97' SBIOA Exam

Note:  I have used the terms NADH and NADH₂ and NADH/H⁺ interchangeably (i.e., they are all meant to be equal in meaning. So don’t look for tricks there.  Also, if I haven’t subscripted or superscripted stuff, don’t get hung up on that either.

Page 1       Page 2         Page 3       Page 4       Page 5 

31.                  Identify the mRNA sequence that will result from the transcription of the sequence of DNA which reads, “GTAGTAGGT”?

a)                  GTAGTAGGT

b)                 CAUCAUCCA

c)                  UCGUCGUUC

d)                 AUGAUGAAU

e)                  CATCATCCA

32.                  Which of the following statements about food chains and energy flow through ecosystems is FALSE?

a)                  A single organism can feed at several trophic levels.

b)                 Herbivores feed at all trophic levels except the producer level.

c)                  The lower the trophic level at which an organism feeds, the more energy available.

d)                 Food webs include two or more food chains.

e)                  All organisms that are not producers are consumers.

33.                  Consider the following:

maleate ± oxaloacetate + 2e^- + 2H⁺

         NAD⁺ + 2e^- + 2H⁺ ± NADH + H⁺

           The overall reaction is: NAD⁺ + maleate ±  NADH + H⁺ + oxaloacetate

           Which statement is FALSE?

a)                  Maleate is oxidized to oxaloacetate.

b)                 NAD⁺ participates in a redox reaction.

c)                  Maleate is reduced.

d)                 NAD⁺ is reduced.

e)                  NADH can be used as a reducing agent for other synthetic reactions in the cell.

34.                  The DNA of an organism has cytosine as 20 percent of its bases. What percentage of DNA bases would be thymine?

a)                  10

b)                 20

c)                  40

d)                 30

e)                  60

35.                  An excess supply of (which of the following nutrients) is the most common cause of eutrophication or algal bloom  in freshwater lakes in Canada?

a)                  Phosphorus

b)                 Calcium

c)                  Sulfur

d)                 Potassium

e)                  Nitrogen

36.                  Which statement is FALSE?

a)                  Glucose-6-phosphate is an intermediate in glycolysis.

b)                 Pyruvate from glycolysis enters the mitochondrion and is converted to acetyl coenzyme A.

c)                  Some energy from ATP is required for glucose to enter the glycolysis process.

d)                 For each glucose molecule broken down during aerobic respiration, the citric acid cycle produces more ATP molecules than does the electron transport chain.

e)                  The energy to make ATP comes from a proton gradient across the inner mitochondrial membrane, which is made by passing electrons through the electron transport chain.

37.                  On a per mole basis, fats are a better source of energy than carbohydrates because:

a)                  fats are most like proteins.

b)                 the oxidation of fats produces larger quantities of ATP.

c)                  fats contain many highly oxidized carbon atoms.

d)                 fats are heavier than carbohydrates.

e)                  fats are broken down by glycolysis.

38.                  Which statement about the Calvin cycle is FALSE?

a)                  It uses NADH as a reductive supply (or “power source”).

b)                 The initial carboxylation reaction is catalysed by the enzyme RUBP carboxylase (Rubisco).

c)                  The reduction of PGAL to a sugar phosphate requires ATP, NADPH+, and H+.

d)                 It is a process which involves enzymes that are light activated.

e)                  The Calvin cycle is found in heterotrophic cells but not in autotrophic cells.

39.                  Which statement best defines evolution?

a)                  The close resemblance between parents and their offspring

b)                 Difference between individuals in survival

c)                  Individuals in two populations look different

d)                 Change in the phenotype of an individual through time

e)                  Change in genetic composition of a population

These next 8 questions are worth 2 marks each.

40.              Which of the following statements is FALSE?

a)                  In an exergonic reaction, energy released as reactants with a relatively high energy content form products with a lower energy content.

b)                 Energy is not required for an endergonic reaction as reactants with a relatively low energy content are promoted to products with a higher energy content.

c)                  The hydrolysis of ATP, yielding approximately -7.3 kcal/mole, ADP, and Pi, is coupled with the formation of glucose phosphate that requires +4 kcal/mole.

d)                 The principle of conservation of energy is called the First Law of Thermodynamics.

  <-Page 3   ---  Page 4 ---   Page 5->