Mid-Sem exam HUBS1403

b) Molecules, cells, tissues, organs

1. Which of the following is the correct order of organisation from lowest to highest
a) Cellular, organ, tissue, organism
b) Molecules, cells, tissues, organs
c) Organs, tissues, cells, molecules
d) Organ systems, cells, tissues
e) Cells, organs, organ systems, organelles

d) The maintenance of a relatively stable internal environment within narrow limits

2. Define homeostasis
a) The process by which a protein is formed
b) The maintenance of an exact fixed level of conditions
c) Ensuring the outside environment matches that within the organism
d) The maintenance of a relatively stable internal environment within narrow limits
e) Organelle responsible for energy production

c) ECF

3. Most water in the body is found in the:
a) stomach
b) brain
c) ECF
d) ICF
e) Blood

b) platelets at a blood clot attract more platelets

4. Which of the following is an example of a positive feedback mechanism
a) temperature decreases so shivering occurs in increase temperature
b) platelets at a blood clot attract more platelets
c) temperature increase leads to sweating to decrease temperature
d) both A and B
e) Both B and C

e) Both A and B

5. A negative feedback system:
a) Provides longterm control of homeostasis
b) Reverses the effects of the original stimulus
c) Lowers body temperature
d) Lowers heartrate
e) Both A and B

a) All matter is composed of them. Cannot be split into smaller substances

6. What is an element?
a) All matter is composed of them. Cannot be split into smaller substances
b) 2 or more types of atoms combined in a fixed ratio
c) The smallest particle known to exist
d) Found in the nucleus with a charge of +1
e) Covalent bonded atoms of the same type

a) different forms of an element, varying in number of neutrons

7. What is an isotope?
a) different forms of an element, varying in number of neutrons
b) 2 or more elements combined in a fixed ratio
c) Multiple copies of a cell
d) A substance that is always radioactive
e) Atoms of the same type with different numbers of protons

b) Is composed of electrons surrounding the nucleus

8. An electron shell:
a) Is found in the nucleus of an atom
b) Is composed of electrons surrounding the nucleus
c) Is a husk protecting vulnerable electrons inside
d) Contains both electrons and neutrons
e) Has a positive charge

e) ii and iv are true

9. Consider the following statements regarding ions:
i) Are electrically neutral
ii) Have gained or lost electrons
iii) Anions have a positive charge
iv) Cations have a positive charge
v) Have equal numbers of protons and electrons
a) All are true
b) All are false
c) i and ii are true
d) I and v are true
e) ii and iv are true

d) i, iv and v are true

10. Which of the following statements are true:
i) Organic compounds contain carbon
ii) Inorganic compounds never contain carbon
iii) Inorganic compounds are of biological origin
iv) Inorganic compounds are important for life
v) Carbohydrates are organic
a) All are true
b) All are false
c) i, ii, iv and v are true
d) i, iv and v are true
e) Ii, iii and v are true

a) Covalent

11. Which types of bonds are strongest between atoms?
a) Covalent
b) Ionic
c) Hydrogen
d) Intermolecular
e) Metallic

a) All are true

12. Consider the following statements:
i) Covalent bonds involve sharing of electrons
ii) Polar covalent bonds have unequal sharing
iii) Ionic bonds involve electron transfer
iv) Covalent bonds may be single, double or triple
v) Hydrogen bonds form between adjacent molecules rather than forming molecular bonds
a) All are true
b) All are false
c) i, ii and iii are true
d) Only v is true
e) iv and v are true

e) All of the above

13. Water is used for:
a) As a solvent
b) In reactions
c) To maintain thermostability
d) As a lubricant
e) All of the above

c) A soluble inorganic molecule that will produce ions to conduct electrical current in solution

14. What is an electrolyte?
a) Organic molecules in solution
b) Polar, inorganic molecules
c) A soluble inorganic molecule that will produce ions to conduct electrical current in solution
d) A highly reactive compound necessary for maintaining pH
e) Both B and D

a) Incorrect levels of H+ can damage cells, affect enzyme activity and break chemical bonds

15. Why is it necessary to regulate pH levels?
a) Incorrect levels of H+ can damage cells, affect enzyme activity and break chemical bonds
b) pH molecules will react with oxygen in the blood
c) pH levels that are too high makes the blood too acidic
d) H+ concentration too high makes the blood too alkaline
e) Both C and D

c) All chemical reactions in the body

16. What is metabolism?
a) All anabolic reactions in the body
b) All catabolic reactions in the body
c) All chemical reactions in the body
d) Anabolic reactions and catabolic reactions
e) The process by which the body maintains a relatively stable internal environment

a) Catabolism

17. Digestion of sugars to release energy is an example of:
a) Catabolism
b) Anabolism
c) Substitution reaction
d) Proteolysis
e) Immune function

b) Anabolism

18. Polymerisation of amino acids to form a protein is an example of
a) Catabolism
b) Anabolism
c) Substitution reaction
d) Proteolysis
e) Immune function

d) Statements iii, iv and v are true

19. Consider the following statements about enzymes:
i) Enzymes are used up in reactions
ii) Enzymes raise the activation energy
iii) Enzymes increase the rate of reactions
iv) Enzymes can be saturated
v) Enzymes are specific for one type of reaction
a) All statements are true
b) All statements are false
c) Only statement i is false
d) Statements iii, iv and v are true
e) Statements i, ii and iii are true

e) Both A and B

20. Carbohydrates are used for:
a) Cell wall recognition
b) Energy
c) Storage of large amounts of energy
d) Insulation
e) Both A and B

d) ii, iii and v are true

21. Consider the following statements about lipids:
i) Dissolve in water
ii) Contain more energy than carbohydrates
iii) Are important for energy storage
iv) Have more Oxygen than carbohydrates
v) Require special transport mechanisms in the blood
a) All are true
b) All are false
c) I, iii and iv are true
d) Ii, iii and v are true
e) Only i is false

c) Saturated fatty acid

22. A compound in the body is described as "a long hydrocarbon chain, containing all single bonds, with a carboxylic acid as the head". This is most likely a:
a) Protein
b) Unsaturated fatty acid
c) Saturated fatty acid
d) phospholipid
e) glycolipid

b) leukotrienes

23. arachidonic acid is used to produce
a) fatty acids
b) leukotrienes
c) proteins
d) nucleic acids
e) cytoplasm

b) coordinating local actions

24. prostaglandins are used for:
a) energy storage
b) coordinating local actions
c) as a neurotransmitter
d) insulation
e) as a structural component of plasma membranes

e) Statements iii and v are false

25. With respect to triglycerides:
i) They are composed of glycerol and 3 chains of fatty acids
ii) Are used for insulation
iii) Are primarily used for plasma membrane structure
iv) Are used for energy storage
v) Have fatty acids strung together in a long chain
a) All statements are true
b) All statements are false
c) Only statement v is false
d) Only statement iii is false
e) Statements iii and v are false

d) Steroids have a 5 carbon ring with 2 carbon tails coming off the ring

26. Which of the following is incorrect:
a) Steroids are used in sex hormones
b) Steroids are used in cell membranes
c) Cholesterol is a steroid
d) Steroids have a 5 carbon ring with 2 carbon tails coming off the ring
e) Steroids are used in bile salts

c) Lipoproteins transport fatty acids and cholesterol in the blood

27. Which of the following statements is correct?
a) Lipoproteins have a polar tail and non-polar head
b) Lipoproteins consist of glucose and lipids
c) Lipoproteins transport fatty acids and cholesterol in the blood
d) Lipoproteins have a main function of energy storage
e) Lipoproteins are involved in movement of the body

a) Polar phosphate head connected to a diglyceride tail

28. Which of the following best describes the structure of a phospholipid?
a) Polar phosphate head connected to a diglyceride tail
b) Phosphate head connected to 3 fatty acids
c) Protein capsule surrounding a lipid
d) A complex 4 ring structure
e) A 5 carbon ring with 2 carbon chains coming off it

a) Transport fatty acids and cholesterol in the blood

29. The function of lipoproteins is to:
a) Transport fatty acids and cholesterol in the blood
b) Transport prostaglandins and leukotrienes in the blood
c) Remove starch from the blood
d) Increase heart rate
e) Carry electrolytes in a complex

c) Phospholipid

30. Which class of lipid plays an important role in forming cell membranes?
a) Prostaglandin
b) Fatty acids
c) Phospholipid
d) Lipoprotein
e) Both C and D

d) Statements i, iii and iv are true

31. Consider the following statements concerning proteins:
i) Proteins are the most abundant organic component in the body
ii) Proteins account for 50% of body mass
iii) Proteins are made from polypeptide chains
iv) Polypeptide chains are formed from amino acids
v) Amino acids are non-polar
a) All statements are true
b) All statements are false
c) Statement ii is false
d) Statements i, iii and iv are true
e) Statement v is false

e) Used as the main energy source of the body

32. Which of the following is not a function of a protein?
a) Support and structure
b) Movement of the whole body
c) Movement of individual cells
d) Transport of substances around the body
e) Used as the main energy source of the body

e) All of the above

33. Proteins have a role in:
a) Metabolic regulation
b) Buffering
c) Defence
d) Hormonal regulation
e) All of the above

b) Different amino acids differ only in the composition of their side chain

34. Which of the following statements about amino acids is correct?
a) Amino acids contain have only acidic groups
b) Different amino acids differ only in the composition of their side chain
c) Amino acids never carry a charge
d) Amino acids are the foundation of lipid synthesis
e) All amino acids may be synthesised by the body

c) Peptide bonds

35. Amino acids are strung together in a chain by:
a) Protein connections
b) Desmosomes
c) Peptide bonds
d) Covalent bonds
e) Ionic bonds

a) The sequence of amino acids

36. The primary structure of a protein refers to:
a) The sequence of amino acids
b) Complex coiling and folding to produce the final shape of the protein
c) The combination of 2 subunits to form the final protein
d) Formation of localised structures due to bonding between different parts of the chain
e) A collection of secondary structures to form motifs such as zinc fingers

d) Formation of localised structures due to bonding between different parts of the chain

37. The secondary structure of a protein refers to:
a) The sequence of amino acids
b) Complex coiling and folding to produce the final shape of the protein
c) The combination of 2 subunits to form the final protein
d) Formation of localised structures due to bonding between different parts of the chain
e) A collection of secondary structures to form motifs such as zinc fingers

b) Complex coiling and folding to produce the final shape of the protein

38. The tertiary structure of a protein refers to:
a) The sequence of amino acids
b) Complex coiling and folding to produce the final shape of the protein
c) The combination of 2 subunits to form the final protein
d) Formation of localised structures due to bonding between different parts of the chain
e) A collection of secondary structures to form motifs such as zinc fingers

c) The combination of 2 subunits to form the final protein

39. The quaternary structure of a protein refers to:
a) The sequence of amino acids
b) Complex coiling and folding to produce the final shape of the protein
c) The combination of 2 subunits to form the final protein
d) Formation of localised structures due to bonding between different parts of the chain
e) A collection of secondary structures to form motifs such as zinc fingers

d) Fibrous proteins are generally readily soluble

40. Which of the following statements is INCORRECT?
a) Fibrous proteins generally have structural roles
b) Globular proteins only function when in solution
c) Examples of globular proteins include enzymes
d) Fibrous proteins are generally readily soluble
e) Fibrous proteins are generally found as extended sheets or strands

c) Statements i, iii and iv are true

41. Consider the following statements regarding enzymes:
i) Enzymes react with substrates
ii) Enzymes are used up in the reactions they are involved in
iii) Substrates must bind to an enzyme's active site
iv) Enzymes are biological catalysts
v) Enzymes are permanently active
a) All statements are true
b) Statement ii is false
c) Statements i, iii and iv are true
d) Statement ii and iv are false
e) All statements are false

c) DNA contains the nitrogenous base uracil instead of thymine in RNA

42. Which of the following is not a difference between DNA and RNA?
a) DNA is double stranded while RNA is single
b) DNA uses a deoxyribose sugar while RNA has a ribose sugar
c) DNA contains the nitrogenous base uracil instead of thymine in RNA
d) DNA remains in the nucleus while RNA may move in and out of the nucleus
e) DNA is found in linear chromosomes, RNA may be found as mRNA,tRNA or rRNA

e) All statements are correct

43. Which of the following is incorrect regarding DNA structure?
a) Each nucleotide contains a sugar, a phosphate group and a nitrogenous base
b) Two of the nitrogenous bases are pyrimidines and 2 are purines
c) The sugar is the pentose sugar deoxyribose
d) The two strands combine and entwine to form a double helix structure, stabilised by hydrogen bonds
e) All statements are correct

d) Adenine bonds to thymine and uracil, cytosine bonds to guanine

44. With regards to nitrogenous base pairing:
a) adenine only bonds to cytosine
b) Guanine bonds to adenine, cytosine bonds to thymine
c) Adenine only bonds to thymine, cytosine bonds to guanine and uracil
d) Adenine bonds to thymine and uracil, cytosine bonds to guanine
e) Thymine bonds to adenine and uracil, guanine bonds to cytosine

d) I, iii and iv are true

45. Consider the following statements regarding nucleic acids:
i) DNA encodes for protein synthesis to regulate all body functions and structure
ii) RNA is only found in the nucleus
iii) RNA is found in three forms in humans
iv) all forms of RNA are involved in protein synthesis
v) RNA is identical to DNA except for the sugar
a) all statements are true
b) v is false
c) I, ii and iii are true
d) I, iii and iv are true
e) all are false

b) all statements are true

46. Consider the following statements regarding ATP:
i) ATP is used to transfer energy around and between cells
ii) Adding phosphate groups is known as phosphorylation
iii) Formation of ATP requires enzymes
iv) Energy is released by a loss of a phosphate group to form ADP
v) while ATP is the most common, other high energy compounds exist such as GTP or UTP
a) All statements are false
b) all statements are true
c) statement v is false
d) statements I, ii and iv are true
e) statement ii is false

d) All cells have exactly the same structures

47. Which of the following is NOT a part of the cell theory?
a) Cells are the building blocks of all plants and animals
b) All cells come from pre-existing cells
c) Cells maintain homeostasis at the cellular level
d) All cells have exactly the same structures
e) Cells are the smallest units that perform all vital physiological functions

b) Directly co-ordinates intracellular reactions

48. Which of the following is NOT a function of the plasma membrane?
a) Physical isolation of the cell from the external environment
b) Directly co-ordinates intracellular reactions
c) Regulates exchange with the environment
d) Contains receptors to recognise and respond to molecules in the environment
e) Provides support for the cell and between neighbouring cells

a) A phospholipid bilayer which also contains cholesterol and protein within it

49. Which of the following best describes the structure of the plasma membrane?
a) A phospholipid bilayer which also contains cholesterol and protein within it
b) A protein capsule surrounding the cell
c) A phospholipid bilayer
d) A strong cholesterol structure linked by tight junctions and proteins
e) Contains a strong backbone of sugar and phosphate molecules

a) Peripheral proteins are bound to the inner or outer surface of the plasma membrane while integral proteins span the width of the membrane at least once

50. What is the difference between peripheral proteins and integral proteins?
a) Peripheral proteins are bound to the inner or outer surface of the plasma membrane while integral proteins span the width of the membrane at least once
b) Peripheral proteins are found near the skin while integral proteins are in the heart
c) Integral proteins are in the intracellular fluid while peripheral proteins are in the extracellular fluid
d) Integral proteins have structural roles while peripheral proteins form enzymes
e) Integral proteins are made in ribosomes attached to the endoplasmic reticulum while peripheral proteins are made in free ribosomes

b) ii and v are true

51. Consider the following statements regarding cell membrane proteins:
i) Carrier proteins are involved in facilitated diffusion of solutes while channels are used for active transport across the plasma membrane
ii) Anchoring proteins attach to both the cytoskeleton of the cell and to extracellular proteins and other cells
iii) Proteins on the cell membrane are not used in recognition of cells
iv) Enzymes are not found on the plasma membrane
v) Receptor proteins bind to ligands to cause a change in the activity of the cell
a) All statements are true
b) Ii and v are true
c) I, ii and v are true
d) Ii, iii and iv are true
e) Only iv is false

a) An extension of carbohydrate portions of plasma membrane components beyond the outer surface of the plasma membrane

52. Which of the following best describes the glycocalyx?
a) An extension of carbohydrate portions of plasma membrane components beyond the outer surface of the plasma membrane
b) Breakdown of glycogen to form glucose
c) An extension of carbohydrate portions of plasma membrane components beyond the inner surface of the plasma membrane
d) Carbohydrate components of the cytoskeleton
e) Both A and C

c) Storage of solutes from cytoplasm

53. Which of the following is not a function of the glycocalyx?
a) Lubrication of the cell
b) Recognition by immune cells
c) Storage of solutes from cytoplasm
d) Specificity of binding to ligands
e) Anchoring and locomotion

b) The viscous, semi-transparent fluid inside the plasma membrane

54. Which of the following best describes the cytosol?
a) Everything within the plasma membrane but external to the nucleus
b) The viscous, semi-transparent fluid inside the plasma membrane
c) Has a higher concentration of sodium ions than the ECF
d) Is the location where aerobic catabolism occurs to produce ATP
e) Contains DNA

e) All of the above

55. Microfilaments:
a) Are typically composed of actin
b) Anchor the cytoplasm to integral proteins in the plasma membrane
c) Act with myosin to move parts of the cell around or change the cell shape
d) Determine the consistency of the cytoplasm
e) All of the above

a) Larger than microfilaments and microtubules

56. Which of the following is not a feature of intermediate filaments?
a) Larger than microfilaments and microtubules
b) Stabilise organelle position and the position of the cell
c) Strengthen and maintain cell shape
d) May have unique functions based on cell type
e) Have specialised attachments to the plasma membrane

c) They originate from the centrosome near the nucleus

57. Which of the following statements about microtubules is correct?
a) They are the smallest component of the cytoskeleton
b) They are formed by gathering together of actin
c) They originate from the centrosome near the nucleus
d) They have a solid structure throughout
e) They play no role in cell division

a) All statements are true

58. Consider the following statements regarding microtubules:
i) They are involved in the transport of vesicles and organelles within the cell
ii) They form the spindle apparatus during cell division
iii) The centrosome contains paired centrioles
iv) Microtubules anchor major organelles to provide cell strength and rigidity
v) Microtubules may form structural components of organelles
a) All statements are true
b) Statements i, ii and iii are true
c) Statement v is false
d) Statement iv is false
e) Statement I is false

b) 9 groups of 3 microtubules, each group connected to its neighbour and forming a hollow

59. Which of the following best describes a centriole?
a) Actin filaments extending the plasma membrane into hair-like projections to increase surface area
b) 9 groups of 3 microtubules, each group connected to its neighbour and forming a hollow core. Forms the spindle apparatus
c) 9 pairs of microtubules around a central pair. Found in respiratory and reproductive tracts to move fluids and other objects
d) Dense cluster of intermediate filaments
e) Thick, dense granules

c) 9 pairs of microtubules around a central pair. Found in respiratory and reproductive tracts to move fluids and other objects

60. Which of the following best describes cilia?
a) Actin filaments extending the plasma membrane into hair-like projections to increase surface area
b) 9 groups of 3 microtubules, each group connected to its neighbour and forming a hollow core. Forms the spindle apparatus
c) 9 pairs of microtubules around a central pair. Found in respiratory and reproductive tracts to move fluids and other objects
d) Dense cluster of intermediate filaments
e) Thick, dense granules

a) Actin filaments extending the plasma membrane into hair-like

61. Which of the following best describes microvilli?
a) Actin filaments extending the plasma membrane into hair-like projections to increase surface area
b) 9 groups of 3 microtubules, each group connected to its neighbour and forming a hollow core. Forms the spindle apparatus.
c) 9 pairs of microtubules around a central pair. Found in respiratory and reproductive tracts to move fluids and other objects
d) Dense cluster of intermediate filaments
e) Thick, dense granules

a) Microfilaments
(for the purpose of HUBS1403 the answer is Microfilaments)

62. Which cytoskeleton component is the primary component?
a) Microfilaments
b) Intermediate filaments
c) Cilia
d) Microtubules
e) microvilli

b) Proteasome

63. Which organelle could be described as "a central cylinder, capped at both ends, designed to degrade proteins"?
a) Nucleolus
b) Proteasome
c) Plasma membrane
d) Golgi body
e) Lysosome

e) iii and iv are true

64. Consider the following statements regarding ribosomes:
i) Ribosomes are always attached to rough endoplasmic reticulum
ii) Ribosomes are made from DNA and RNA
iii) Ribosomes are involved in protein synthesis
iv) Ribosome occur in 2 subunits
v) The number of ribosomes in each cell is the same
a) All statements are true
b) Only v is false
c) I, ii, iii are true
d) I, iii and iv are true
e) Iii and iv are true

c) Packages molecules for exocytosis

65. Which of the following is NOT a function of the endoplasmic reticulum?
a) Synthesis of proteins, carbohydrates and lipids
b) Storage of synthesised compounds and molecules from cytosol
c) Packages molecules for exocytosis
d) Movement of materials
e) Detoxification

a) I, ii and iii are true

66. Consider the following statements about the smooth endoplasmic reticulum:
i) Smooth endoplasmic reticulum does not have ribosomes attached
ii) Is involved in synthesis of plasma membrane components
iii) Will absorb and store ions to regulate cytosol
iv) Releases lubricants to assist cell movement
v) Acts in concert with mictrotubules to move organelles
a) I, ii and iii are true
b) Iv is true
c) V is true
d) Ii and iii are true
e) All are false

e) A, B and C

67. What is the function of the golgi apparatus?
a) Package and modify secretions for exocytosis
b) Renew and modify the cell membrane
c) Package special enzymes in vesicles for use within cytosol
d) Both A and C
e) A, B and C

d) Lysosome

68. A small vesicle from the golgi apparatus, containing dangerous digestive enzymes, which protects the cell from harmful reactions is a ...
a) Peroxisome
b) Nucleosome
c) Endocytosis
d) Lysosome
e) Nucleolus

d) Both B and C

69. A peroxisome...
a) Is produced in the golgi apparatus
b) Absorbs and breaks down fatty acids
c) Breaks down H2O2 to protect cell from free radicals
d) Both B and C
e) A, B and C

e) Ii and iv are false

70. Consider the following statements regarding mitochondria:
i) Are responsible for energy production
ii) There are the same number in each cell
iii) Have an outer membrane and a highly folded inner membrane
iv) Is responsible for anaerobic metabolism
v) Is the site of the TCA cycle occurring
a) All are true
b) Ii is false
c) All are false
d) Iv is false
e) Ii and iv are false

b) Produces H atoms for use in the electron transport chain and oxidative phosphorylation

71. The TCA cycle ...
a) Is anaerobic
b) Produces H atoms for use in the electron transport chain and oxidative phosphorylation
c) Produces large amounts ATP for use by the cell
d) Uses glucose to create pyruvic acid and ATP
e) occurs in all cell types

d) The nucleus contains all the DNA and RNA of the cell

72. Which of the following statements is INCORRECT?
a) The nucleus is the largest structure of a cell
b) The nucleus communicates with cytosol through nuclear pores
c) The nuclear envelope is a double membrane surrounding the nucleus
d) The nucleus contains all the DNA and RNA of the cell
e) Both B and C

d) The fluid inside the nucleus is called the nucleoplasm

73. Which of the following statements is correct?
a) The nucleus only contains DNA and RNA
b) Nuclear pores allow movement of ions, proteins and DNA into and out of the nucleus
c) Nuclear pores cover less than 1% of the nuclear envelope
d) The fluid inside the nucleus is called the nucleoplasm
e) Regulatory proteins have no effects on transport into and out of the nucleus

d) Nucleoli contain structures necessary for protein synthesis

74. Which of the following statements about the nucleoli is incorrect?
a) Nucleoli assemble ribosomal subunits
b) Nucleoli synthesise rRNA
c) Nucleoli are composed of RNA, histones and enzymes
d) Nucleoli contain structures necessary for protein synthesis
e) Nucleoli release ribosomes by carrier mediated transport at the nuclear pores

d) Form part of the plasma membrane

75. What is the function of DNA?
a) Carry genetic information from the nucleus to the cytoplasm
b) Increase the rigidity of the cell
c) Store the information required for protein synthesis
d) Form part of the plasma membrane
e) Regulate the entrance of molecules into the nucleus

a) DNA is supercoiled around histones within the nucleus

76. Which of the following statements is correct?
a) DNA is supercoiled around histones within the nucleus
b) DNA and histones form chromatin in dividing cells, but visible chromosomes in non-dividing cells
c) Humans have 22 pairs of chromosomes
d) A gene is a section of DNA equal to half of a total chromosome
e) Coiling of DNA does not allow for effective packaging of DNA

d) both A and B

77. Which of the following statements is correct?
a) mRNA is identical to the coding strand of DNA, except for uracil instead of thymine
b) information on mRNA is stored as a triplet of bases called a codon
c) mRNA is identical to the template strand of DNA, except for uracil instead of thymine
d) both A and B
e) both B and C

d) a section of DNA coding for the production of a particular polypeptide

78. define a gene:
a) a section of DNA bound as to histones
b) a fragment of a chromosome
c) a piece of DNA
d) a section of DNA coding for the production of a particular polypeptide
e) a section of mRNA coding for the production of a particular polypeptide

e) disruption of H bonds between DNA strands and removal of histones bound to the promoter

79. gene activation refers to:
a) the production of mRNA from DNA
b) production of a protein from mRNA
c) stimulating a cell to synthesise a gene
d) stimulation of cell replication
e) disruption of H bonds between DNA strands and removal of histones bound to the promoter

b) Statements I and ii are true

80. Consider the following statements:
i) Transcription is performed by RNA polymerase
ii) Transcription requires gene activation
iii) Nucleotides are strung together by hydrogen bonds
iv) Complementary pairing of bases is by covalent bonds
v) Once completed, RNA polymerase detaches, DNA strand come together and mRNA leaves the cell
a) All statements are true
b) Statements I and ii are true
c) Statement v is false
d) Statements iii and iv are false
e) Statements I, ii, iv and v are true

c) 3, 5, 4, 6, 2, 1

81. Consider the following steps to translation:
1. ribosome moves along mRNA until it reaches a stop codon and is detached
2. first tRNA is released, leaving a growing chain of amino acids
3. mRNA leaves nucleus by nuclear pore and encounters a ribosome
4. second tRNA binds to next site
5. tRNA anticodon binds to mRNA start codon, facilitated by ribosome
6. peptide bond forms between amino acids at the tails of tRNA molecules
The correct order of these steps is:
a) 2, 3, 5, 1, 6, 4
b) 3, 5, 4, 2, 6, 1
c) 3, 5, 4, 6, 2, 1
d) 2, 3, 5, 6, 4, 1
e) 3, 5, 2, 6, 4, 1

b) A permanent change in the nucleotide sequence of a gene

82. The best definition of a mutation is:
a) An insertion of an extra amino acid to a protein
b) A permanent change in the nucleotide sequence of a gene
c) A substitution of one nucleotide for another
d) The production of abnormal mRNA
e) The loss of function of a body organ

c) M

83. Which of the following is not part of interphase?
a) G0
b) S
c) M
d) G1
e) G2

c) The cell performs normal cell functions (may be a permanent state)

84. What is occurring during the G0 phase of the cell cycle?
a) The cell goes through normal functioning and organelle replication
b) The cell duplicates DNA and histones
c) The cell performs normal cell functions (may be a permanent state)
d) The cell performs further growth and prepares to enter M phase (e.g. centriole replication
e) The cell undergoes mitosis

a) The cell goes through normal functioning and organelle replication

85. What is occurring during the G1 phase of the cell cycle?
a) The cell goes through normal functioning and organelle replication
b) The cell duplicates DNA and histones
c) The cell performs normal cell functions (may be a permanent state)
d) The cell performs further growth and prepares to enter M phase (e.g. centriole replication
e) The cell undergoes mitosis

b) The cell duplicates DNA and histones

86. What is occurring during the S phase of the cell cycle?
a) The cell goes through normal functioning and organelle replication
b) The cell duplicates DNA and histones
c) The cell performs normal cell functions (may be a permanent state)
d) The cell performs further growth and prepares to enter M phase (e.g. centriole replication
e) The cell undergoes mitosis

d) The cell performs further growth and prepares to enter M phase (e.g. centriole replication

87. What is occurring during the G2 phase of the cell cycle?
a) The cell goes through normal functioning and organelle replication
b) The cell duplicates DNA and histones
c) The cell performs normal cell functions (may be a permanent state)
d) The cell performs further growth and prepares to enter M phase (e.g. centriole replication
e) The cell undergoes mitosis

e) Both strands of DNA are replicated from the same end

88. Which of the following statements about DNA synthesis is incorrect?
a) The replication is semi-conservative
b) Replication is by DNA polymerase
c) Replication is in a 5' to 3' direction only
d) All information is retained in each cell division
e) Both strands of DNA are replicated from the same end

d) Metaphase

89. Which part of the mitotic cycle could be described as "chromosomes align along the centre of the cell"?
a) Anaphase
b) Telophase
c) Cytokinesis
d) Metaphase
e) Early prophase

b) Late prophase

90. Which part of the mitotic cycle could be described as "nuclear envelope disappears, centrioles separate and migrate to opposite ends of the cell, spindle apparatus appears"?
a) Early prophase
b) Late prophase
c) Anaphase
d) Metaphase
e) Telophase

a) Early prophase

91. Which part of the mitotic cycle could be described as "duplicated chromosomes join at centromere and become tightly coiled"?
a) Early prophase
b) Late prophase
c) Anaphase
d) Cytokinesis
e) Telophase

c) Cytokinesis

92. Which part of the mitotic cycle could be described as "cytoplasmic division of daughter cells, beginning in late anaphase and caused by constriction of myosin and actin"?
a) Metaphase
b) Telphase
c) Cytokinesis
d) Interphase
e) Late prophase

a) Anaphase

93. Which part of the mitotic cycle could be described as "centromeres split, chromosomes move to opposite ends of the cell by action of kinetochore and microtubules"?
a) Anaphase
b) Metaphase
c) Telophase
d) Early prophase
e) Late prophase

e) Telophase

94. Which part of the mitotic cycle could be described as "nuclear envelope reforms, nucleoli reappear, chromosomes uncoil and nuclei enlarge"?
a) Early Prophase
b) Late prophase
c) Metaphase
d) Anaphase
e) Telophase

e) There is no regulation of cell cycle once it has begun

95. Which of the following is incorrect regarding checkpoints of the cell cycle?
a) Checkpoints are regulated by the presence of maturation promoting factor
b) Checkpoints are at G1 to S transitions
c) Checkpoints are at G2 to M transition
d) Checkpoints are during metaphase
e) There is no regulation of cell cycle once it has begun

a) Chromosomal caps which prevent cell division after too many previous divisions

96. What are telomeres?
a) Chromosomal caps which prevent cell division after too many previous divisions
b) Genes which direct controlled cell death
c) Proteins responsible for the repair of DNA
d) Genes that promote cell growth
e) Genes that inhibit cell growth

e) All statements are true

97. Which statement about proto-oncogenes is true?
a) Proto-oncogenes promote cell division
b) Proto-oncogenes are deactivated unless stimulated (e.g. by a hormone)
c) Proto-oncogene may mutate to oncogenes
d) An oncogene can lead to cancer
e) All statements are true

b) Encode proteins to slow cell proliferation

98. Tumor suppressor genes:
a) Increase the rate of mitosis
b) Encode proteins to slow cell proliferation
c) Promote active cell death
d) Destroy defective cells
e) Repair DNA

d) An increased probability of mutations in many genes

99. A mutation in DNA repair genes may lead to:
a) Cardiovascular problems
b) Bone degeneration
c) A lack of DNA synthesis
d) An increased probability of mutations in many genes
e) None of the above

a) Apoptosis is programmed cell death while necrosis is passive cell death

100. How is apoptosis different to necrosis?
a) Apoptosis is programmed cell death while necrosis is passive cell death
b) Apoptosis has more inflammation induced than necrosis
c) Necrosis is a normal physiological process
d) Necrosis affects an isolated cell while apoptosis affects a group of cells
e) Apoptosis is always induced by bacteria