BIO 1109 Midterm Exam – October 6, 2004 Name: ______________________________ Student Number: _____________________ BIO 1109 – Principles of Biology Midterm examination I Worth either 30% or 40% of your final grade Monday October 6, 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 12 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: .............................................................................................. Page 1 of 12 BIO 1109 Midterm Exam – October 6, 2004 Name: ______________________________ Student Number: _____________________ 15 pts Part 1. Briefly explain what each of the following biological terms means. Where possible include an example to which the term applies. Tertiary protein structure {Folding and twisting} of a protein that creates the {3D shape} and {held together by a variety of different types of bonds/held together by functional group or R-group interactions} {1},{1},{1} Anticodon {on the tRNA molecule}{consists of the three bases} {contains the complementary sequence for the amino acid coded in mRNA}{1},{1},{1} Intron {Noncoding part}{Eukaryote mRNA/primary transcript}{Removed to make final mRNA/removed before leaving nucleus} {1},{1},{1} Cell theory {All living things are made of cells – must say living}{cells are self replicating}{cells can only come from cells} {1},{1},{1} Amino acid {Basic unit/monomer}{of protein/peptide}{connected to each other by peptide bonds}{Have R/functional groups with different properties}{1},{1},{1} in any order to a maximum of 3pts Page 2 of 12 BIO 1109 Midterm Exam – October 6, 2004 Name: ______________________________ Student Number: _____________________ 30 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 What is a hypothesis? X A. a tentative statement, based on data, that can be used to guide further observations and ________ experiments ________ B. a report of the findings of scientific experiments ________ C. a general statement made to infer a specific conclusion, often in an “if . . . then” format ________ D. using isolated facts to reach a general idea that may explain a phenomenon ________ E. If data from experiments do not support a hypothesis, the hypothesis must be rejected or revised. 2.2. Which is NOT a characteristic of mitochondria? ________ A. A mitochondrion has two membranes. ________ B. Mitochondria are the site of cellular energy production. X C. Mitochondria are found in prokaryotic and eukaryotic cells. ________ ________ D. Mitochondria contain DNA and ribosomes. 2.3. Which occurs in anaphase? ________ A. Centrioles move to opposite poles. ________ B. Chromosomes line up along the equator of the dividing cell. X C. Chromosomes move to opposite poles. ________ ________ D. The nuclear envelope disappears. ________ E. The nuclear envelope is constructed. 2.4 Unicellular prokaryotes ________ A. lack a membrane bounded nucleus ________ B. are found in the domains Bacteria and Archaea ________ C. are found in almost all habitats ________ X D. all of the previous Page 3 of 12 BIO 1109 Midterm Exam – October 6, 2004 Name: ______________________________ Student Number: _____________________ 2.5. Which of the following statements is NOT true about electron configurations? ________ A. If an atom has only one shell, it is complete with two electrons. ________ B. If an atom has two or more shells, the octet rule applies. ________ C. If an atom has two or more shells, the outer shell is complete with eight electrons. ________ X D. Atoms with more than eight electrons in the outer shell react by gaining electrons. ________ E. Atoms with eight electrons in the outer shell are not reactive at all. 2.6 Which statement is NOT true about bacteria? ________ X A. Their cell wall is made of a slime layer that is the same as in plant cell walls. ________ B. Some are photosynthetic. ________ C. Some are chemosynthetic. ________ D. They are all prokaryotes. ________ E. They have a cell wall that contains peptidoglycan. 2.7 Which statement is NOT true about ionic bonds? ________ A. One atom acts as an electron donor and another acts as an electron acceptor. ________ B. Electrons are completely lost or gained in ion formation. ________ X C. An ion has the same number of electrons as a nonionic atom of the same element. ________ D. An ionic reaction occurs between positive ions and negative ions. ________ E. A salt such as NaCl is formed by an ionic reaction. 2.8 Which of these statements is NOT true about DNA? ________ A. It is the genetic material of the cell. ________ B. It forms a double helix. ________ C. Adenine pairs with thymine and guanine pairs with cytosine. X D. It contains the sugar ribose. ________ ________ E. The sugar and phosphate groups form the backbone of the molecule. 2.9 A lipid is a polymer made up of which kind of monomers? ________ A. glucose or modified glucose molecules ________ B.amino acids ________ C. nucleotides ________ D. alternating sugar and phosphate groups X E. fatty acids and glycerol ________ Page 4 of 12 BIO 1109 Midterm Exam – October 6, 2004 Name: ______________________________ Student Number: _____________________ 2.10 Which carbohydrate is used in the liver for energy storage? ________ A. starch ________ B. chitin ________ C. cellulose ________ X D. glycogen ________ E. glycerol 2.11. A peptide bond is found in which type of biological molecule? ________ A. carbohydrate ________ B. lipid ________ C. nucleic acid ________ X D. protein 2.12 Fish sperm consists mostly of the male fish’s DNA. If we tested a sample chemically, we should find relatively high amounts of ________ X A. nitrogenous bases, sugar, and phosphate groups. ________ B. phospholipids and steroids. ________ C. amino acids and unsaturated fats. ________ D. triglycerides and ATP. ________ E. globular proteins and stored fats. 2.13. Biopolymers are ________ A. large organic molecules linking together repeating subunits of the same type called monomers. ________ B. found in proteins, carbohydrates, and nucleic acids. ________ C. due to a dehydration reaction. X D. all of the previous. ________ 2.14. What is the importance of crossing-over? ________ A. It provides extra genetic material for the daughter cells. ________ X B. It increases the likelihood that daughter cells contain different genetic material. ________ C. It produces the proteins that are associated with DNA in chromosomes. ________ D. It increases chromosome condensation. ________ E. It separates the homologous chromosomes. Page 5 of 12 BIO 1109 Midterm Exam – October 6, 2004 Name: ______________________________ Student Number: _____________________ 2.15. Which of these is NOT part of the endomembrane system of the cell? ________ X A. mitochondria ________ B. endoplasmic reticulum ________ C. lysosomes ________ D. Golgi complex 2.16 What is the process by which the sun’s energy is trapped as the source of energy used by virtually all living organisms? ________ A. evolution ________ B. metabolism ________ C. adaptation ________ D. homeostasis ________ X E. photosynthesis 2.17. Which phrase does NOT describe one of the functions of proteins of the plasma membrane? ________ A. forming a channel through the membrane X ________ B. initiating the replication of the genetic material ________ C. binding to a substance to carry it through the membrane ________ D. acting as a receptor for substances external to the cell 2.18.Stages of the cell cycle include ________ A. interphase. ________ B. mitosis. ________ C. cytokinesis. X D. all of the previous. ________ 2.19. Which term is based on the Greek root word for “water” and “fear”? ________ A. hydrostatic ________ B. homeostatic ________ C. hydrophobic X ________ D. hydrophilic ________ E. hyperphobic Page 6 of 12 BIO 1109 Midterm Exam – October 6, 2004 Name: ______________________________ Student Number: _____________________ 2.20. Which of the following is NOT associated with animal cells? ________ A. an extracellular matrix ________ X B. plasmodesmata ________ C. gap junctions ________ D. adhesion junctions (desmosomes) ________ E. tight junctions 2.21 If an animal needed to store energy for long-term use, but not be encumbered with the weight of extra tissue, which is the best molecule for storage? ________ A. fructose and glucose in the form of honey ________ X B. high-calorie fat molecules ________ C. complex cellulose molecules ________ D. starch ________ E. glycogen with extensive side branches of glucose 2.22.If phagocytosis can be compared to cellular eating, the pinocytosis can be compared to ________ A. cellular elimination. X B. cellular drinking. ________ ________ C. cellular dehydration. ________ D.none of the previous. 2.23.The amount of adenine is always equal to the amount of_______ in DNA. ________ A. cytosine ________ B. uracil ________ C. guanine X D. thymine ________ ________ E.ATP 2.24.In the model of DNA, the “steps” of the ladder are composed of ________ A. sugars. X B. a purine and a pyrimidine. ________ ________ C. two purines. ________ D. two pyrimidines. ________ E .a sugar and a phosphate molecule. Page 7 of 12 BIO 1109 Midterm Exam – October 6, 2004 Name: ______________________________ Student Number: _____________________ 2.25.On a hypothetical planet, life evolves based on a DNA-like molecule with six rather than four nucleotides. Which table reflects the number of bases for each number of codons and the corresponding number of combinations of different amino acids that could be specified? ________ A.1—4, 2—10, 3—16, 4—22 ________ B.1—6, 2—10, 3—16, 4—22 ________ C.1—6, 2—18, 3—108, 4—648 X ________ D.1—6, 2—36, 3—216, 4—1296 2.26 Which of the classes of RNA molecules carries the amino acids that are added to the growing polypeptide chain? ________ A. ribosomal RNA ________ X B. transfer RNA ________ C. messenger RNA ________ D. primary mRNA transcript 2.27.Which is the process by which a protein is constructed? X A.translation ________ ________ B.transcription ________ C.transposition ________ D. transformation 2.28 An atom’s atomic number is best described as the number of ________ X A. protons it contains. ________ B. neutrons it contains. ________ C. electrons in the outermost shell. ________ D. protons and neutrons it contains. ________ E. protons and electrons it contains. 2.29 As a solid, water floats. This means that ________ A. solid water is less dense than liquid water ________ B. organisms in ponds, lakes, and reservoirs can survive under the ice cover ________ C. this is due to hydrogen bonding changes X D. all of the previous ________ Page 8 of 12 BIO 1109 Midterm Exam – October 6, 2004 Name: ______________________________ Student Number: _____________________ 2.30. During which stage of meiosis does homologue separation occur? ________ A. prophase I ________ X B. anaphase I ________ C. telophase I ________ D. prophase II ________ E. anaphase II 10 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 ________ T A theory in science is different from the usage of the term in everyday language. 3.2 ________ T Molecules form when energy relationships occur between atoms, called chemical bonds. T Water moderates the temperatures on earth because it can absorb and release large 3.3 ________ amounts of heat. F ATP is a protein that supplies energy to the cell. 3.4 ________ 3.5 ________ F Starch is a protein that serves in energy storage in plant cells T Cells are surrounded by a plasma membrane. 3.6 ________ T The cytosol is the fluid that bathes the structures that are located in the cytoplasm. 3.7 ________ T During replication of DNA, DNA polymerase has to synthesize the daughter strand 3.8 ________ in the 5 prime to 3 prime direction because DNA polymerase can only join a 5 prime nucleotide to the free 3 prime end of another nucleotide. T Proofreading of the nucleotides keeps the error rate to one mistake per one billion 3.9 ________ base pairs during DNA replication. T A stop codon terminates polypeptide production and release from the ribosome. 3.10 _______ 10 pts Fill in the Blank: Complete the following sentences using the appropriate terms. Place the term in the space in the sentence of at the end 4.1 Transfer RNA transfers _Amino acids____ to the ribosomes. 4.2 Ribosomes have __three___________ binding site(s) for tRNA molecules. 4.3 The organized lattice of protein filaments inside the eukaryotic cell is known as the __cytoskeleton___________. 4.4 The two strands of DNA are held together by these bonds between the purine and pyrimidine bases. __hydrogen____________ 4.5 These water filled membranous sacs are only found in plants. __Vacuole___________ Page 9 of 12 BIO 1109 Midterm Exam – October 6, 2004 Name: ______________________________ Student Number: _____________________ 4.6 A eukaryote cell's genetic material is located in this structure. __Nucleus___________ 4.7 The stage of mitosis where the two daughter cells start to form. _Telophase_______________ 4.8 During the S phase of the cell cycle this is duplicated. __DNA/Genetic materials____________ 4.9 The C in CDKs that are involved in controlling the cell cycle. ____cyclins__________ 4.10 Ribosomal RNA comes from this part of the nucleus. ___Nucleolus_________________ 15 pts Part 5: Answer 3 of the following 5 questions in the space provided, each is worth 5 points 5.1 How does active transport differ from passive transport? Give an example of each. OR How does a hypertonic solution and hypotonic solution affect an animal cell and why? {Active transport burns ATP(requires energy)/passive doesn’t require energy} {Active transport moves against the concentration gradient} {Passive transport moves with the concentration gradient} {Active example – sodium potassium pump} {Passive transport – water diffusion/osmosis} Point each total 5 {Hypertonic – higher salt than the cell/Hypotonic – lower salt concentration than the cell}, {Hypertonic water comes out of cell and it shrinks}. {Hypotonic water moves into the cell and it bursts} {1},{2},{2} Page 10 of 12 BIO 1109 Midterm Exam – October 6, 2004 Name: ______________________________ Student Number: _____________________ 5.2 What happens to the viral DNA in the lytic and lysogeneic part of a viral life cycle? OR Why are viruses not considered living? In Lytic {viral DNA is replicated}and{codes for viral proteins}that are then {packaged with viral DNA to make new virus}. In lysogenic {viral DNA incorporates/combines with bacterial}{becomes a prophage/becomes inactive} {1} point each Not living because {no cell membrane} {no protein synthesis/ribosomes} {no energy system/mitochondria} {made of only DNA/RNA wrapped in protein} 2 points for the first no matter what order, 1 point for remainder to a maximum of 5. 5.3 Compare Meiosis 1 and Mitosis OR Compare Meiosis II and Mitosis See table 10.1, 10.2 page 174. Answer must include at least three of the rows in these tables and the first and second correct and complete rows score 2 points each third row 1 point. For a total of five points Page 11 of 12 BIO 1109 Midterm Exam – October 6, 2004 Name: ______________________________ Student Number: _____________________ 5.4 A number of enzymes are involved in DNA replication, what are the enzymes and what does each do? OR Describe the events during the elongation step of translation. {RNA polymerase – creates a double strand/primer} {Helicase, unwinds the helix) (DNA polymerase – {duplicates the DNA}, {proofreads the DNA}, {adds at 3’end}) {Ligase, seals up the pieces} 1,1,3,1 {tRNA in P site has attached growing peptide}, {tRNA with amino acid enters A site}, {peptide bond made freeing amino acid from tRNA in P}, {tRNA from P shifts t X/E site and leaves}, {tRNA in A with growing peptide chain moves to P freeing A} 5.5 Explain the biological significance of the acronym CHNOPS. OR How are covalent bonds formed? CHNOPS – {the most common elements(must say elements, no compounds, molecules)},{Found in living things} {Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorous, and Sulfer} {1},{1}.{0,5 for each element} {By sharing paired electrons}, {Obeys octet rule} {octet says 8 in outer orbital}, {except inner with 2} {diagram or representation of a covalent bond} 2,1,1,1 to a maximu of 5 – doesn’t matter which scores the 2 points. Page 12 of 12