene expression. Complete each sentence using the words provided.

Lack's model for clutch size evolution predicts the optimalnumber of offspring in a clutch as those which produce the mostoffspring. However, experiments often demonstrate that organisms donot produce the predicted optimal clutch size because:

A.

his assumption that offspring receive equal parental investmentis often not met.

B.

his model assumes that there are no carry-over costs amongreproductive events, yet early reproductive investment can affectfuture reproductive success.

C.

his model uses offspring survival as a measure of fitness whichmay be less important in the long run than, for example, thequality of those offspring.

D.

tests of his model often use approaches like adding eggs tonest, which may underestimate the true cost of increasesreproductive investment.

E.

All of the above.

Describe a carbohydrate.

What is the primary subunit of a carboyhydrate?

List the primary functions of carbohydrates.

Describe a lipid.

What is the primary subunit of a lipid? ___________________________

List the primary functions of lipids.

Describe a protein.

What is the primary subunit of a protein? ________________________

__

List the primary functions of proteins.

Describe a nucleic acid.

What is the primary subunit of a nucleic acid?_________________________

List the primary functions of nucleic acids.

Diagram a representation of a glycosidic linkage.

Diagram a representation of a peptide bond.

Draw a representation of glucose.

Draw the disaccharide sucros(circle the glyosidic bond in red)

Draw the tripeptide of glycine-cysteine

–methionine

(circle the peptide bonds in red)

.

Draw the tripeptide of glycine-cysteine–methionine

(circle the peptide bonds in red)

.

Draw a triglyceride where each fatty acid has 10 carbons and one F.A. has 0 double bonds, one

F.A. has 1 double bond and one F.A. has 2 double bonds. Indicate which F.A. are saturated and which are not saturated and circle any ester bonds in red

Diagram a representation of a dehydration (synthesis) reaction.

Diagram a representation of a hydrolysis reaction.

Using fig 2.20 diagrama representation of the following for lecithin Structural formula Space filling model ,Simplified representation

Describe /diagram a representation of each of the following for a protein:

Primary structure

Secondary structure

Tertiary structure

Quaternary structure

.

1. Place the following statements in the correct order to represent the events occurring at a synapse upon the arrival of an action potential. (1, 2, 3, 4, 5 or 6)

Opening of ligand-gated ion channels to allow Na+ or cations to flow into the dendritic spines__

Depolarization of the postsynaptic membrane and generation of action potential__

Ca2+ channels in the presynaptic membrane open and to allow calcium to flow in___

propagation of action potential through the opening of voltage gated channels____

the increase in the concentration of cytosolic Ca2+ in the terminal knob triggers the fusion of synaptic vesicles with the presynaptic membrane___

diffusion of the released neurotransmitter across the synaptic cleft and binding to ion-channel receptors on the postsynaptic membrane___

2. FILL IN THE BLANKS. Plasma membranes are said to be asymmetric because of the unequal distribution of different types of phospholipids in the outer leaflet and the inner leaflet.

1. Which phospholipids are more abundant in the outer leaflet of animal membranes?

Blank 1________

2. Which phospholipids more abundant in the inner leaflet?

Blank 2_________

3. Some lipids termed as Blank 3 ______carry oligosaccharide head-groups and are enriched in the Blank 4 ________ leaflet of the plasma membrane.

4. In animal cells, Blank 5_________is equally distributed between the outer and inner leaflets of the plasma membrane and it modifies membrane fluidity and permeability. Membrane fluidity is also increased by increasing the degree of Blank 6_______ of fatty acid chains

3 .Briefly describe the structure and possible applications of liposomes.

4.Briefly explain the mechanism of function of a ligand gated Na+ channel.

5. Briefly summarize the mechanism of function of a voltage-gated K+ channel.

6. Which of the following proteins or structures are responsible for maintaining resting potential in nerve cells?

A. K+ leak channels

B. Na+/K+ ATPase

C. Na+ leak channels

D. Glucose transporters

7. The class of molecule that mediates most functions in biological membranes is______

A. carbohydrates

B. triglycerides

C. phospholipids

D. proteins

8. The class molecule that is most responsible for the structure of biological membranes is________

A. carbohydrates

B. triglycerides

C. phospholipids

D. proteins

9. Which of the following molecules is likely to be transported by diffusion across a biological membrane?

A. glucose

B. water

C. k+

D. oxygen

10. The difference between active and passive transport is that____

A. ATP is expended during active transport

B. ATP is expended during passive transport

C. Non-polar substances are transported by active transport

D. Non-polar substances are transported by passive transport

11. Cholesterol in biological membranes___

A. increases fluidity

B. decreases fluidity

C. increases freezing temperature

D. has no effect

12. Active transport is achieved by___

A. integral membrane proteins

B. peripheral membrane proteins

C. phospholipids

D. glycolipids

Please explain your choice in detail!

Thanks!

Which of the following statements is NOT correct?

In a non-apoptotic cell, cholesterol is most likely to be found only in:

A) in the same amount in every membrane compartment in the cell, since cholesterol has no preference for a specific type of membrane.

B) in the endoplasmic reticulum

C) the outer leaflet of the plasma membrane

D) the inner leaflet of the plasma membrane.

E) throughout both leaflets of the plasma membrane.

1. In a non-apoptotic cell, cholesterol is most likely to be found only in

2. A specific protein is 208 amino acids long. It has 22 non-polar, uncharged amino acids, which are distributed uniformly through the length of the entire protein (these non-polar, uncharged amino acids are NOT clustered together in one portion of the protein’s primary structure). This protein has no covalent attachments to other types of molecules. Assuming this specific protein is a membrane protein, which type of protein is it most likely to be:

How do phospholipids contribute flexibility to cell membrane structure?

a. The phospholipids containing unsaturated fatty acids cannot be tightly packed which provides membrane flexibility.

b. The phospholipids containing saturated fatty acids cannot be tightly packed which provides membrane rigdidity.

c. The two fatty acid chains are flexible as they are unsaturated and provide the flexibility.

d. The two fatty acid chains are saturated. Embedded cholesterol and proteins provide the flexibility.

How do the unsaturated fatty acids in the phospholipids affect the structure of cell membranes?

a. Because the molecules of the unsaturated fatty acids are large and rigid, they reduce the flexibility of the lipid bilayer and add strength to the cell membrane.

b. The unsaturated fatty acids embedded in the membrane make it stronger and less fluid.

c. The unsaturated fatty acids have kinks in their carbon chains that provide a flexible, not fixed, structure that is dynamic and fluid-like.

d. The unsaturated fatty acids in the membrane emerge on the inner or outer surface only, whereas the saturated fatty acids extend through the membrane to both surfaces.

2. What directly or indirectly determines the transition temperature of a membrane? a. the length of the fatty acid chains b. the extend to which the fatty acid chains of the lipids contain double bonds c. whether the fatty acid chains of the lipids are saturated or unsaturated d. All of the answer choices are correct e. the ability of lipid molecules to be packed together

8. What are these two populations mostly likely to be? a. RED alpha subunit and RED heterodimer b. RED alpha subunit only c. RED alpha subunit and RED beta subunit d. RED beta subunit only e. RED heterodimer only

9. You observe the dynamics of a single, fluorescently-tagged lipid anchored protein in the inner leaflet of a cell membrane. You notice that, although this molecule moves laterally in any direction, it is confined to a small domain. This behavior is best explained by the idea that the lipid-anchored protein: a. is part of a complex of proteins b. is bounded by cytoskeletal elements, such as spectrin c. disproves the fluid mosaic model d. is attached to a protein in the extracellular matrix, such as fibronectin 4

10. Which of the following techniques does NOT make use of antibodies? a. Mass spectrometry b. Western blots c. Blood typing d. Immunofluorescence e. Affinity chromatography

11. If two 15nm structures in a cell are 100nm apart, by which method would you be able to resolve them as two structures instead of one? a. phase contrast microscopy b. electron microscopy c. fluorescence microscopy d. FRET e. confocal microscopy Use the following image to answer the following 3 questions:

17. Why is phosphorylation of the Na+/K+ ATPase pump important for its function? a. It changes the configuration of the protein to open on one side of the cell membrane or the other b. It allows ions to be moved against their concentration gradients in a regulated fashion. c. All of the answer choices are correct. d. It changes the affinity of Na+ binding to the pump e. It utilizes energy in the form of ATP

18. A metabolic pathway must provide the desired chemical (metabolite) at the rate required for cellular and tissue function. To best accomplish this, the reaction sequence _____. a. includes only chemical reactions that are energetically favorable. b. couples energetically unfavorable reactions to ATP condensation in order to drive the reaction toward the required product. c. includes only reactions that are irreversible. d. includes only reactions that are reversible. e. All of the answer choices are correct.

19. Which of the following are places where glycosylated lipids are never observed within a eukaryotic cell? a. In the extracellular leaflet of the cell membrane b. In the lumenal leaflet of the ER c. In the cytosolic leaflet of the golgi d. All of the answer choices are possible sites for glycosylated lipids e. In the interior leaflet of the lysosome

21. Which of the following amino acids would be most likely to form a covalent bond between one polypeptide bond and another? a. tyrosine b. tryptophan c. cysteine d. proline e. asparagine

22. You modify the gene for an integral membrane protein so that the cytoplasmic portions of the protein are deleted. When the gene is inserted in cells, what happens to the mobility of this protein in the membrane? a. It moves much smaller distances than the intact protein b. It flips to the opposite leaflet c. It does not move at all d. It is not inserted into the membrane so nothing can be learned about its mobility e. It moves much greater distances than the intact protein

23. Which of the following tripeptides would be most likely to be soluble in an organic (hydrophobic) solvent? a. N- phenylalanine - alanine - glycine -C b. N- leucine - alanine - lysine -C c. N- proline - phenylalanine - leucine -C d. N- gluatmic acid - aspartate - glycine -C e. N- arginine - lysine - proline -C

24. What causes the refractory period in sodium channels after an action potential has been initiated? The sodium channel cannot be restimulated during this period. a. The sodium channel must close before it can be reopened in response to another stimulus. b. The sodium channel can immediately reopen after the inactivation peptide has swung out of the pore opening. c. The sodium channel must close before it can be reopened in response to another stimulus, and it can only transform from the inactivated to the closed conformation after the inactivating peptide has swung out of the pore opening. d. The ion channel can only transform from the inactivated to the closed conformation after the inactivating peptide has swung out of the pore opening. e. The sodium concentration outside of the cell has been completely depleted.

25. The Prp (protease resistant protein) has two isoforms: PrpC (cellular) and PrpSc (scrapie), which contain identical amino acid sequence. The common form is 43% alpha helical, while the scrapie form is 20% alpha helical and 34% beta sheet. In the misfolded scrapie form, the protein is an infectious agent within brain and neural tissues that leads to neurodegeneration. Which change in protein structure accounts for the large difference between PrpC and PrpSc ? a. primary only b. primary and secondary c. quaternary only d. secondary e. tertiary only 8

26. Why does the fracture plane in the freeze-fracture technique usually pass through the center of cell membranes? a. Fracture planes take the path of least resistance through the block and the center of the membrane. b. Fracture planes are repelled by the cytoplasm and pushed toward the membrane. c. Fracture planes take the path of highest resistance through the block and the center of the membrane. d. Fracture planes are attracted to the hydrophobic phospholipid tails e. Fracture planes are naturally attracted to lipids.

27. What kind of membrane protein is found entirely outside the bilayer on either the extracellular or cytoplasmic surface? These proteins are covalently linked to a membrane lipid situated within the lipid bilayer. a. integral protein b. peripheral protein c. carbohydrate-anchored protein d. transmembrane e. lipid-anchored protein

28. Which of the following amino acids would be most likely to form a covalent interaction with a carbohydrate? a. tryptophan b. asparagine c. tyrosine d. proline e. cysteine

29. Why do electon microscopes provide much greater resolving power than light microscopes? a. because the numerical aperture is much smaller in electron microscopes b. because the wavelength of an electron is much lower than that of visible light c. because more electrical power is involved in running an electron microscope d. because the numerical aperture is much larger in electron microscopes e. because the wavelength of an electron is much higher than that of visible light

30. Carbon dioxide binds to hemoglobin at a distinct site from where oxygen binds. However, CO2 binding causes a conformational change in hemoglobin that decreases the protein’s binding affinity for O2. What kind of interaction does this describe? a. allosteric interaction b. covalent binding c. competitive inhibition d. catalyzed interaction e. irreversible inhibition 9 Use this information to answer the following 3 questions. You treat some cells with a protease (an enzyme that hydrolyzes polypeptide bonds) that is too large to penetrate the cell membranes in order to study four integral proteins: W, X, Y and Z. You repeat the experiment under three different conditions: In Set 1, you treat intact cells with the protease. In Set 2, you make the cells permeable to the protease prior to treatment with the protease. In Set 3, you do not make the cells permeable or treat with protease. Proteins are then extracted from the three different sets of cells and applied to an SDS-PAGE gel. The following gel was obtained from this experiment.

34. Which of the following is a technique used to isolate a particular organelle in bulk so that its function can be studied? a. selective precipitation b. differential interference contrast microscopy c. autoradiography d. affinity chromatography e. differential centrifugation

35. As an action potential is initiated, the membrane is ________. This is caused by the _____ of _____ ions. a. depolarized, influx, Na+ b. hyperpolarized, influx, Na+ c. hyperpolarized, efllux, Na+ d. depolarized, influx, K+ e. depolarized, efflux, Na+

36. You are studying a voltage-gated ion channel. When you change the membrane potential by an electrical stimulus to open the gate, you observe cation flow into the cell. Based on the concentrations of the following substances inside and outside of a typical mammalian cell, which of them is the most likely to travel through this channel? a. K+ b. Na+ and K+ c. H+ d. Cle. Na+

37. Which of the following amino acids would be most likely to form a covalent interaction with a phosphate group? a. cysteine b. tryptophan c. asparagine d. proline e. tyrosine

38. A patient with AB blood type expresses which antibodies? a. Anti-A antibody b. neither Anti-A or Anti-B antibodies c. Anti-B antibody d. both Anti-A and Anti-B antibodies

39. What kind of interaction is not involved in the binding of a substance to a normally functioning enzyme? a. H bonds b. hydrophobic interactions c. ionic bonds d. a permenant covalent bond e. a transient covalent bond 11

40. When membrane lipids are extracted from cells and used to prepare artificial lipid bilayers, cholesterol and sphingolipids tend to self-assemble into __________ that are more gelated and highly ordered than surrounding regions consisting primarily of _________. a. lipid rafts, phosphoglycerides b. liquid crystals, integral proteins c. liposomes, phosphoglycerides d. lipid rafts, integral proteins e. macrodomains, phosphoglycerides

41. In which chromatographic method are proteins separated based on their charge? a. ion exchange chromatography b. SDS-PAGE c. affinity chromatography d. immunoprecipitation e. gel filtration

1. In a living organism, where are stable ionic bonds most likely to be found? a. between DNA strands b. deep in a protein’s core where water is excluded c. on the surface of a protein d. in the center of a lipid bilayer e. in the cytoplasm

2. What directly or indirectly determines the transition temperature of a membrane? a. the length of the fatty acid chains b. the extend to which the fatty acid chains of the lipids contain double bonds c. whether the fatty acid chains of the lipids are saturated or unsaturated d. All of the answer choices are correct e. the ability of lipid molecules to be packed together

8. What are these two populations mostly likely to be? a. RED alpha subunit and RED heterodimer b. RED alpha subunit only c. RED alpha subunit and RED beta subunit d. RED beta subunit only e. RED heterodimer only

9. You observe the dynamics of a single, fluorescently-tagged lipid anchored protein in the inner leaflet of a cell membrane. You notice that, although this molecule moves laterally in any direction, it is confined to a small domain. This behavior is best explained by the idea that the lipid-anchored protein: a. is part of a complex of proteins b. is bounded by cytoskeletal elements, such as spectrin c. disproves the fluid mosaic model d. is attached to a protein in the extracellular matrix, such as fibronectin 4

10. Which of the following techniques does NOT make use of antibodies? a. Mass spectrometry b. Western blots c. Blood typing d. Immunofluorescence e. Affinity chromatography

11. If two 15nm structures in a cell are 100nm apart, by which method would you be able to resolve them as two structures instead of one? a. phase contrast microscopy b. electron microscopy c. fluorescence microscopy d. FRET e. confocal microscopy Use the following image to answer the following 3 questions:

17. Why is phosphorylation of the Na+/K+ ATPase pump important for its function? a. It changes the configuration of the protein to open on one side of the cell membrane or the other b. It allows ions to be moved against their concentration gradients in a regulated fashion. c. All of the answer choices are correct. d. It changes the affinity of Na+ binding to the pump e. It utilizes energy in the form of ATP

18. A metabolic pathway must provide the desired chemical (metabolite) at the rate required for cellular and tissue function. To best accomplish this, the reaction sequence _____. a. includes only chemical reactions that are energetically favorable. b. couples energetically unfavorable reactions to ATP condensation in order to drive the reaction toward the required product. c. includes only reactions that are irreversible. d. includes only reactions that are reversible. e. All of the answer choices are correct.

19. Which of the following are places where glycosylated lipids are never observed within a eukaryotic cell? a. In the extracellular leaflet of the cell membrane b. In the lumenal leaflet of the ER c. In the cytosolic leaflet of the golgi d. All of the answer choices are possible sites for glycosylated lipids e. In the interior leaflet of the lysosome

21. Which of the following amino acids would be most likely to form a covalent bond between one polypeptide bond and another? a. tyrosine b. tryptophan c. cysteine d. proline e. asparagine

22. You modify the gene for an integral membrane protein so that the cytoplasmic portions of the protein are deleted. When the gene is inserted in cells, what happens to the mobility of this protein in the membrane? a. It moves much smaller distances than the intact protein b. It flips to the opposite leaflet c. It does not move at all d. It is not inserted into the membrane so nothing can be learned about its mobility e. It moves much greater distances than the intact protein

23. Which of the following tripeptides would be most likely to be soluble in an organic (hydrophobic) solvent? a. N- phenylalanine - alanine - glycine -C b. N- leucine - alanine - lysine -C c. N- proline - phenylalanine - leucine -C d. N- gluatmic acid - aspartate - glycine -C e. N- arginine - lysine - proline -C

24. What causes the refractory period in sodium channels after an action potential has been initiated? The sodium channel cannot be restimulated during this period. a. The sodium channel must close before it can be reopened in response to another stimulus. b. The sodium channel can immediately reopen after the inactivation peptide has swung out of the pore opening. c. The sodium channel must close before it can be reopened in response to another stimulus, and it can only transform from the inactivated to the closed conformation after the inactivating peptide has swung out of the pore opening. d. The ion channel can only transform from the inactivated to the closed conformation after the inactivating peptide has swung out of the pore opening. e. The sodium concentration outside of the cell has been completely depleted.

25. The Prp (protease resistant protein) has two isoforms: PrpC (cellular) and PrpSc (scrapie), which contain identical amino acid sequence. The common form is 43% alpha helical, while the scrapie form is 20% alpha helical and 34% beta sheet. In the misfolded scrapie form, the protein is an infectious agent within brain and neural tissues that leads to neurodegeneration. Which change in protein structure accounts for the large difference between PrpC and PrpSc ? a. primary only b. primary and secondary c. quaternary only d. secondary e. tertiary only 8

26. Why does the fracture plane in the freeze-fracture technique usually pass through the center of cell membranes? a. Fracture planes take the path of least resistance through the block and the center of the membrane. b. Fracture planes are repelled by the cytoplasm and pushed toward the membrane. c. Fracture planes take the path of highest resistance through the block and the center of the membrane. d. Fracture planes are attracted to the hydrophobic phospholipid tails e. Fracture planes are naturally attracted to lipids.

27. What kind of membrane protein is found entirely outside the bilayer on either the extracellular or cytoplasmic surface? These proteins are covalently linked to a membrane lipid situated within the lipid bilayer. a. integral protein b. peripheral protein c. carbohydrate-anchored protein d. transmembrane e. lipid-anchored protein

28. Which of the following amino acids would be most likely to form a covalent interaction with a carbohydrate? a. tryptophan b. asparagine c. tyrosine d. proline e. cysteine

29. Why do electon microscopes provide much greater resolving power than light microscopes? a. because the numerical aperture is much smaller in electron microscopes b. because the wavelength of an electron is much lower than that of visible light c. because more electrical power is involved in running an electron microscope d. because the numerical aperture is much larger in electron microscopes e. because the wavelength of an electron is much higher than that of visible light

30. Carbon dioxide binds to hemoglobin at a distinct site from where oxygen binds. However, CO2 binding causes a conformational change in hemoglobin that decreases the protein’s binding affinity for O2. What kind of interaction does this describe? a. allosteric interaction b. covalent binding c. competitive inhibition d. catalyzed interaction e. irreversible inhibition 9 Use this information to answer the following 3 questions. You treat some cells with a protease (an enzyme that hydrolyzes polypeptide bonds) that is too large to penetrate the cell membranes in order to study four integral proteins: W, X, Y and Z. You repeat the experiment under three different conditions: In Set 1, you treat intact cells with the protease. In Set 2, you make the cells permeable to the protease prior to treatment with the protease. In Set 3, you do not make the cells permeable or treat with protease. Proteins are then extracted from the three different sets of cells and applied to an SDS-PAGE gel. The following gel was obtained from this experiment.

34. Which of the following is a technique used to isolate a particular organelle in bulk so that its function can be studied? a. selective precipitation b. differential interference contrast microscopy c. autoradiography d. affinity chromatography e. differential centrifugation

35. As an action potential is initiated, the membrane is ________. This is caused by the _____ of _____ ions. a. depolarized, influx, Na+ b. hyperpolarized, influx, Na+ c. hyperpolarized, efllux, Na+ d. depolarized, influx, K+ e. depolarized, efflux, Na+

36. You are studying a voltage-gated ion channel. When you change the membrane potential by an electrical stimulus to open the gate, you observe cation flow into the cell. Based on the concentrations of the following substances inside and outside of a typical mammalian cell, which of them is the most likely to travel through this channel? a. K+ b. Na+ and K+ c. H+ d. Cle. Na+

37. Which of the following amino acids would be most likely to form a covalent interaction with a phosphate group? a. cysteine b. tryptophan c. asparagine d. proline e. tyrosine

38. A patient with AB blood type expresses which antibodies? a. Anti-A antibody b. neither Anti-A or Anti-B antibodies c. Anti-B antibody d. both Anti-A and Anti-B antibodies

39. What kind of interaction is not involved in the binding of a substance to a normally functioning enzyme? a. H bonds b. hydrophobic interactions c. ionic bonds d. a permenant covalent bond e. a transient covalent bond 11

40. When membrane lipids are extracted from cells and used to prepare artificial lipid bilayers, cholesterol and sphingolipids tend to self-assemble into __________ that are more gelated and highly ordered than surrounding regions consisting primarily of _________. a. lipid rafts, phosphoglycerides b. liquid crystals, integral proteins c. liposomes, phosphoglycerides d. lipid rafts, integral proteins e. macrodomains, phosphoglycerides

41. In which chromatographic method are proteins separated based on their charge? a. ion exchange chromatography b. SDS-PAGE c. affinity chromatography d. immunoprecipitation e. gel filtration

It is easier for selection to act on alleles that have effectsearly in life relative to those that have effects late in life.This is because

T or F. The amount of time that two interacting proteins will remain bound together

is largely dependent upon the combined strength of the hydrogen and electrostatic

(ionic) bonds that form between the two proteins.

T or F. In enzyme regulation by positive regulation, the enzyme will be in an inactive

state when the regulatory molecule is not bound to the enzyme.

T or F. Alpha-helices and beta-sheets are important secondary protein structures

that form due to hydrogen bonding involving atoms in the peptide backbone.

T or F. Protein function can be reversibly regulated by the covalent addition/removal

of an ATP molecule to one of its amino acid side chains.

T or F. Protein kinases are enzymes that transfer the phosphate group of a

phosphorylated protein to the hydroxyl group of a serine, threonine, or tyrosine amino

acid side chain.

T or F. Ion-channel coupled receptor activity is regulated by the ions that pass

through the ion channel.

T or F. The amount of time that two interacting proteins will remain bound together

is largely dependent upon the combined strength of the hydrogen and electrostatic

(ionic) bonds that form between the two proteins.

1. What types of biological macromolecules are most cell walls and extracellular matrices composed of? (Choose ALL correct answers)

2. What is a "second messenger"?

3. How can the activation of a protein kinase be important in signal transduction?

please answer all the questions answering only one question is not helpful!
Question 1

0 / 1 pts

Which of the following E. coli strains with the lac genotypes will synthesize beta-galactosidase in the presence of lactose?

Note: Superscript wouldn't work in the answers, so for example, lacIs means lacI^s(superrepressor of lacI)

lacI– lacP– lacO– lacZ– lacY–

lacIs lacP+ lacO+ lacZ+ lacY– / lacI+ lacP+ lacO+ lacZ– lacY+

lacIs lacP– lacO+ lacZ– lacY+ / lacI+ lacP+ lacO+ lacZ+ lacY+

lacI– lacP– lacO+ lacZ+ lacY+

lacI+ lacP+ lacO+ lacZ+ lacY+

Question 2

0 / 1 pts

Some mutations in the trp 5' UTR region increase termination by the attenuator. An example of a mutation that may have this effect is a

Choose the best answer!

mutation that changes the bases in region 3 of the 5' UTR, such that they no longer pair with region 2 or 4.

deletion of the two tryptophan codons in the 5' UTR leader peptide.

deletion in region 2 in the 5' UTR that prevents it from pairing with region 3.

The second and third answers are correct.

The first, second, and third answers are correct.

IncorrectQuestion 3

0 / 1 pts

Several examples of antisense RNA regulating translation in bacterial cells have been discovered. If you wanted to design a construct to artificially control translation of a bacterial gene with antisense RNA, what type of sequences should the antisense RNA contain?

A sequence complementary to the operator of an operon.

A sequence complementary to a 5' UTR.

A sequence complementary to the Shine-Dalgarno site of the mRNA.

The first and second choices are correct.

The second and third choices are correct.

Question 4

0 / 1 pts

Which of the following correctly describes the function of microRNAs?

Choose the best answer.

MicroRNAs are encoded by genes in the genome of an organism.

MicroRNAs form mRNA which encodes a protein repressor for another gene.

MicroRNAs encode a mRNA that base pairs with itself, forming double stranded RNA.

MicroRNAs are cut into small pieces, then bound by the complex of proteins called RISC to repress the translation of other mRNAs in the cell.

The first and second answers are correct.

The first, third, and fourth answers are correct.

The third and fourth answers are correct.

"Helps fix nitrogen in soil. Boost pea and bean yields with Garden Soil Inoculant. Simply shake granules into furrows as you plant. It contains nitrogen-fixing bacteria to promote stronger root systems and larger harvests. Easy-to-use sprinkler top makes application a snap. 8.7-oz. container treats a 150' row." This product is recommended for growing plants such as beans and peas, for all of the following reasons EXCEPT: These plants can convert nitrogen gas to ammonia

These plants can convert nitrogen gas to ammonia

These plants form symbiotic relationships with bacteria in the product.

These plants are legumes.

These plants produce root nodules that harbor bacteria.

Molecular nitrogen (nitrogen gas) makes up 78% of the Earth’s atmosphere, but is unavailable for use by all organisms except for some nitrogen-fixing ____. (Choose all correct answers.)

bacteria

cyanobacteria

eukaryotes

prokaryotes

fungi

Protists

Nitrogen gas is a chemically inert molecule. The prokaryotes that fix-nitrogen produce the enzyme nitrogenase. What does this enzyme do that allows these organisms to use nitrogen gas? (Hint: You might want to consult a chemistry book to help you with this answer.)

In biological nitrogen fixation (N2, ammonia, hydrogen, oxygen), is (Reduced, oxidized) when it accepts atoms, resulting in the production of (nitrogen gas, nitrate, water, ammonia ) .

Legumes produce (nitrogen, nitrogenase, lehemoglobin,oxygen ,bacteria) , which regulates the amount of (nitrogen, nitrogenase, lehemoglobin,oxygen ,bacteria) present in the root nodule so (nitrogen, nitrogenase, lehemoglobin,oxygen ,bacteria) activity is not inhibited.

Humans and other animals acquire their nitrogen from which of the following? (Choose all correct answers.)

protein from animals that eat other animals

protein from animals that eat plants

plant protein

protein from legumes

The nitrogen sources used by humans are (organic, inorganic) componds, while nitrogen gas is an (organic, inorganic) compound.

1. Consider the following eight statements about vertebrae. Which four of the following eight statements are TRUE? Choose all four correct answers.

(a) In Actinopterygii, Chondrichthyes, and some Amphibia (and one unusual taxon of Lepidosauria), the vertebrae have centra which surround the notochord.

(b) Some vertebrae have processes such as spines that function as sites for muscle attachment.

(c) in many vertebrate taxa, the vertebrae are composed of dermal bone.

(d) In tetrapods, the vertebrae have processes called zygapophyses that function as specialized sites for articulation with the ribs.

(e) Vertebrae arise from sclerotome epimere mesoderm.

(f) All extant vertebrate taxa have vertebrae.

(g) Some vertebrae have hemal arches which protect blood vessels (such as the dorsal aorta).

(h) Vertebrae have neural arches which protect the notochord.

2. While walking through the halls of the Biosciences building, you find a single vertebra lying on the floor. You notice that it does not have zygapophyses. It has an amphicoelous centrum, and it has both a neural arch and a hemal arch. This vertebra is completely ossified. Identify to which vertebrate taxon this vertebra belongs, and to which region of the vertebral column.

(a) caudal region - Petromyzontida

(b) thoracic region - Aves

(c) trunk region - Chondrichthyes

(d) trunk region - Actinopterygii

(e) caudal region - Actinopterygii

(f) caudal region - Amphibia

(g) caudal region - Chondrichthyes

3. You are doing a study on the diet of polar bears. While examining the scat (droppings) of a large polar bear, you find a single vertebrae. You need to identify this vertebra to determine what this polar bear has been eating. Polar bears are known to eat mammals, birds, and some fish (Actinopterygii). This vertebra has a heterocoelous centra and it has no articulation sites for ribs. It also has an odontoid process. To which of these three vertebrate taxa, and to which region of the vertebral column does this vertebra belong?

(a) synsacral region - Aves

(b) cervical region - Mammalia

(c) trunk region - Actinopterygii

(d) cervical region - Aves

(e) caudal region - Actinopterygii

(f) thoracic region - Mammalia

4. Which four of the following eight statements about the skeleton are TRUE? (Choose all four correct options.)

(a) Bone is a tissue that is able to withstand large tensile forces but not large compressive forces.

(b) An important role of the vertebral column in actinopterygii and chondrichthyes is to support the body weight.

(c) in amniotes, the ribs consist of two parts, a costal rib (which articulates with a thoracic vertebra) and a sternal rib (which articulates with the sternum). The mobile joints between the costal and sternal rib, as well as between the costal rib and the vertebra and between the sternal rib and the sternum, make the ribcage flexible such that it can expand during breathing.

(d) A vertebral column with procoelous centra would have a greater range of mobility than a vertebral column with acoelous centra.

(e) In all extant vertebrate taxa, the vertebral column provides axial structural support, as well as support for locomotion.

(f) In many mammals, ligaments and muscles attaching to the neural spines of vertebrae help to stabilize the vertebral column and pull it into a stable arch, which helps to efficiently bridge the body weight to the legs.

(g) In tetrapods, the pectoral girdle is firmly fused to the vertebral column to allow for efficient transfer of locomotive forces from the forelimbs to the axial skeleton.

(h) In chondrichthyes, actinopterygii, sarcopterygii, and some tetrapods, the vertebral column acts as a firm but flexible rod on which muscles pull to produce lateral undulations of the body for locomotion.

5. Consider the following eight statements about the form and function of the appendicular skeleton. Which four of the following eight statements are TRUE? (Choose all four correct options.)

(a) In sharks (Chondrichthyes), the pectoral and pelvic fins are mainly used for propulsion - to propel the body forward through the water.

(b) The tips of fins are supported by fin rays, thin rods which support a webbing of skin (and sometimes also connective tissue) - this increases the surface area of the fin

(c) The fleshy fins of sarcopterygii are not very maneuverable, and are used only to stabilize the body by preventing roll, pitch, and yaw when swimming rapidly.

(d) In both actinopterygii and chondrichthyes, the pectoral girdle attaches directly to the back of the skull while the pelvic girdle is embedded in the muscle of the body wall.

(e) In both sharks (Chondrichthyes) and actinopterygii, the pectoral and pelvic fins provide stability while swimming by preventing roll, pitch, and yaw.

(f) In male chondrichthyes, the pelvic fins have special extensions called claspers that are used to transfer sperm to females during copulation for internal fertilization.

(g) Petromyzontida and myxinoidea have paired pectoral and pelvic fins that are used to provide stability while swimming, as well as for steering.

(h) The main functions of girdles are to provide attachment sites for the muscles of the appendages (paired fins or limbs) and to stabilize the appendages.

6. Consider the following statements related to the appendicular skeleton and terrestrial locomotion of tetrapods. Which three of the following six statements are CORRECT? (Choose all three correct options.)

(a) In tetrapods with erect limb posture, the limbs are positioned directly under the body, while in tetrapods with sprawled limb posture, the limbs are positioned to the sides of the body.

(b) In terrestrial tetrapods, the distal ends of the humerus and femur are rotated such that the digits are oriented in line with the direction of travel, increasing both tractive and propulsive forces during terrestrial locomotion.

(c) Tetrapods with digitigrade foot posture have relatively longer limbs than tetrapods with plantigrade foot posture, such that they have a greater stride length.

(d) When terrestrial tetrapods are walking or running, the recovery stroke of the limbs involves the limb touching the ground while the propulsive stroke of the limbs involves the limb being lifted and moving from posterior to anterior.

(e) In tetrapods with sprawled limb posture, the dorsal elements of the pectoral girdle (such as the scapula) are much larger than the ventral elements of the pectoral girdle (such as the clavicle and corocoid).

(f) When walking or running, tetrapods with erect limb posture use an overarm swing for the recovery stroke, which is relatively slow.

7. You are walking along the beach and find a skeleton in the sand. You notice that the pelvic girdle is not fused to the vertebral column while the pectoral girdle is fused to the skull. The distal ends of the appendages have fin rays. It appears that all muscles controlling the appendages were located within the body wall, not within the appendages. To which vertebrate taxon does this skeleton belong?

(a) Sarcopterygii

(b) Lepidosauria

(c) Elasmobranchii

(d) Amphibia

(e) Actinopterygii

(f) Petromyzontida

8. Your neighbour finds a skeleton while cleaning out the pond in her backyard, and she asks you to identify it. You notice that the vertebrae have zygapophyses and that the centra of the vertebrae are procoelous. The ribs are quite short, and articulate with the vertebrae but not with the sternum. The pelvic and pectoral girdles appear robust and highly ossified, and the pectoral girdle has enlarged ventral elements but relatively small dorsal elements. The appendages each have five digits. Identify this skeleton for your neighbour, and describe to her as much as you can about its style of locomotion, based on this information about its axial and appendicular skeleton. (Choose all three correct options.)

(a) This skeleton is most likely from an amphibian.

(b) This skeleton is most likely from a sarcopterygian.

(c) This skeleton is most likely from a lizard (Lepidosauria).

(d) This animal most likely had sprawled limb posture.

(e) This animal most likely could not support its own body weight using its appendages, and so would not have been capable of terrestrial locomotion.

(f) This animal probably walked with lateral undulations of the body, using the feet as pivot points.

(g) This animal most likely walked with a recovery stroke that used an energetically efficient pendulum-like swing.

(h) This skeleton is most likely from a crocodilian (Archosauria).

Imagine a red blood cell containing 300 mOsm NaCl is placed in a solution containing 100 mOsM NaCl and 200 mOsM urea. The solution is therefore (hyposmotic, hyperosmotic, or isomotic) and (hyposmotic, hyperosmotic, or isosmotic) to the cell and therefore the cell volume would (decrease, increase, or stay the same size). Please choose the three correct answers from the parentheses and explain.

True or False: Write TRUE if the statement is correct and write FALSE if the statement has incorrect information. If the statement is FALSE, identify the incorrect information and provide further  explanations, complete solutions, and examples to support your answer. 

5. The concept of evolution has been known for over 3,000 years. Charles Darwin, the father of  evolution, devised a logical explanation for how evolution works. Darwin defined "descent with  modification" as the theory that species change over time, give rise to new species, and share a  common ancestor. Natural selection is the mechanism hypothesized by Darwin that states that  physical changes, such as increased development of an organ (neck) due to increasing use (like in  the case of giraffes), could be passed down to their offspring