week 9

Question 1

1) The basic structural and functional unit of the human body is A) protein. B) the cell. C) tissue. D) the organ. E) the organ system.

Answer 1

1) The basic structural and functional unit of the human body is A) protein. B) the cell. * C) tissue. D) the organ. E) the organ system.

Question 2

2) Which of the following terms is not used to define the structure that separates the contents of a human cell from its surrounding medium? A) cell wall B) cell membrane C) plasma membrane D) plasmalemma E) both A and D

Answer 2

2) Which of the following terms is not used to define the structure that separates the contents of a human cell from its surrounding medium? A) cell wall * B) cell membrane C) plasma membrane D) plasmalemma E) both A and D

Question 3

3) The cell membrane includes A) integral proteins. B) glycolipids. C) phospholipids. D) all of the above E) A and C only

Answer 3

3) The cell membrane includes A) integral proteins. B) glycolipids. C) phospholipids. D) all of the above * E) A and C only

Question 4

4) Extracellular fluid serves as A) a storage area. B) a reserve area. C) a component of the phospholipid bilayer. D) a transport medium. E) a transport medium with large storage capacity.

Answer 4

4) Extracellular fluid serves as A) a storage area. B) a reserve area. C) a component of the phospholipid bilayer. D) a transport medium. * E) a transport medium with large storage capacity.

Question 5

5) The terminal web is best described as A) filaments of actin forming a layer just inside the cell membrane at the exposed cell surface. B) filaments of cytoskeleton forming a layer just inside the cell membrane at the exposed cell surface. C) filaments of actin forming a layer just inside the cell membrane at the unexposed cell surface. D) filaments of cytoskeleton forming a layer just inside the cell membrane at the unexposed cell surface. E) cytosol that has hardened.

Answer 5

5) The terminal web is best described as A) filaments of actin forming a layer just inside the cell membrane at the exposed cell surface. * B) filaments of cytoskeleton forming a layer just inside the cell membrane at the exposed cell surface. C) filaments of actin forming a layer just inside the cell membrane at the unexposed cell surface. D) filaments of cytoskeleton forming a layer just inside the cell membrane at the unexposed cell surface. E) cytosol that has hardened.

Question 6

6) In the mitochondrion, folds are to cristae as the contained fluid is to A) actin. B) microvilli. C) cytosol. D) basal body. E) matrix.

Answer 6

6) In the mitochondrion, folds are to cristae as the contained fluid is to A) actin. B) microvilli. C) cytosol. D) basal body. E) matrix. *

Question 7

7) Vesicles containing enzymes that neutralize toxins such as alcohol are A) lysosomes. B) peroxisomes. C) centrosomes. D) endosomes. E) toxisomes.

Answer 7

7) Vesicles containing enzymes that neutralize toxins such as alcohol are A) lysosomes. B) peroxisomes. * C) centrosomes. D) endosomes. E) toxisomes.

Question 8

8) When activated, lysosomes function in A) formation of new cell membranes. B) synthesis of proteins. C) digestion of foreign material. D) synthesis of lipids. E) cell division.

Answer 8

8) When activated, lysosomes function in A) formation of new cell membranes. B) synthesis of proteins. C) digestion of foreign material. * D) synthesis of lipids. E) cell division.

Question 9

9) The control center for cellular operations is the A) nucleus. B) mitochondria. C) Golgi apparatus. D) endoplasmic reticulum. E) ribosome.

Answer 9

9) The control center for cellular operations is the A) nucleus. * B) mitochondria. C) Golgi apparatus. D) endoplasmic reticulum. E) ribosome.

Question 10

10) The complex structures of DNA and protein found in the cell nucleus are A) nucleoplasm. B) chromosomes. C) histones. D) nucleases. E) mitochondria.

Answer 10

10) The complex structures of DNA and protein found in the cell nucleus are A) nucleoplasm. B) chromosomes. * C) histones. D) nucleases. E) mitochondria.

Question 11

11) The process of forming mRNA is called A) replication. B) transcription. C) translation. D) ribolation. E) auscultation.

Answer 11

11) The process of forming mRNA is called A) replication. B) transcription. * C) translation. D) ribolation. E) auscultation.

Question 12

12) The process of protein formation is called A) replication. B) transcription. C) translation. D) mitosis. E) auscultation.

Answer 12

12) The process of protein formation is called A) replication. B) transcription. C) translation. * D) mitosis. E) auscultation.

Question 13

13) The movement of oxygen from an area of high concentration to an area of low concentration is an example of A) osmosis. B) active transport. C) diffusion. D) facilitated transport. E) filtration.

Answer 13

13) The movement of oxygen from an area of high concentration to an area of low concentration is an example of A) osmosis. B) active transport. C) diffusion. * D) facilitated transport. E) filtration.

Question 14

14) Water molecules and small ions enter a cell through A) channels in some integral proteins. B) peripheral proteins. C) lipid channels. D) peripheral carbohydrates. E) small holes in the lipid layer of the membrane.

Answer 14

14) Water molecules and small ions enter a cell through A) channels in some integral proteins. * B) peripheral proteins. C) lipid channels. D) peripheral carbohydrates. E) small holes in the lipid layer of the membrane.

Question 15

15) A solution that contains a lower solute concentration than the cytoplasm of a cell is called A) merotonic. B) hypertonic. C) isotonic. D) hypotonic. E) homotonic.

Answer 15

15) A solution that contains a lower solute concentration than the cytoplasm of a cell is called A) merotonic. B) hypertonic. C) isotonic. D) hypotonic. * E) homotonic.

Question 16

16) Crenation occurs when a blood cell is placed in a(n) _____ solution. A) isotonic B) hypertonic C) hypotonic D) merotonic E) homotonic

Answer 16

16) Crenation occurs when a blood cell is placed in a(n) _____ solution. A) isotonic B) hypertonic * C) hypotonic D) merotonic E) homotonic

Question 17

17) The process by which molecules such as glucose are moved into cells along their concentration gradient with the help of membrane-bound carrier proteins is called A) osmosis. B) facilitated diffusion. C) active transport. D) endocytosis. E) exocytosis.

Answer 17

17) The process by which molecules such as glucose are moved into cells along their concentration gradient with the help of membrane-bound carrier proteins is called A) osmosis. B) facilitated diffusion. * C) active transport. D) endocytosis. E) exocytosis.

Question 18

18) Diffusion of a substance across the cell membrane is influenced by all of the following, except A) its ability to dissolve in water. B) the size of the membrane channel. C) the charge on the ion or molecule. D) the charge of the membrane. E) its solubility in the lipid membrane.

Answer 18

18) Diffusion of a substance across the cell membrane is influenced by all of the following, except A) its ability to dissolve in water. * B) the size of the membrane channel. C) the charge on the ion or molecule. D) the charge of the membrane. E) its solubility in the lipid membrane.

Question 19

19) Facilitated diffusion differs from ordinary diffusion in that A) facilitated diffusion expends no ATP. B) facilitated diffusion moves molecules from an area of their higher concentration to their lower concentration. C) the rate of molecular movement is limited by the number of available carrier molecules. D) facilitated diffusion never eliminates the concentration gradient. E) the rate of molecular movement is not limited by the number of available carrier molecules

Answer 19

19) Facilitated diffusion differs from ordinary diffusion in that A) facilitated diffusion expends no ATP. B) facilitated diffusion moves molecules from an area of their higher concentration to their lower concentration. C) the rate of molecular movement is limited by the number of available carrier molecules. * D) facilitated diffusion never eliminates the concentration gradient. E) the rate of molecular movement is not limited by the number of available carrier molecules

Question 20

20) A process that requires cellular energy to move a substance against its concentration gradient is called A) active transport. B) passive transport. C) facilitated transport. D) osmosis. E) diffusion.

Answer 20

20) A process that requires cellular energy to move a substance against its concentration gradient is called A) active transport. * B) passive transport. C) facilitated transport. D) osmosis. E) diffusion.

Question 21

21) The packaging of extracellular materials in a vesicle at the cell surface for importation into the cell is called A) osmosis. B) active transport. C) facilitated transport. D) endocytosis. E) an ion exchange pump.

Answer 21

21) The packaging of extracellular materials in a vesicle at the cell surface for importation into the cell is called A) osmosis. B) active transport. C) facilitated transport. D) endocytosis. * E) an ion exchange pump.

Question 22

22) The principal cations in our body fluids are _____ and _____. A) sodium; potassium B) calcium; magnesium C) sodium; magnesium D) chloride; potassium E) sodium; chloride

Answer 22

22) The principal cations in our body fluids are _____ and _____. A) sodium; potassium * B) calcium; magnesium C) sodium; magnesium D) chloride; potassium E) sodium; chloride

Question 23

23) In order to maintain cellular homeostasis, an important exchange pump within the cell membrane ejects _____ ions from the cell and imports _____ ions. A) potassium; calcium B) sodium; calcium C) potassium; sodium D) sodium; potassium E) calcium; sodium

Answer 23

23) In order to maintain cellular homeostasis, an important exchange pump within the cell membrane ejects _____ ions from the cell and imports _____ ions. A) potassium; calcium B) sodium; calcium C) potassium; sodium D) sodium; potassium * E) calcium; sodium

Question 24

24) When describing a cell’s membrane potential, the cell interior is A) more positively charged than the exterior. B) more negatively charged than the exterior. C) electrically neutral. D) continuously reversing its electrical charge. E) positively charged whenever the sodium–potassium pump is active.

Answer 24

24) When describing a cell’s membrane potential, the cell interior is A) more positively charged than the exterior. B) more negatively charged than the exterior. * C) electrically neutral. D) continuously reversing its electrical charge. E) positively charged whenever the sodium–potassium pump is active.

Question 25

25) Endocytosis is A) a method for transporting substances across the cell membrane. B) a method for metabolizing within the cytosol. C) a form of anabolism. D) a manner in which lysosomes are formed. E) a method for synthesizing products.

Answer 25

25) Endocytosis is A) a method for transporting substances across the cell membrane. * B) a method for metabolizing within the cytosol. C) a form of anabolism. D) a manner in which lysosomes are formed. E) a method for synthesizing products.

Question 26

26) Peroxisomes A) contain enzymes that break down hydrogen peroxide. B) absorb and break down fatty acids, generating hydrogen peroxide in the process. C) are the same organelle as lysosomes. D) A and B E) none of the above

Answer 26

26) Peroxisomes A) contain enzymes that break down hydrogen peroxide. B) absorb and break down fatty acids, generating hydrogen peroxide in the process. C) are the same organelle as lysosomes. D) A and B * E) none of the above

Question 27

27) A mature red blood cell lacks a nucleus. Thus, it A) can repair itself rather readily. B) is malformed. C) is normal, but its function will be impaired. D) will be a long-lived cell. E) cannot repair itself and will disintegrate within a few months.

Answer 27

27) A mature red blood cell lacks a nucleus. Thus, it A) can repair itself rather readily. B) is malformed. C) is normal, but its function will be impaired. D) will be a long-lived cell. E) cannot repair itself and will disintegrate within a few months. *

Question 28

28) Chromosomes consist of _____ and _____. A) RNA; carbohydrates B) DNA; lipids C) DNA; proteins D) water; RNA E) RNA; proteins

Answer 28

28) Chromosomes consist of _____ and _____. A) RNA; carbohydrates B) DNA; lipids C) DNA; proteins * D) water; RNA E) RNA; proteins

Question 29

29) In the course of a semester, items began disappearing from the A&P lab. Students claimed that they saw nobody remove any items from the classroom. The instructor decided to investigate this phenomenon. Which of the following could have been used to identify the culprit using DNA fingerprinting? A) skin scrapings. B) hair samples. C) photo identification. D) indirect observation. E) A and B

Answer 29

29) In the course of a semester, items began disappearing from the A&P lab. Students claimed that they saw nobody remove any items from the classroom. The instructor decided to investigate this phenomenon. Which of the following could have been used to identify the culprit using DNA fingerprinting? A) skin scrapings. B) hair samples. C) photo identification. D) indirect observation. E) A and B *

Question 30

30) The functional units of DNA are A) chromosomes. B) genes. C) proteins. D) codons. E) RNA.

Answer 30

30) The functional units of DNA are A) chromosomes. B) genes. * C) proteins. D) codons. E) RNA.

Question 31

31) Specific proteins are manufactured through the interaction of _____ and _____. A) multiple enzymes; three types of RNA B) multiple enzymes; two types of RNA C) multiple carbohydrates; three types of DNA D) multiple proteins; three types of DNA E) multiple enzymes; three types of DNA

Answer 31

31) Specific proteins are manufactured through the interaction of _____ and _____. A) multiple enzymes; three types of RNA * B) multiple enzymes; two types of RNA C) multiple carbohydrates; three types of DNA D) multiple proteins; three types of DNA E) multiple enzymes; three types of DNA

Question 32

32) The type of transport process that always requires energy or an active process is termed A) diffusion. B) carrier-mediated transport. C) vesicular transport. D) freely permeable. E) impermeable.

Answer 32

32) The type of transport process that always requires energy or an active process is termed A) diffusion. B) carrier-mediated transport. C) vesicular transport. * D) freely permeable. E) impermeable.

Question 33

33) Cell shrinkage is to _____ as cell bursting is to _____. A) crenation; lysis B) lysis; crenation C) hypotonic; isotonic D) isotonic; hypotonic E) isotonic; hypertonic

Answer 33

33) Cell shrinkage is to _____ as cell bursting is to _____. A) crenation; lysis * B) lysis; crenation C) hypotonic; isotonic D) isotonic; hypotonic E) isotonic; hypertonic

Question 34

34) Two types of vesicular transport include A) endocytosis and indocytosis. B) endocytosis and exocytosis. C) exocytosis and indocytosis. D) pinocytosis and active transport. E) diffusion and active transport.

Answer 34

34) Two types of vesicular transport include A) endocytosis and indocytosis. B) endocytosis and exocytosis. * C) exocytosis and indocytosis. D) pinocytosis and active transport. E) diffusion and active transport.

Question 35

35) A unit in messenger RNA consisting of a set of three consecutive nucleotides is termed a/n A) amino acid. B) tRNA. C) rRNA. D) codon. E) pore.

Answer 35

35) A unit in messenger RNA consisting of a set of three consecutive nucleotides is termed a/n A) amino acid. B) tRNA. C) rRNA. D) codon. * E) pore.

Question 36

36) A carbohydrate that cannot cross cell membranes that is commonly administered to patients suffering blood loss is A) saline solution. B) salt solution. C) glucose. D) isotonic saline. E) dextran.

Answer 36

36) A carbohydrate that cannot cross cell membranes that is commonly administered to patients suffering blood loss is A) saline solution. B) salt solution. C) glucose. D) isotonic saline. E) dextran. *

Question 37

37) What is the first part of the cell that is affected when the pH of extracellular fluid changes? A) nucleolus B) cilia C) the cytosol D) cell membrane E) cytoskeleton

Answer 37

37) What is the first part of the cell that is affected when the pH of extracellular fluid changes? A) nucleolus B) cilia C) the cytosol D) cell membrane * E) cytoskeleton

Question 38

38) Which endoplasmic reticulum modifies and packages newly synthesized proteins? A) the ribosomal reticulum B) the proteosomes reticulum C) the raised reticulum D) the smooth reticulum E) the rough reticulum

Answer 38

38) Which endoplasmic reticulum modifies and packages newly synthesized proteins? A) the ribosomal reticulum B) the proteosomes reticulum C) the raised reticulum D) the smooth reticulum E) the rough reticulum *

Question 39

39) Inside the cell, membrane proteins are bound to the A) cytoplasm. B) cytoskeleton. C) protein fibers. D) phospholipid bilayer. E) cell membrane.

Answer 39

39) Inside the cell, membrane proteins are bound to the A) cytoplasm. B) cytoskeleton. * C) protein fibers. D) phospholipid bilayer. E) cell membrane.

Question 40

40) The endoplasmic reticulum is responsible for A) drug and toxin neutralization. B) protein, carbohydrate, and lipid synthesis. C) storage of synthesized molecules. D) all of the above E) both A and C

Answer 40

40) The endoplasmic reticulum is responsible for A) drug and toxin neutralization. B) protein, carbohydrate, and lipid synthesis. C) storage of synthesized molecules. D) all of the above * E) both A and C

Question 41

41) A substance containing atoms of different elements that are bonded together is called a(n) A) molecule. B) compound. C) mixture. D) isotope. E) solution.

Answer 41

41) A substance containing atoms of different elements that are bonded together is called a(n) A) molecule. B) compound. * C) mixture. D) isotope. E) solution.

Question 42

42) Special catalytic molecules called _____ control chemical reactions in the human body. A) enzymes B) cytozymes C) cofactors D) activators E) cytochormes

Answer 42

42) Special catalytic molecules called _____ control chemical reactions in the human body. A) enzymes * B) cytozymes C) cofactors D) activators E) cytochormes

Question 43

43) All organic compounds in the human body contain all of the following, except A) hydrogen. B) oxygen. C) carbon. D) calcium. E) both A and D

Answer 43

43) All organic compounds in the human body contain all of the following, except A) hydrogen. B) oxygen. C) carbon. D) calcium. * E) both A and D

Question 44

44) Which of the following is not a function of protein? A) support B) transport C) metabolic regulation D) storage of genetic information E) movement

Answer 44

44) Which of the following is not a function of protein? A) support B) transport C) metabolic regulation D) storage of genetic information * E) movement

Question 45

45) Haemolysis may occur when a blood cell is placed into A) isotonic solution. B) hypertonic solution. C) hypotonic solution. D) merotonic solution. E) homotonic.

Answer 45

45) Haemolysis may occur when a blood cell is placed into A) isotonic solution. B) hypertonic solution. C) hypotonic solution. * D) merotonic solution. E) homotonic.

Question 46

46) If a cell lacked the enzyme DNA polymerase, it could not A) form protein. B) form complementary sequences of DNA. C) link pieces of DNA together. D) form spindle fibers. E) form a new nuclear membrane during telophase.

Answer 46

46) If a cell lacked the enzyme DNA polymerase, it could not A) form protein. B) form complementary sequences of DNA. * C) link pieces of DNA together. D) form spindle fibers. E) form a new nuclear membrane during telophase.

Question 47

47) Compared to the extracellular fluid, cytosol contains A) a higher concentration of sodium ion. B) a relatively high concentration of dissolved proteins. C) relatively low supplies of carbohydrates. D) relatively few amino acids. E) no lipids.

Answer 47

47) Compared to the extracellular fluid, cytosol contains A) a higher concentration of sodium ion. B) a relatively high concentration of dissolved proteins. * C) relatively low supplies of carbohydrates. D) relatively few amino acids. E) no lipids.

Question 48

48) If an animal cell lacked centrioles, it would not be able to A) move. B) synthesize proteins. C) produce DNA. D) metabolize sugars. E) divide.

Answer 48

48) If an animal cell lacked centrioles, it would not be able to A) move. B) synthesize proteins. C) produce DNA. D) metabolize sugars. E) divide. *

Question 49

49) Each of the following statements concerning mitochondria is true, except one. Identify the exception. A) The mitochondrial cristae increase the inner surface area of the organelle. B) The matrix of the mitochondria contains metabolic enzymes involved in energy production. C) Respiratory enzymes are attached to the surface of the cristae. D) The mitochondria contain no DNA or RNA. E) The mitochondria produce most of a cell’s ATP.

Answer 49

49) Each of the following statements concerning mitochondria is true, except one. Identify the exception. A) The mitochondrial cristae increase the inner surface area of the organelle. B) The matrix of the mitochondria contains metabolic enzymes involved in energy production. C) Respiratory enzymes are attached to the surface of the cristae. D) The mitochondria contain no DNA or RNA. * E) The mitochondria produce most of a cell’s ATP.

Question 50

50) Each of the following is a function of smooth endoplasmic reticulum, except A) removal and storage of calcium ions. B) modification of protein products. C) synthesis of steroid hormones. D) synthesis of triglycerides in liver cells. E) detoxification of drugs in liver cells.

Answer 50

50) Each of the following is a function of smooth endoplasmic reticulum, except A) removal and storage of calcium ions. B) modification of protein products. * C) synthesis of steroid hormones. D) synthesis of triglycerides in liver cells. E) detoxification of drugs in liver cells.

Question 51

51) Two solutions are separated by a semipermeable membrane with the same properties as a cell membrane. Solution A is 5 percent glucose and solution B is 10 percent glucose. Under these circumstances, which of the following would most likely occur? A) Water will move from solution A to solution B. B) Water will move from solution B to solution A. C) Glucose will move from solution A to solution B. D) Glucose will move from solution B to solution A. E) At equilibrium the concentration of glucose will be higher in solution B.

Answer 51

51) Two solutions are separated by a semipermeable membrane with the same properties as a cell membrane. Solution A is 5 percent glucose and solution B is 10 percent glucose. Under these circumstances, which of the following would most likely occur? A) Water will move from solution A to solution B. * B) Water will move from solution B to solution A. C) Glucose will move from solution A to solution B. D) Glucose will move from solution B to solution A. E) At equilibrium the concentration of glucose will be higher in solution B.

Question 52

52) If the amount of sodium ion in blood plasma increases, which of the following would initially occur? A) The blood osmotic pressure will increase. B) The blood osmotic pressure will decrease. C) The blood osmotic pressure will stay the same. D) The blood hydrostatic pressure will increase. E) The blood hydrostatic pressure will decrease.

Answer 52

52) If the amount of sodium ion in blood plasma increases, which of the following would initially occur? A) The blood osmotic pressure will increase. * B) The blood osmotic pressure will decrease. C) The blood osmotic pressure will stay the same. D) The blood hydrostatic pressure will increase. E) The blood hydrostatic pressure will decrease.

Question 53

53) If the concentration of sodium ions in the fluid surrounding cells decreases and the concentration of other solutes remains constant, A) the cells will shrink. B) the cells will swell. C) the fluid outside of the cells will become isotonic. D) the fluid outside of the cells will become hypertonic. E) the cells will not change.

Answer 53

53) If the concentration of sodium ions in the fluid surrounding cells decreases and the concentration of other solutes remains constant, A) the cells will shrink. B) the cells will swell. * C) the fluid outside of the cells will become isotonic. D) the fluid outside of the cells will become hypertonic. E) the cells will not change.

Question 54

54) The movement of a particular amino acid across the cell membrane (along its concentration gradient) is impaired when a molecule chemically similar to the amino acid is added to the extracellular fluid. The movement of the amino acid through the membrane is by A) osmosis. B) diffusion. C) facilitated diffusion. D) active transport. E) pinocytosis.

Answer 54

54) The movement of a particular amino acid across the cell membrane (along its concentration gradient) is impaired when a molecule chemically similar to the amino acid is added to the extracellular fluid. The movement of the amino acid through the membrane is by A) osmosis. B) diffusion. C) facilitated diffusion. * D) active transport. E) pinocytosis.

Question 55

55) Generally, cells with slower mitotic rates A) are stem cells. B) do not exhibit cytokinesis. C) have longer life spans. D) are reproductive cells. E) lack the enzyme DNA polymerase.

Answer 55

55) Generally, cells with slower mitotic rates A) are stem cells. B) do not exhibit cytokinesis. C) have longer life spans. * D) are reproductive cells. E) lack the enzyme DNA polymerase.

Question 56

56) ________________________form the bilayer that separates cell from environment

Answer 56

56) ________________________form the bilayer that separates cell from environment Answer: phospholipids

Question 57

57) Some ___________________________act as gates, allowing ions to cross the plasma membrane

Answer 57

57) Some ___________________________act as gates, allowing ions to cross the plasma membrane Answer: integral proteins

Question 58

58) All cell contents between plasma membrane and nucleus is known as __________________

Answer 58

58) All cell contents between plasma membrane and nucleus is known as __________________ Answer: cytoplasm

Question 59

59) The transport mechanism allowing ingestion of solid particles by white blood cells is called ____________________

Answer 59

59) The transport mechanism allowing ingestion of solid particles by white blood cells is called ______________________ Answer: phagocytosis

Question 60

60) The fluid portion of the cytoplasm is the ___________

Answer 60

60) The fluid portion of the cytoplasm is the _________________________. Answer: cytosol

Question 61

61) The _________________________ is the boundary between the cell and its environment.

Answer 61

61) The _________________________ is the boundary between the cell and its environment. Answer: plasma membrane

Question 62

62) The __________________ have polar carbohydrate heads and nonpolar hydrocarbon tails; they are found only in the outer layer of the plasma membrane.

Answer 62

62) The __________________ have polar carbohydrate heads and nonpolar hydrocarbon tails; they are found only in the outer layer of the plasma membrane. Answer: glycolipids

Question 63

63) Membrane ________________ have diverse functions including serving as ion channels and cell-identity markers.

Answer 63

63) Membrane ________________ have diverse functions including serving as ion channels and cell-identity markers. Answer: proteins

Question 64

64) The property of membranes that allows some substances to pass more readily than others is called _________________________

Answer 64

64) The property of membranes that allows some substances to pass more readily than others is called ______________________________. Answer: selective permeability

Question 65

65) The normal intracellular concentration of glucose is approximately 5%. An infusion containing 10% glucose would be __________________ to the cell.

Answer 65

65) The normal intracellular concentration of glucose is approximately 5%. An infusion containing 10% glucose would be __________________ to the cell. Answer: hypertonic

Question 66

66) The ____________________ is the network of microtubules, intermediate filaments and microfilaments that help support and shape the cell and help organize its contents.

Answer 66

66) The ____________________ is the network of microtubules, intermediate filaments and microfilaments that help support and shape the cell and help organize its contents. Answer: cytoskeleton

Question 67

67) _______________ are small sacs that transport materials from the endoplasmic reticulum to the Golgi complex or from the Golgi complex to other parts of the cell.

Answer 67

67) _______________ are small sacs that transport materials from the endoplasmic reticulum to the Golgi complex or from the Golgi complex to other parts of the cell. Answer: Vesicles

Question 68

68) _________________ is the self-destruction of the cell due to release of lysosomal enzymes.

Answer 68

68) _________________ is the self-destruction of the cell due to release of lysosomal enzymes. Answer: Autolysis

Question 69

69) _________________________ regulate the passage of materials in and out of the nucleus.

Answer 69

69) _________________________ regulate the passage of materials in and out of the nucleus. Answer: Nuclear pores

Question 70

70) ____ are the heredity units that provide instructions for making proteins.

Answer 70

70) ____ are the heredity units that provide instructions for making proteins. Answer: Genes

Question 71

71) _____ is the enzyme that catalyzes transcription of DNA.

Answer 71

71) _____ is the enzyme that catalyzes transcription of DNA. Answer: RNA polymerase

Question 72

72) _____ is the division of nuclear contents in somatic cells.

Answer 72

72) _____ is the division of nuclear contents in somatic cells. Answer: Mitosis

Question 73

73) ____ is the programmed death of cells that are no longer needed.

Answer 73

73) ____ is the programmed death of cells that are no longer needed. Answer: Apoptosis

Question 74

74) Discuss the fluid mosaic model of plasma membrane structure. (5 marks)

Answer 74

Answer: Proteins “float” among phospholipids; phospholipid bilayer, with hydrophobic ends facing each other and hydrophilic ends facing either ECF or ICF; phospholipids can move sideways within layer; glycolipids (cellular identity markers) face ECF; cholesterol molecules (for stability) among phospholipids of both layers of the bilayer; integral proteins (channels, transporters, etc.) extend across phospholipid bilayer; peripheral proteins (enzymes, cytoskeleton anchors, etc.) loosely attached to either the inner or outer surface of the membrane.

Question 75

75) Name and describe the four phases of mitosis in sequence.

Answer 75

Answer: 1. Prophase: chromatin fibers shorten and coil into chromosomes; nucleoli and nuclear envelope disappear; centrosomes with centrioles move to opposite poles of cell; mitotic spindle appears 2. Metaphase: centromeres of chromatid pairs line up on metaphase plate of cell 3. Anaphase: centromeres divide; identical sets of chromosomes move to opposite poles of cell 4. Telophase: nuclear envelope reappears to enclose chromosomes; chromosomes revert to chromatin; nucleoli reappear; mitotic spindle disappears.

Question 76

76) What is the ‘cell theory’?

Answer 76

2) Activity of the organism depends on individual and collective activity of cells; 3) Biochemical activities of cells are dictated by subcellular structure; 4) Continuity of life has a cellular basis