Session 3 Flashcards by Margaret Quaid

Which of the following statements is TRUE?
A. The sodium-potassium (Na+ / K+) pump is an active transport system
B. Osmosis is the diffusion of water across a membrane
C. Diffusion involves the movement of substances against a concentration gradient.
D. A and B
E. B and C

D. A and B

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Which of the following features are COMMON to both active transport systems and passive transport via facilitated diffusion using a carrier molecule (transporter)?
A. Specificity
B. Requirement for metabolic energy
C. Presence of a transport maximum
D. A and B
E. A and C

E. A and C

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Which of the following statements regarding the active transport of molecules across cell membranes is correct?
A. Both primary and secondary active transport are dependent upon energy ultimately derived from ATP
B. In secondary active-transport systems in which Na+ ions are bound to carriers, the actively transported solute always crosses the membrane in the same direction as Na+ ions
C. Primary active transport is directly dependent upon ATP hydrolysis whereas secondary active transport is indirectly dependent upon the hydrolysis of ATP which creates an ion (electrochemical) gradient.
D A and B
E. A and C

E. A and C

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Which of the following would increase flux of a solute across a membrane?
A. Increasing temperature
B. Decreasing the solute concentration difference across the membrane
C. Decreasing the density of the medium through which the solute was traveling.
D. A and B
E. A and C

E. A and C

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The direction of diffusion always occurs from areas of high concentration of a molecule to areas of low concentration.
TRUE FALSE

true

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Primary active transport of Na+ across the intestinal epithelium involves Na+ moving across the apical membrane into the cell by facilitated diffusion down its concentration gradient, followed by primary active transport across the basolateral membrane to the outside of the cell.

TRUE FALSE

true

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Two forces drive the diffusion of ions across cell membranes

chemical gradient and eletrical force

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Mary has a 1liter solution containing of 100 mOsm NaCl and 200 mOsm urea.
What is the osmolarity of Mary’s solution?
A. 300 mOsm
B. 350 mOsm
C. 400 mOsm
D. 450 mOsm
E. Cannot tell from this information

C. 400 mOsm

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Mary’s solution is:
A. hypoosmotic, hypotonic
B. hyperosmotic, hypertonic
C. hyperosmotic, isotonic
D. hyperosmotic, hypotonic
E. isosmotic, isotonic

D. hyperosmotic, hypotonic

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If red cells were placed in Mary’s solution, they would be expected to:
A. shrink
B. swell
C. no change volume

B. swell

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Which of the following in TRUE?
A. Receptor signaling is initiated when a chemical messenger binds to the ligand-binding site of the receptor
B. Binding to a receptor is the first step leading to the ultimate response of a cell to the messenger
C. Always occurs at the cell surface
D. A and B
E. A and C

D. A and B

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A lipid-insoluble (hydrophilic) hormone, X, which binds to a cell surface receptor causes a rapid increase in the concentration of protein Y. This is likely because the hydrophilic hormone X acts to
A. Increase the release of protein Y from intracellular vesicles
B. Increase the transcription of genes encoding protein Y.
C. Decrease the breakdown of protein Y mRNA.
D. A and B
E. A and C

A. Increase the release of protein Y from intracellular vesicles

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Cystic fibrosis is an autosomal recessive, single gene disease. Which of the following is TRUE concerning cystic fibrosis?
a. If one child in a family has cystic fibrosis, each parent must either have the disease or be a carrier of the disease.
b. If a mother has cystic fibrosis but a father does not, all children will either carry the disease or be affected by the disease.
c. If one child in a family has cystic fibrosis, all other children will either carry the disease or be affected by the disease.
d. A and B
e. A, B, and C

d. A and B

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Which of the following process is NOT a source of genetic diversity in humans?
a. Recombination during meiosis
b. Independent assortment during mitosis
c. Fertilization
d. A and B
e. A and C

b. Independent assortment during mitosis

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When lipid soluble (hydrophobic) messengers bind to their receptor the resulting response is usually slower and longer lived than when lipid-insoluble (hydrophilic) messengers bind their specific receptors.
TRUE FALSE

true

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It an individual has a male genotype they will always be a phenotypic male.

TRUE FALSE

false

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Hemophilia A and hemophilia B are X-linked recessive diseases. Thus, boys are more frequently affected by these diseases than girls.
TRUE FALSE

true

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Meiosis results in a set of two haploid (1n) daughter cells that are genetically different.

TRUE FALSE

false

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All inherited diseases are congenital diseases, but not all congenital diseases are inherited diseases.
TRUE FALSE

true

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Changes in chromosomal number usually occur by the process of nondisjunction occurring during meiosis.
TRUE FALSE

true

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Regression of the Wolffian duct and persistence of the Mullherian duct is a characteristic of the male fetus.

TRUE FALSE

false

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Germline mutations are transmitted to the offspring of an individual.
TRUE FALSE

true

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What is the chance an AA child will be born to Aa-AA parents?
a. 50%
b. 75%
c. 0%
d. 25%
e. 100%

a. 50%

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A _________ mutation causes an amino acid substitution in a protein. Such mutations may change the structure of a protein so as to increase the risk of disease.
a. Silent
b. Nonsense
c. Missense
d. Frameshift
e. None of the above

c. Missense

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1. Diffusion A. Depends upon the random motion of molecules B. Results in net movement of molecules from regions of low concentration to regions of high concentration C. Is important for moving molecules over large distances in the body D. Requires energy in the form of ATP to be carried out E. Includes all of the choices

A. Depends upon the random motion of molecules

2. Which of the following statements regarding the movement of molecules across cell membranes is correct? A. The diffusion of molecules across a cell membrane occurs at a rate that is influenced by the surface area of the membrane and the magnitude of the concentration difference across it B. The net flux of molecules that cross cell membranes by diffusion is always from regions of lower concentration to regions of higher concentration C. Molecules that enter a cell by diffusion must directly permeate the lipid portion of the plasma membrane, whereas those that enter by facilitated diffusion utilize membrane-bound proteins D. A and B E. A and C

E. A and C

3. Mediated transport across cell membranes A. Refers to the movement of ions through protein channels Mediated refers to transporters mediating the movement. B. Refers both to simple diffusion and to the active transport of molecules C. Is characterized by saturable carriers and a maximum velocity of transport D. A and B E. A and C

C. Is characterized by saturable carriers and a maximum velocity of transport

4. Which of the following statements regarding the active transport of solutes across cell membranes is correct? A. Primary active transporters are ATPases and secondary active transporters are not B. Secondary active transporters require binding of Na ion on the extracellular side of the membrane to transport other solutes either into or out of the cell C. Solutes transported across cell membranes by primary active transport include glucose, Na ion and Ca ion D. A and B E. All of the choices are correct

D. A and B

5. Which of the following is a feature that distinguishes active transport from facilitated diffusion with a transporter? A. Saturability B. Requirement for a carrier molecule C. Specificity D. Presence of a transport maximum E. Requirement for metabolic energy

E. Requirement for metabolic energy

6. Which of the following statements about the Na, K pump is false? A. It transports Na+ out of cells and K+ into cells B. It binds to and hydrolyzes ATP C. It is constantly active in all cells D. Its activity requires the expenditure of metabolic energy E. It transports Na+ and K+ in a 1:1 ratio

E. It transports Na+ and K+ in a 1:1 ratio

7. A cell is placed into a 1 millimolar solution of substance X and over time you witness the concentration of X inside the cell increase to 5 millimolar. The best explanation for this is: A. X is moving into the cell by simple diffusion B. X is moving into the cell by diffusion through a protein channel C. X is moving into the cell by facilitated diffusion D. X is moving into the cell by primary active transport E. A and B

D. X is moving into the cell by primary active transport

8. "Osmosis" refers to the movement of ____________ across semipermeable membranes. A. Glucose B. Charged particles C. Lipid molecules D. Water E. Any substance

D. Water

9. If a cell is placed in a hypotonic solution, it A. Will swell B. Will shrink C. Will stay the same size D. May swell, shrink or stay the same size, depending upon the concentration of penetrating and nonpenetrating solutes in the solution

A. Will swell

10. If a cell is placed in a hyperosmotic solution, it A. Will swell B. Will shrink C. Will stay the same size D. May swell, shrink or stay the same size, depending upon the concentration of penetrating and nonpenetrating solutes in the solution

D. May swell, shrink or stay the same size, depending upon the concentration of penetrating and nonpenetrating solutes in the solution

11. An example of a hypertonic solution is A. 200 mM NaCl contains 200mOsm of non-penetrating Na+ and 200mOsm of non-penetrating Cl-, giving a total of 400 mOsm of non-penetrating solute B. 300 mM glucose C. 100 mM MgCl2 D. 400 mM urea this solution is hyperosmotic, but hypotonic. It contains NO non-penetrating solutes E. None of the choices are correct

A. 200 mM NaCl contains 200mOsm of non-penetrating Na+ and 200mOsm of non-penetrating Cl-, giving a total of 400 mOsm of non-penetrating solute

12. Regarding the tonicity and osmolarity of solutions, which of the following statements is not true? A. The term "tonicity" refers to the effect that a solution has on the degree of stretch or shrinking of the cell membrane B. The term "osmolarity" refers to the osmotic properties of a solution, regardless of its tonicity C. Isotonic solutions are always isoosmotic D. Hypoosmotic solutions are always hypotonic E. Hypertonic solutions are always hyperosmotic

C. Isotonic solutions are always isoosmotic

13. Which of the following are possible combinations of mechanisms for transport of a particle against a concentration gradient across an epithelial cell? A. Passive diffusion from a lumen into the cell followed by facilitated diffusion from the cell into the blood B. Passive diffusion on the apical side into the cell followed by primary active transport on the basolateral side C. Secondary active transport on the mucosal side followed by facilitated diffusion on the serosal side D. A and B E. B and C

E. B and C

14. At any given concentration difference, the rate of diffusion across a permeable surface will be greater for small molecules than for larger ones. TRUE FALSE

true

15. The Na,K-ATPase carrier transports sodium ions out of cells and potassium ions into cells on a one-to-one basis. TRUE FALSE

false

16. Receptors for intercellular messengers are most commonly A. Peripheral membrane proteins B. Integral transmembrane proteins C. Specialized phospholipids within the membrane D. Nucleic acids

B. Integral transmembrane proteins

17. Messages, in the form of chemical signals, are sent from one cell to another with only those capable of receiving the specific chemical able to respond to them. Water soluble signals have receptors A. On the outside of the cell, constituting a component of the plasma membrane B. On the inside of the cell, beyond the boundary of the plasma membrane C. Which have a specific structure complementary to the molecular chemical message being sent D. A and C E. B and C

D. A and C

18. Cellular receptors are classified as either intracellular or as plasma membrane bound receptors. Which of the following is not an integrated trans-plasma membrane receptor related description? A. Binding activates G proteins to, in turn, activate ion channels or enzymes B. Regulation of genetic transcription C. Function as directly regulated ion channels D. Represent membrane bound enzymes, i.e., tyrosine kinases E. bind to and activate JAK kinases

B. Regulation of genetic transcription

19. Two cell types having the same type of receptor for a chemical messenger will always respond to that messenger in the same way. TRUE FALSE

false

20. Cystic fibrosis is an autosomal recessive, single gene disease. Which of the following statements is true concerning cystic fibrosis? A. The disease phenotype of cystic fibrosis can vary from person to person depending upon what type of mutation they have in the cystic fibrosis (CF) gene. B. Only females are affected by cystic fibrosis. C. Only males are carriers of cystic fibrosis. D. A and B E. A, B, and C

A. The disease phenotype of cystic fibrosis can vary from person to person depending upon what type of mutation they have in the cystic fibrosis (CF) gene.

21. The genome of an individual consists of their total DNA content which is densely packaged into chromosomes. True False

true

22. While a locus refers to a unit of heredity, a gene refers to a specific position on a chromosome. True False

false

23. What are the two parts of the cell cycle? A. apoptosis and interphase B. mitosis and cytokinesis C. nucleus and cytoplasm D. mitosis and meiosis E. interphase and cell division

E. interphase and cell division

24. External signals such as hormones and growth factors can stimulate a cell to go through the cell cycle. True False

true

25. Germline cells (gametes; eggs and sperm) have 23 unpaired (1n) chromosomes and are called haploid. True False

true

26. If the mother's genotype is aa, all of her eggs will be identical for this trait. True False

true

27. Can two parents that have a genetic disorder ever have a normal child? YES NO

yes

28. X-linked recessive diseases are primarily diseases of females. True False

FALSE

29. Which of the following statements is true? A. The end result of meiosis is the production of gametes. B. Meiosis results in a set of four haploid (1n) daughter cells. C. Mitosis results in a set of four diploid (2n) daughter cells. D. A and B E. A,B and C

D. A and B

30. Unaffected carrier individuals exist for autosomal recessive but not autosomal dominant genetic disorders. True False

true

1. The net flux of a penetrating solute into a cell will increase if the A. Permeability constant for that solute increases B. Temperature increases C. Concentration of that solute in the extracellular fluid increases D. A and C E. All of the choices are correct

E. All of the choices are correct

2. The permeability of the plasma membrane to mineral ions A. Is dependent upon channels formed by proteins B. Varies from one cell to another C. Is affected by differences in electrical charge on the two sides of the membrane D. A and C E. All of the choices are correct

E. All of the choices are correct

Name four ways in which the net solute flux between two compartments across a membrane can be increased.

A. higher temperature = greater net flux B. mass of molecule larger molecule = smaller net flux C. surface area of membrane greater surface area = greater net flux D. diffusion medium denser the medium = smaller the net flux E. membrane chemical composition

4. What two forces (gradients) make up an electrochemical gradient.

Ion concentration gradient and membrane potential (charge) gradient

5. Name three properties of membrane transporters that regulate the magnitude of solute flux across a mediated-transport system

A. the degree of transporter saturation B. the number of transporters in the membrane C. the rate at which the conformational change in the transporter occurs

6. Circle the following statements (may be more than one) which are true concerning transport through ion channels and mediated transport. A. both involve integral membrane proteins B. both show chemical specificity C. the rate of transport is much lower for ion channels D. there is no limit to flux (rate of movement) of molecules across a membrane via either diffusion through an ion channel or mediated transport.

A. both involve integral membrane proteins B. both show chemical specificity

The chemical properties of a receptor ligand.can be used to predict certain general properties of a receptor : ligand interaction and the ensuing elicited signal. Explain how hydrophilic / lipid insoluble ligands and hydrophobic / lipid soluble ligands usually differ in the following: D. The type of receptor they will bind. E. The type of cellular response they will elicit. F. The rapidity with which they elicit a response and the lifespan of that response.

hydrophilic / lipid-insoluble * membrane-spanning receptors (eg. epinephrine, insulin) * signals typically activate rapid, short-lived responses * responses can be of immediate drastic impact hydrophobic / lipid-soluble * cytosolic or nuclear receptors (eg. steroid hormones, thyroid hormones) * signals typically change gene expression * leading to slow but sustained responses

8. Cellular receptors are classified as either intracellular or as plasma membrane bound receptors. Which of the following is not an integrated transmembrane plasma receptor-related description? A. Binding activates G proteins to, in turn, activate ion channels or enzymes B. Regulate gene transcription C. Function as directly regulated ion channels D. Represent membrane bound enzymes, i.e., tyrosine kinases E. Bind to and activate JAK kinases

B. Regulate gene transcription

9. Cocaine lowers the levels of a chemical messenger in the brain called enkephalin. Researchers have found the number of enkephalin receptors to be higher in cocaine addicts than nonaddicted people. This is an example of A. Saturation B. Up regulation C. Antagonism D. Affinity E.Down regulation

B. Up regulatio

10. Methadone is a drug given to treat heroin addicts. It works by binding to the same receptors as heroin but with greater affinity, thereby preventing heroin from binding. This is an example of A. Competition B. Down regulation C. Signal transduction D. Agonistic behavior E. None of the choices are correct

A. Competition

11. Epinephrine activates the cyclic AMP pathway in liver cells. Therefore, epinephrine A. Probably binds a specific transmembrane receptor in these cells B. Elicits its response in liver cells through second messengers C. Probably binds a receptor in the nucleus of liver cells D. A and B E. B and C

D. A and B

12. At very low concentrations, epinephrine causes an artery to vasodilate. At higher concentrations epinephrine causes the same artery to constrict. How can these different effects best be explained? A. There is one type of epinephrine receptor that uses two second messenger systems B. There are two types of epinephrine receptors with different affinities for epinephrine that use two different second messenger systems C. There are two types of receptors for epinephrine that use the same second messenger system D. At higher concentrations epinephrine can pass through the plasma membrane and directly stimulate contraction within the cell

B. There are two types of epinephrine receptors with different affinities for epinephrine that use two different second messenger systems

13. Which of the following statements is true? A. Phosphorylation by protein kinase can stimulate or inhibit the activity of effector proteins B. Ca2+ and cyclic AMP are second messengers C. Epinephrine is a hydrophilic hormone and thus probably binds intracellular receptors. D. A and B E. All of the choices are true

D. A and B

14. Amplification during a second messenger cascade is beneficial because amplification A. Takes small molecules and makes polymers out of them B. Results in the production of more of the first messenger C. Allows a cell to respond to more different hormones D. Allows small amounts of hormones to produce large responses in target cells E. None of the choices are correct

D. Allows small amounts of hormones to produce large responses in target cells

15. Salt (NaCl) has a molecular weight of 58. How many grams of salt are required to make 3 liters of a 0.5M salt solution? Please show your work!!!!

OSMOLARITY QUESTIONS

LOOK AT THEM

20. Frameshift mutations (addition or deletion of one or more bases) in the coding regions of genes can result in proteins with a completely different sequence of amino acids from the original protein (encoded by the non-mutated gene). True False

true

21. Which of the following statements is false? A. A karyotype is s picture of the chromosomes present in a cell. B. Karyotyping can reveal the presence of gross chromosomal abnormalities, such as trisomy 21 (three copies of chromosome 21), the most common cause of Down Syndrome. C. Karyotyping can be used to detect cystic fibrosis, a disease in which there is an inherited poinbt mutation in the cystic fibrosis gene. (Karyotyping will not pick up small gene mutations!) D. A and B E. A, B, and C

C. Karyotyping can be used to detect cystic fibrosis, a disease in which there is an inherited poinbt mutation in the cystic fibrosis gene.

22. A mutation in a gene exon that results in an amino acid change in the protein product of that gene will always result in a protein that functions abnormally or not at all. True False

false

23. It is possible for an individual to be a genotypic male (XY), but to phenotypically have some female physical characteristics. True False

true

24. Which of the following statements is true? A. Both environmental and genetic factors can contribute to some diseases. B. Genetic factors may increase or decrease susceptibility to disease. C. Environmental factors may increase or decrease susceptibility to disease. D. A and B E. A, B, and C

E. A, B, and C

25. The X an Y sex chromosomes are homologous chromosomes. True False

false

26. Which of the following is true? A. Somatic cells fuse in the formation of the zygote at the time of fertilization. B. Somatic cells have 46 chromosomes that occur in 23 pairs. C. Gametes are haploid. D. A and B E. B and C

E. B and C

27. Which of the following statements is true? A. Increasing rates of gene X transcription can increase levels of protein X, which it encodes. B. Increasing the rates of mRNA X translation can increase levels of protein X which is the product of this translation. C. If protein X is secreted, its activity may be regulated by regulating its rate of secretion. D. A and B E. A, B, and C

E. A, B, and C

28. Cystic fibrosis is an autosomal recessive, single gene disease. Which of the following statements is false concerning cystic fibrosis? A. Individuals with cystic fibrosis may have parents who are not affected by the disease. B. If one child in a family has cystic fibrosis, that means all siblings will be affected. C. If one child in a family is affected by cystic fibrosis, that means all siblings will either be affected by the disease or be carriers of the disease. D. A and B E. B and C

E. B and C

29. Somatic cell mutations are heritable and can be transmitted by mother or father to the next generation. True False

false

30. Mutations in exons are never silent. True False

false

31. Mutations occurring in the non-coding regulatory regions of genes do not affect gene expression. True False

false

32. All the information necessary for an organism to exist is contained within its genome. True False

true

33. Recombination, the process during meiosis in which there is an exchange of genetic material between homologous chromosomes, is a basis for genetic diversity in sexually reproducing organisms. True False

true

34. Which of the following is true? A. All cells progress through the cell cycle at a constant rate. B. Progression through the cell cycle is tightly regulated. C. The rate of progression of a cell through the cell cycle can be dependent upon the type of cell and the age of the individual. D. A and B E. B and C

E. B and C

35. Which of the following statements is false? A. An intron is a sequence of DNA that codes for a protein. B. Genes contain both exon and intron sequences. C. DNA is contained within the nucleus of cells. D. A and B E. B and C

A. An intron is a sequence of DNA that codes for a protein.

36. Which of the following is true? A. Somatic cells fuse in the formation of the zygote at the time of fertilization. B. Somatic cells have 46 chromosomes that occur in 23 pairs. C. Gametes are haploid. D. Autosomal chromosomes determine sex. E. B and C

E. B and C

37. Which of the following statements is false? A. For a given gene, there may be one of two or more alternate forms (different versions) of a gene at a given locus. B. Alleles occur in pairs, one from the mother and one from the father. C. An individual can inherit both alleles for a given gene from just one parent. D. A and B E. A and C

C. An individual can inherit both alleles for a given gene from just one parent.

38. Autosomal chromosomes are the 22 pairs of chromosomes that control traits that do not relate to the gender of an individual. These chromosomes are the same in males and females. True False

true

39. Mutations in the regulatory regions of a gene can lead to increased or decreased transcription of that gene. True False

true

40. Which of the following statements is true? A. For a single gene disease "X", any mutations that result in a change in the amino acid sequence of the protein responsible for "X" will result in disease. B. Changes in genotype always lead to changes in phenotype. C. Some diseases demonstrate an array of disease phenotypes as a result of different genotypes in the gene encoding the protein responsible for the disease. D. A and B E. B and C

C. Some diseases demonstrate an array of disease phenotypes as a result of different genotypes in the gene encoding the protein responsible for the disease.

41. Which of the following is false? A. During mitosis chromosomal duplication and cell division result in two daughter cells receiving the same number and kinds of chromosomes as a parent cell (i.e., diploid -> diploid). B. Meiosis is a process of chromosomal reduction and cell division that ultimately results in the formation of four daughter cells, each with half as many chromosomes as the parent cell (i.e. diploid -> haploid). C. All four daughter cells that are formed during meiosis have exactly the same number and kind of chromosomes. D. A and B E. B and C

C. All four daughter cells that are formed during meiosis have exactly the same number and kind of chromosomes.

42. The two main parts of the cell cycle are interphase and cell division. True False

true

43. Which of the following is false? A. Congenital diseases are always inherited. B. Intrauterine injury can result in a congenital disease. C. A congenital disease may not be evident at birth. D. A and B E. A and C

A. Congenital diseases are always inherited.

Session 3 Flashcards

(94 cards)