bio 1109 – principles of biology midterm examination 2...

BIO 1109 Midterm Exam –November 10, 2004 Name: _____________________________ Student Number:_____________________________

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BIO 1109 – Principles of Biology

Midterm examination 2 Worth either 30% or 40% of your final grade

Wednesday, November 10, 2004

a) Place your name and student number in the space provided below. Be sure that your name is

on the top of each page because the exam may be separated to facilitate marking

b) Check to be sure that your exam is complete with a total of 13 pages including this one

c) Answer all questions in the space provided on the exam. Do not transfer answers to the back of the page

d) This is not an open book examination. Name: ........................................................................................................... Student No: ...................................................................................................


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15 pts Part 1. Briefly explain what each of the following biological terms means. Where possible include an example to which the term applies. Transition reaction (in metabolism) {links glycolysis and TCA/Citric acid cycle}{Pyruvate(3C) loses a carbon}{produces

acetylCoA} Point each Nucleosome {piece of DNA}{wound around a core of histone proteins){string of beads}{may be wound on

them selves to form coiled nucelosomes}{2 points for the first two that must be present} a single pint for additional to a maximum of three

Endosymbiont theory {origins of eukaryote cells}{engulphs/phygocytosis of a prokaryote}{Cell with a

nucleus/endomembrane system surrounding nucleus}{includes mitochondria in all eukaryotes/chloroplasts in plants} {11, first two must be present} and other 1 for a maximum of three points

Central dogma of Biology {DNA produces DNA}{RNA comes from DNA, occasionally reversed with retrovirus } and

{Proteins from RNA} This can be presented as a diagram, 1 point each, in the second retrovirus statement is not required but may be provided by some students.

Polyploid {chromosome number} {greater than the usual diploid number} {found in plants/lethal in animals} Point each either, or both parts of the third may be used as the example.


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25 pts Part 2 Answer each of the following multiple choice questions by placing and X in the space to the left of the correct choice. There is only one correct answer for each question and questions have either 4, 5 or 6 answers to choose from. Be sure your X doesn’t cross over two answers – if it does the question will be scored as 0.

2.1 Which best describes the second law of thermodynamics?

____________A. Energy is not created nor destroyed, but it can change into matter.

____________B. Energy is not created nor destroyed, but it can change from one energy form

to another.

____________C. Energy can be created from matter or used to produce matter.

____________D. Some useful energy is lost as heat whenever an energy transfer occurs.

____________E. Energy transfers are always 100% efficient in changing energy from one

useful form to another.

2.2 Which of these processes occurs in the cytosol?

____________A. the Krebs cycle

____________B. glycolysis

____________C. the electron transport system

____________D. the transition reaction

2.3 What establishes the electrochemical gradient across a membrane to provide energy for ATP

production?

____________A. The chloroplast’s electron transport system provides the ions.

____________B. Hydrogen ions naturally collect on the outside of the organelle membrane.

____________C. Hydrogen ions are pumped across the membrane by carrier proteins.

____________D. All of the above establish the electrochemical gradient.

2.4 Which pairing of occurrence and date is NOT correct?

____________A. origin of multicellular organisms—550 million years ago

____________B. origin of life—4.8 billion years ago

____________C. origin of eukaryotic cells—1.5 billion years ago

____________D. All the above are incorrect.

2.5 What are the products of photosynthesis?

____________A. water and carbon dioxide

____________B. water and oxygen

____________C. oxygen and carbohydrate

____________D. carbohydrate and water

X

X

X

X

X


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2.6 The first reaction in the Krebs cycle is binding

____________A. carbon dioxide to a four-carbon (C4) molecule.

____________B. carbon dioxide to a five-carbon (C5) molecule.

____________C. acetyl-CoA to a C4 molecule.

____________D. acetyl-CoA to a C5 molecule.

2.7 Bacterial cells pick up free pieces of DNA from the medium–pieces that were secreted by live

bacteria or released from dead bacteria–in a process called

____________A. transformation.

____________B. transduction.

____________C. conjugation.

____________D. infection.

____________E. replication.

2.8 The first event in the Calvin cycle is the attachment of carbon dioxide to the five-carbon

RuBP molecule, which

____________A. forms a six-carbon molecule that immediately breaks down into two

three-carbon PGA molecules.

____________B. is a reaction assisted by large quantities of RuBP carboxylase enzyme.

____________C. decreases cell carbon dioxide levels, which increases the diffusion gradient.

____________D. immediately becomes a six-carbon sugar that is the base for starch, sucrose,

cellulose, etc.

____________E. Answers A, B, and C are correct.

2.9 Prokaryotae are now divided into the

____________A. archaea and cyanobacteria.

____________B. bacteria and cyanobacteria.

____________C. photosynthetic bacteria and chemosynthetic bacteria.

____________D. archaea and bacteria.

____________E. autotrophs and heterotrophs.

2.10 Which statement is NOT true about genetic control in prokaryotes?

____________A. RNA polymerase must bind to a promoter on the DNA to begin RNA

synthesis.

____________B. Most gene expression is regulated at the level of translation.

____________C. An active repressor protein keeps RNA polymerase from binding to DNA.

____________D. Structural genes produce enzymes that act in a metabolic pathway.

X

X

X

X


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2.11 The first level of primary control in eukaryotic gene activity is _______ control.

____________A. feedback

____________B. translational

____________C .transcriptional

____________D. posttranscriptional

____________E. posttranslational

2.12 The Calvin cycle requires all of the following except _____________ to occur.

____________A. ATP,NADPH

____________B. carbon dioxide

____________C. light

____________D. ribulose bis-phosphate

2.13 Skin color in humans, caused by several genes at several loci, is an example of

____________A. multiple alleles at one locus.

____________B. incomplete dominance.

____________C. epistasis.

____________D. pleiotropy.

____________E. polygenic inheritance.

2.14 If the parents are AO and BO genotypes for the ABO blood group, their children could

include which ofthe following genotypes?

____________A. AO and BO only

____________B. AO, BO, and AB only

____________C. AA, BB, and AB only

____________D. AO, BO, and OO only

____________E. AO, BO, AB, and OO only

2.15 A line of evidence NOT considered by Darwin in his development of the theory of natural

selection is

____________A. comparative anatomy.

____________B. biogeography.

____________C. the fossil record.

____________D. comparative embryology.

____________E.c omparative biochemistry.

X

X

X

X

X


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2.16 All the members of a single species that occupy a particular area at the same time are known

as a

____________A. subspecies.

____________B. gene pool.

____________C. population.

____________D. group.

____________E. sub-population.

2.17 What is the term used to describe the accumulation of small changes in the gene pool of a

species over time?

____________A. genetic drift

____________B. founder effect

____________C. microevolution

____________D. directional selection

2.18 ATP

____________A. supplies energy needed to synthesize macromolecules within the cell.

____________B. supplies energy required to pump substances across the plasma membranes.

____________C. is the energy source for muscles to contract.

____________D. all of the previous.

2.19 If the Hardy-Weinberg equilibrium is met, what is the net effect?

____________A. evolution leading to a population better adapted to an unchanging

environment

____________B. evolution leading to a population better adapted to a changing environment

____________C. very slow and continuous evolution with no increased adaptation

____________D. no evolution because the alleles in the population remain the same

2.20 Which level of primary control in eukaryotic gene activity involves processing early RNA

transcripts to mRNA and control of the rate at which mRNA leaves the nucleus?

____________A. feedback control

____________B. translational control

____________C. transcriptional control

____________D. posttranscriptional control

____________E. posttranslational control

X

X

X

X

X


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2.21 The Greek root words for “arrange” and “law” underlie the biological term

____________A. binomial.

____________B. taxonomy.

____________C. systematics.

____________D. nomenclature.

____________E. systema naturae.

2.22 Of these categories which is highest in classification hierarchy, that is, it includes the rest of

the categories given?

____________A. order

____________B. genus

____________C. class

____________D. family

____________E. phylum

2.23 Single celled eukaryotic cells belong to which of the following kingdoms?

____________A. Monera

____________B. Protista

____________C. Fungi

____________D. Animalia

____________E. Plantae

2.24 The appearance of photosynthetic cyanobacteria and aerobic bacteria

____________A. led to the development of an oxidizing atmosphere on Earth.

____________B. led to the formation of the ozone shield.

____________C. The amount of UV light reaching the Earth was reduced and chemical

evolution slowed.

____________D. all of the previous.

2.25 What evidence would be studied by a biogeographer?

____________A. continental drift or the movement of tectonic plates over time

____________B. amount of genetic similarity among current populations

____________C. ocean currents and wind patterns

____________D. ranges of animals and ability to migrate

____________E. All of the above are correct.

X

X

X

X

X


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20 pts Part 3: Indicate whether the following statements are true of false by placing a T (true) or F (false) in the space provided at the beginning of the statement.

3.1 _____An example of an inducible operon is the lac operon.

3.2 _____As energy is converted into heat and work in a cell, the energy will either leave the cell

or be stored in various chemical bonds.

3.3 _____ Fossil fuels are full of energy stored from photosynthesis millions of years ago.

3.4 _____Light-dependent reactions occur after light-independent reactions in the process of

photosynthesis.

3.5 _____The most efficient pathway for ATP production in animal cells is by glycolysis.

3.6 _____The Hardy-Weinberg equilibrium is usually met in most populations in changing

environments.

3.7 _____ATP is produced and used continuously in all active cells.

3.8 _____Glycolysis is linked to the Krebs cycle when oxygen is not available.

3.9 _____Probably the most important means of gaining new genetic material for prokaryotic

evolution is sexual recombination.

3.10 ____Mendel developed a blended theory of inheritance.

3.11 ____If an individual is heterozygous for a particular trait, the gametes that individual

produces will contain 3/4 dominant and 1/4 recessive alleles.

3.12 ____Chemiosmotic ATP synthesis occurs in the cytosol of the cell.

3.13 ____Linnaeus, who developed the binomial system of naming species, was a strong

supporter of the theory of evolution.

3.14 ____One of the unifying theories of biology is the theory of evolution.

3.15 ____An allele becomes the most common allele in a population by becoming the dominant

allele.

3.16 ____Mendel's work was widely accepted and praised when he reported his results.

3.17 ____The Great Salt Lake would be an excellent location to find methanogens.

3.18 ____The cell wall of the bacteria contains a molecule found nowhere else called

peptidoglycan.

3.19 ____Active cells must continually produce ATP.

3.20 ____Evolution can be described as the change of species over time.

T T

T F

F F

T F F

F F

F F

T F

F F T

T T


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30 pts Part 4: Use one or two words to answer the question, or complete the sentence. Place your answer in the space provided or at the end of the question if the line is missing. 4.1 Solar energy is stored in ATP and this compound during photosynthesis ___NADPH_______

4.2 This metabolic process produces both NADH and FADH2. __Krebs/citric acid___________

4.3 The traits Mendel studies in garden peas showed this kind of dominace. ___Complete______

4.4 These vents in the deepest parts of the oceans may also be the original site of the formation of

the first organic chemicals. _____Hydrothermal____________

4.5 Shape of the bacterial genome. ___Circular_______________

4.6 These breakdown carbohydrates during digestion. _Charbohydrases_______________

4.7 Life's process are regulated and kept in balance, a biological process referred to

as this. ___homeostasis___________

4.8 Simple bacterial cell duplication.___Binary fission_______________

4.9 The stacked disks in a chloroplasts.___Thylakoids______________

4.10 This organelle captures the sun's energy. __Chloroplast______________

4.11 If the sugars and amino acids that result from digestion are formed inside the cell it's this type

of digestion. ___Intracellular_______________

4.12 These bacteria produced the natural gas that we currently burn as fuel. ____Methanogens___

4.13 Taxon above a family but below a class. __Order______________

4.14 Unlike organisms in the other two domains, bacteria don't have these interrupting the gene

sequence. ___Introns_________________

4.15 Preventing the production of the primary RNA transcript is an example of this type of

control. ____Transcriptional_________________

4.16 This part of the range of variation is selected for in disruptive selection. __Middle_________

4.17 Electron transport system is found on this part of mitochondria. _Cristae/Inner

membrane___

4.18 Photosynthesis shuts down in the presence of oxygen, especially when the stomata are closed.

When that happens this occurs. __Photorespiration________________

4.19 The energy of motion. ___Kinetic_________________

4.20 In English grammar the species epithet or part of the name would be this. __Adjective______

4.21 Every animal in a taxon shares this type of ancestor. ___Common________________

4.22 Number of carbons in the molecule at the start of glycolysis. ____Six_____________

4.23 The final step in digestion is to break down the biopolymers of protein, carbohydrate, and

lipids into these so that they can be used by the cell. __Monomers______________


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4.24 Will CAP be bound or unbound to the lac operon when lactose is low and glucose is

elevated? ____Unbound________________

4.25 Swamp gas, natural gas, and bovine flatulence all have this archaean produced gas in

common. __Methane_________________

4.26 Bacterial locomotary structure. ___flagellum_______________

4.27 Conditions of low pH. ___acidic________________

4.28 Transcription occurs only in this type of chromatin. __Euchromatin/Unwound___________

4.29 The evolutionary history of a group of organisms is expressed as its ___Phylogeny________

4.30 Jumping genes. __Transposons____________

15 pts Part 5: Answer 3 of the following 6 questions in the space provided, each is worth 5 points. 5.1 Various conditions can alter the activity of an enzyme, briefly what are these and what

results? OR

Why are plants green and how is this related to photosynthesis {substrate concentration – as it rises so does enzyme activity} {enzyme concentration – the more enzyme the more activity} {Temperature – rises to a point when activity crashes because of protein denaturation/damage

from heat} {Inhibitors – of either the active site or allosteric/other site on the surface, can shut the enzyme

down} {pH – enzymes have optimal/favoured pH for activity of of this there is less activity} {co factors – some enzymes need minerals or other inorganic cofactors} {2},{2},{1} Only need to give three with an explanation point for the condition and pint for the

result. Score third as a single point for a maximum of five OR

{Reflect back the green light/absord the rest of the spectrum} {Chloryphyll}{a and

b}{Carotenoids} are the absorbing pigments {Blue/red/violet parts of the spectrum used} point each to a total of five


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5.2 Describe the planet earth during the Archeon eon be sure to include what identifies the start and the end of the eon.

OR What are the RNA-first and Protein-first theories trying to explain? {Starts with first living things – archean bacteria/prokaryotes}{ends with the oxygen atmosphere still only bacteria}{Age of bacteria/prokaryotes}{no oxygen in air/reducing environment}{archea or extreme bacteria} {genome swapping between bacteria} {from 3.8 - 2.5 billion years ago} First three must be there for three points and of the others to a maximum of 5 points

OR {How were the first biopolymers formed*} RNA first says that {RNA strands were first biopolymers* and proteins came latter} {had catalytic abilities} {supported by recent findings of rNA catalysis} {matches direction of central dogma} Protein first says that {proteins were first biopolymers and RNAor DNA can after*} {supported by proteins being the usual catalysts} 3* points must be there for a point each, a supporting piece of evidence one for each only to give the full five points. 5.3 What is an operon what are its parts and what does each do?

OR What does the regulator gene of an operon produce and how does its product regulate gene

activity? {Promotor} – {Binds RNA polymerase} {Operator} – {Site where the repressor can bind} {Structural genes – the genes coding to be translated} Note: The regulator gene is outside the operon

OR {Located outside the operon}{produces a protein} {that binds to Operator} {If bound prevents translation} {acts as an on/off switch} {May be inducible / repressable} First four must be there and a point each, either of the last two to give a maximum of five


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5.4 Explain the following: a monohybrid cross and a testcross. OR

Mendel’s findings resulted in two laws of genetics, what are they and what does each explain? Monohydrid cross {homozygous recessive tt x homozygous dominant TT} results {heterozygote

Tt} young/F1 TestCross { any individual} x {homozygous recessive tt} 3 points for monohybrid {2 for use of terms and letters/ one for of either} {1} and point each as

indicated for testcross {Law of segregation}: {two alleles/foactors per trait} {allelels separate during gamete formation/

gamete ges only one of each}{recombine and return to two on fertilization {Independent assortment} {alleles/trait sort mix in new organism independent of each other}{can

mix and match in any number of ways} 5.5 Trace carbons through one of the following: Glycolysis, Kreb’s cycle, or the Calvin cycle. Kreb’s Cycle:{2 carbon acetyl CoA}{combines with 4C oxaloacetate}{to produce 6C citric acid} {2C removed as carbon dioxide}{rebuild the oxaloacetate from the remaining 4C after the carbon dioxides are removed} 1:1:1:1:1 Glycolysis {6C glucose start}{activated into 6C fructose diphosphate}{split in two to make 2 PGAL phosphoglyceraldehyde glyceraldehydes 3 phosphate}{transformed into 3C pyruvate} 1:1;2;1;1 Calvin cycle: {5C compound}{combines 1C in Carbon dioxide} {unstable and breaks into 3C phosphoglycerate}

{6x3C with one to building}{remaining 5X3C changes to 3X 5C} 1:1:1:1:1


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5.6 Changes in chromosomal structure can be a source of variation, what kinds of changes can occur? Explain each.

OR What is the difference between homologous and analogous structures, which are best for determining how groups or organisms are related to each other and why? Inversion: a,b,c,d,e,f,g, becomes a,b,d,c,e,f,g Translocation: two chromosomes swap pieces Deletion a,b,c,d,e,f,g becomes b,c,d,e,f,g, Duplication: a,b,c,d,e,f,g, becomes a,b,c,d,e,f,d,e,f,g {2 for the first properly described and a point each for the rest to a maximum of five Homologous: {Different function but have the same origin/embryology/developmental} {ex: wings of birds, bats etc} Anologous: {Same function but have different origin/embryology/developmental} ex: wing of an insect and a vertebrate wing} {Homologies are best for figuring out who is related} point eah to a maximum of five

bio 1109 – principles of biology midterm examination 2...

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