"gooUNIVERSITY OF NEW ENGLANDNAME:___________________________________STUDENT NUMBER:_______________________ UNIT NAME:BIOL110PAPER TITLE:Biology IPAPER NUMBER:First and Only TIME ALLOWED:Two (2) hours and fifteen minutes NUMBER OF PAGES IN PAPER: EIGHT (8) NUMBER OF QUESTIONS ON PAPER: THIRTY (30)NUMBER OF QUESTIONS TO BE ANSWERED: TWENTY NINE (29)GENERALPURPOSE STATIONERY 6 LEAF A4 ROUGH WORK BOOKS BOOK3 0 0 ANSWER SHEET PERCANDIDATE: GRAPHSEE OTHER12 LEAF A4 PAPER„AIDSBOOKS0 0 0 REQUIRED?SHEETS BELOW OTHER AIDS REQUIRED: NILPOCKET CALCULATORS PERMITTED:(SILENT TYPE) YES TEXTBOOKS OR NOTES PERMITTED: NIL INSTRUCTIONS FOR CANDIDATES:• Candidates MAY NOT start writing until instructed to do so by the supervisor • Please pay attention to the announcements and read all instructions carefullybefore commencing the paper • Candidates MUST write their name and student number on the top of this page • Answer SECTIONS A to C in separate answer booklets • Section A:- answer ALL questions • Section B:- answer ALL questions • Section C:- answer THREE (3) out of FOUR (4) questions • Section D:- answer ALL questions ON THIS EXAMINATION PAPER • This examination question paper MUST BE HANDED IN with worked scripts. Failure to do so may result in the cancellation of all marks for this examination REMEMBER TO WRITE YOUR NAME AND STUDENT NUMBER AT THE TOP OF THIS PAGETHE UNIVERSITY CONSIDERS IMPROPER CONDUCT IN EXAMINATIONS TO BE ASERIOUS OFFENCE. PENALTIES FOR CHEATING ARE EXCLUSION FROM THE UNIVERSITY FOR ONE YEAR AND/OR CANCELLATION OF ANY CREDIT RECEIVED INTHE EXAMINATION FOR THAT UNIT. BIOL110, Semester 12010SECTION AUse a separate answer book for this sectionAnswer ALL questions in this section (Q. 1-3)Suggested time for SECTION A: 30 minutesQuestion 1 (12 minutes, 12 marks)Answer ALL parts of this questiona. Name a major transport system in mammals. Ans: circulatory systemb. Briefly describe why transport systems are required especially in large animals. Ans: larger animals require transport system to supply food, oxygen and other materials. The cellshave no contact with the external environment like the unicellular animals. Hence bigger organismsneed more specialized transport system for exchange of material between the external and internalenvironment.c. List what the major functions of transport systems are. Ans: the major functions are? To provide nutrients like oxygen, sugar and proteins? To collect waste substance from cell? To maintain homeostasis and pH balance? To maintain osmotic pressureQuestion 12 (8 minutes, 8 marks)List the three main types of skeletons found in animals and briefly explain their major advantages ordisadvantages (you may use a table for your answer).Ans: the three main types of skeleton are 1. Hydrostatic skeleton2. Endoskeleton3. Exoskeleton a. Hydrostatic skeletonAdvantages of hydrostatic skeleton? East access for gliding? Flexible shapeDisadvantages of hydrostatic skeleton? Gets easily killed? No support? Rigid bones are absent ? Very fragileb. Exoskeleton Advantages of exoskeleton? Gives protection and structure to the body? Provides warmth to the body? Provides leverage for the pull of musclesDisadvantages of exoskeleton? Difficult to regulate body temperature? Does not grow so limits the size of organism? Should be repeatedly shed in order to fit the size of animal? Animal are vulnerable during shedding processc. EndoskeletonAdvantages of endoskeleton ? Internally can support great size and weight? Molting is absent? Grows fairly smoothly and evenly? FlexibleDisadvantages of endoskeleton? Less protective found below the soft tissues and muscles? Leverage is worse? Animals are vulnerable to heat, cold and predatorsQuestion 3 (10 minutes, 10 marks)Answer TWO of the following five questions.a. What is the function of a motor neuron? Ans: The function of a motor neuron is to carry an electrical signal to a muscle, triggering it toeither contract or relax. The somatic neurons send signals to the skeletal muscles which help inlocomotion.b. Describe the basic structure of the vertebrate eye. (You may use a diagram.) Ans: Eyes are the organ which detect light and converts it into electro-chemical impulse in theneurons. Many structures work together to facilitate normal vision.The structures of the eye are:1. The orbit: eyes are located in the bony sockets known as orbit. It is surrounded by fattytissues and protects from external impact.2. Extra-ocular muscles: the eyes are attached to the orbit with the help of six muscles thathelp in the movement of eyeball.3. The eye ball: the eye-ball is about 0.9 inches in diameter and is not perfectly round but anablate spheroid.4. The conjunctiva: it is a thin translucent membrane that covers the outer surface of the eyeand the inner surface of the eyelids. The glands in the conjunctiva produce a tear thatlubricates and protects eye while it moves in its sockets.5. The sclera: it is dense, white, fibrous outer protective coat of the eye. It is commonlyknown as the “white of the eye”. 6. The cornea: cornea is a transparent watch glass like structure. Light waves entering theeyes are bent and focused by the cornea. 7. The iris: this is the coloured part of the eye which may be black, blue, green, grey orbrown. The iris contracts or relaxes according to the light in the external environment andadjusts the size of the pupil accordingly.8. The ciliary body: it is a tiny ring like structure present at the base of iris. It helps inchanging the shape of lens. The aqueous humour is secreted by ciliary body, a fluid thatprovides nutrition to the eye.9. The lens: lens is clear, transparent body biconvex, semisolid and shaped like a elongatedsphere. It is located behind the iris and pupil. The main function is fine-tuning of thefocused object.10. The retina: it is a thin film of tissues where images are brought to focus. Retinal have twotypes of cells known as rods and cones which helps to transform the images into signalsand send them to the brain through the optic nerve.11. The optic nerve: this nerve transmits visual information from retina to the brain in the formof signals.Structure of vertebrate eyec. Name one of the glands in the human body that produces a hormone, name the hormoneand briefly describe its function. Ans: Thyroid glands are butter-fly shaped glands present in the base of pharynx region. Thegland has two lobes connected by isthmus in the middle. The gland is rich with blood-vessels.The nerves responsible for voice also pass through the gland. The gland secretes severalhormones collectively known as thyroid hormonesThe thyroid hormones are responsible for growth, metabolism, maintaining body temperature,stimulates the formation of red blood cells to enhance oxygen delivery. Stimulates the activityof other endocrine glands. In children adequate hormone is necessary for normal brain andskeletal muscles development.d. What is a “fixed action pattern” in the study of animal behaviour? Give an example. Ans: Fixed action pattern is an instinctive behavioral response triggered by a specific stimulus.The behavior once triggered cannot be stopped in the middle.Example: Niko Tinbergen, a pioneering researcher of animal behavior, studied the egg rollingbehavior of the Greylag Goose as an example of an FAP. If one of the goosesegg rolls away from the nest, the goose automatically rolls the egg back to the nest with a repeated, specific action.When the female notices an egg outside the nest (sign stimulus), she begins this repeatedmovement to drag the egg with her beak and neck.If, while the goose is rolling the egg back to the nest, the egg slides off to the side, or is removedby an observer, the goose continues to repeat the stereotypic movements, until she reaches thenest. She'll then relocate the missing egg and begin the process all over again.e. Provide an evolutionary explanation for cooperative behaviour among animals of thesame species.Ans:co-operative behavior is used to describe behavior of organisms that are useful to otherorganisms which are selected on that basis. Altruism is one form of co-operative behavior inwhich is explained by kin-selection theory. According to this evolutionary theory theindividuals act co-operatively in order to help other individuals that are genetically similar.The genes for the behavior are preserved in order to perpetuate their own existence. Classicalexamples are ants and bees, where the worker insects never reproduce but they work for thequeen which reproduces.SECTION BUse a separate answer book for this sectionAnswer ALL questions in this section (Q. 4-6)Suggested time for SECTION B: 30 minutesQuestion 4 (10 minutes, 10 marks)Animals are „put together? in a variety of ways. Using appropriate diagrams, provide informationabout animal architecture under these two headings:? pseudocoelomate and coelomate Ans: Pseudocoelomate These animals have pseudocoelome (“false cavity”), it is a fully functional body cavity. Thetissues from the mesoderm partly line the body cavity. The organs are placed loosely and are notfirmly organized as in coelomate. They lack circulatory system and has hydrostatic skeleton.Roundworm is an example of pseudocoelomate.Coelomate The animals have fluid filled body cavity and the cavity is lined by an epithelium that is derivedfrom the mesoderm. The organs are organized and can develop independently. The body wallprovides fluid cushions and protects them from shocks. Vertebrates are example of coelomateanimals. ? bilateral symmetry and radial symmetry Ans: Bilateral symmetry It is also called plane symmetry which has only one plane called the sagittal plane that willdivide the organism into mirror image halves. It will have reflection symmetry. Examples ofbilateral symmetry are butterfly and humans.Radial symmetryIn this symmetry the body it is possible to get identical pieces by cutting at any plane. Theorganisms don?t exhibit left or right sides but have a top and bottom surface only. Examplesstar fish, hydra and flower. Question 5 (10 minutes, 10 marks)Select either the phylum Annelida (earthworms, leeches, fanworms etc) OR the phylumPlatyhelminthes (flatworms, tapeworms, flukes).List the phylum characteristics of the selected group and provide brief comments on the diversity ofthe classes.Ans: Phylum AnnelidaCharacteristic features ? body shows bilateral symmetry and vermiform? body has 2 layers; tissues and organs? the body cavity is true coelom; divided by internal septa? body divided into three regions; a prosomium, a trunk and a pygidium? the nervous system is composed a anterior nerve ring, ganglia and ventral nerve chord? closed circulatory system? no true respiratory organs? feeds on wide range of materials? reproduction is either sexual or hermaphroditeDiversity of classificationThere are three classesClass 1: PolychaetaThis class consists of more than 5,500 species. They are mostly marine habitat, either motile or sessileanimals. Have well developed head and parapodia used for swimming and the body is dorsallyflattened. Most of them are hermaphrodites.Class 2: Oligochaeta This class consists of about 3,100 species of minute worms. They live in both fresh water and brackishwaters. The head is not distinct but had a posterior sucker and pharynx. Body has appendages and arenormally hermaphroditesClass 3: Hirudenea Found in fresh water and moist environment. They are mostly parasitic and also feeds oninvertebrates. Contains more than 500 species and are commonly known as leeches. They show bloodsucking habitats. It has distinct head and the body is divided into segments. Phylum 2: Platyhelmithes Characteristic features ? bilateral symmetry? mostly parasitic? body havelayers of tissues with organs and organelles? no internal body cavity? has a blind gut (no mouth and anus)? lack blood-vascular system? cilia used for locomotion? protonephridial are used as excretory organs? dorsoventrally flattened? reproduction mostly sexual? feeds on smaller life formsDiversity of classificationClass 1: TurbellariaThey are free-living flatworms that are mostly aquatic habitat and few are terrestrial. They are bottom- dwellers. Variable in shape, size and features. Reproduction is asexual (budding) or transverse fission.Has the capacity to regenerate.Class 2: TremetodaThese are parasitic flat worms with oral suckers and sometimes supplemented with hooks that helps inattachment to the hosts. Have well developed digestive system and reproductive system. The life cycleis complex involving two or more hosts. The worms cause serious disease in humans. Example: flukesClass 3: Cestoda The body contains segments and a series of linearly arranged reproductive segments calledproglottids. Mouth and digestive system is absent. Food is absorbed through the cuticle. Head calledscolex is present with oral suckers. Self-fertilization is possible. Example: tapeworms.Class 4: MonogneaMostly external parasites and the fishes and amphibians are the main host of these worms. The adultworms have suckers and hooks and the body is flattened. The pharynx of the worm produces certaindigestive enzymes to digest host skin. They mainly feed on blood and cellular debris.Question 6 (10 minutes, 10 marks)In note form, indicate why insects are considered the most successful of all animal groups.? Insects are more diverse of all animal groups? More number of species are present ? Population number is more? Live in all habitats like desert, forest, grasslands, mountain, ponds, streams, ponds and cities.? Some of them live underground? Most of the insects are less than 1 cm long in shape and form? Have large compound eyes? Huge variety in shape and form? All have three pair of walking legs? These are the fundamental part of the ecosystem? Help in manufacture of useful products like silkSECTION CUse a separate answer book for this sectionAnswer THREE out of the FOUR questions in this section (Q. 7-10) Suggested time forSECTION C: 30 minutesQuestion 7 (10 minutes, 10 marks)Answer ALL parts of this questiona. Draw a diagram showing the normal behaviour of a pair of homologous chromosomes duringmeiosis. b. Explain how an abnormal meiosis can give lead to monosomy or trisomy. Ans: Chromosome abnormalities usually happen as a result of an error in cell division. Meiosis isthe name used to describe the cell division that the egg and sperm undergo when they aredeveloping. Normally, meiosis causes a halving of chromosome material, so that each parent gives23 chromosomes to a pregnancy. The result is an egg or sperm with only 23 chromosomes. When fertilization occurs, the normal 46total number of chromosomes results in the fetus. If meiosis does not occur properly, an egg orsperm could end up with too many chromosomes, or not enough chromosomes. Upon fertilization,the baby could then receive an extra chromosome (called a trisomy), or have a missingchromosome (called a monosomy).Question 8 (10 minutes, 10 marks)Answer ALL parts of this questionWhite coat colour in mice is determined by the recessive c allele and normal coat colour by thedominant C allele. A true-breeding white mouse was crossed with a true-breeding brown mouse.a. What is the expected genotype and phenotype of the F progeny? 1 b. Draw a diagram showing the chromosomes of the F progeny after DNA replication. 1 c. What type of gametes do the F progeny produce? 1 d. What is the expected genotypic ratio in the F ? 2 e. What is the expected phenotypic ratio in the F ? 2 a.ccXCC cCThe expected genotype is cC and the phenotype is brown coat colourb. c. cC and cC are the gametes produced d.cC XcC CCccGenotypic ratio is 1:1e. The phenotypic ratio is 1:1 Question 9 (10 minutes, 10 marks)Answer ALL parts of this questiona. Draw a simple diagram of a nucleotide and explain how nucleotides are joined together toform each strand of a DNA molecule. b. Describe the role of tRNAs in translation. Ans: Transfer RNAs (tRNAs) are small RNA molecules containing 75 to 95 nucleotides tRNA isthe main molecule in translation process as it carries an amino acid on its stem and a 3 nucleotidesequence that is specific for the amino acid in the loop. This is the anticodon which complementsto the sequence present in the DNA. When the tRNA binds to the DNA, the polypeptide to thenewest tRNA again binds to the DNA. The protein is synthesized and the tRNA becomesuncharged after the removal of protein from it. Question 10 (10 minutes, 10 marks)Answer ALL parts of this questiona. Briefly explain how you would go about attempting to produce human insulin in bacteria. Ans: insulin is produced from bacteria using DNA recombinant technology. E.Coli bacteria areused for the production of insulin. The bacterium consists of an extra genetic material calledplasmids. The plasmids are isolated and are cut using restriction endonuclease. Then the humangene producing insulin is inserted into the plasmid and inserted into the bacterium. The bacteriumdivides and produces more number of bacteria along with the gene. Then the human insulin gene isremoved and the insulin is synthesized.b. Describe one method used to create transgenic plants.Ans:the DNA which codes for the protein is selected and is inserted into the plasmid. The plasmidis inserted into the Agrobacterium tumefaciens. Then flowering plants are dipped into the bacteria.Then the bacteria are inserted into plant cell. The selected bacteria form seeds and these seeds aregrown.Section D is on page 54 BIOL110, Semester 12010SECTION DMark your answers to this section on the exam paper.Answer ALL questions in this section (Q. 11-30)Suggested time for SECTION D: 30 minutesCircle the ONE best answer (1.5 minutes/question, 1.5 marks/question)11. Which cellular components are found as part of typical prokaryotic cells? a. Nucleus. b. Mitochondria. c. Ribosomes d. Endoplasmic reticulum e. Chloroplasts Ans: b12. Which of the following are true regarding eukaryotic cells? a. They are always found in multicellular organisms. b. Bacteria are eukaryotes. c. Eukaryotic cells evolved millions of years earlier than prokaryote cells. d. Eukaryotic cells have a variety of membrane bound organelles. e. The name eukaryote means "before nucleus." Ans: a13. The main function of Mitochondria is: a. Energy transduction b. Modification and export of proteins c. Preventing osmotic lysis of the cell d. Photosynthesis e. Synthesis of protein Ans: e14. Which statement about protein synthesis is FALSE? a. Proteins are made by ribosomes. b. All ribosomes making protein are bound to the endoplasmic reticulum. c. Proteins are sent in vesicles from the endoplasmic reticulum to the Golgi. d. The cytoskeleton is used to move vesicles in the secretory pathway. e. Proteins made on the rough ER are coded for by DNA in the nucleus Ans: dThis section continues on the next page.5 BIOL110, Semester 1201015. Golgi bodies are required by eukaryote cells for: a. Synthesis of protein b. Containing the genetic material of the cell c. Photosynthesis d. Modification and export of proteins e. Preventing osmotic lysis of the cell Ans: d16. Match the cytoskeleton component to the description. Microfilaments: a. Provide mechanical stability to animal cells b. Provide tracks for organelle movement. c. Are thin rods made of actin d. Are intermediate sized tubular filaments made of a variety of different proteins e. Are 25nm thick tubular filaments, made of the protein tubulin. Ans: b17. Match the cytoskeleton component to the description. Microtubules: a. Are used for separation of chromosomes during cell division; b. Are found in high concentrations in epithelial cells at the surface of the body c. Are intermediate sized tubular filaments made of a variety of different proteins d. Are thin rods made of actin e. Cause muscle contraction in association with myosin. Ans: a18. Oxygen crosses cell membranes by: a. Simple diffusion b. Active transport c. Facilitated Diffusion d. Endocytosis Ans: a19. If an animal cell (e.g. a red blood cell) is placed in a hypotonic solution: a. Water will flow into the cell causing it to swell and possibly burst. b. A small amount of water will flow into the cell before the cell wall preventsfurther expansion of the cell which becomes pressurised (turgid) c. Water will flow out of the cell causing the cell to shrink. d. There is no substantial flow of water into or out of the cell as the cell membrane isnot permeable to water. Ans: aThis section continues on the next page. BIOL110, Semester 1201020. Which of the following is FALSE? a. The site at which a reaction occurs on an enzyme is called the active site b. The starting material of an enzyme catalysed reaction is called substrate c.Enzymes increase reaction rates by decreasing theG of the reactiond. Free energy is the energy available to do work e. Enzymes lower the activation energy of a reaction. Ans: d21. A metabolic reaction A ? B has a positive free energy change of 20 kJ/mol. Which of thefollowing is required (in addition to substrate A) for the cell to make appreciable amountsof metabolite B a. Enzyme only is required to reduce the large activation energy. b. An enzyme plus ATP is required. c. ATP only is required. d. The reaction would be impossible even with an enzyme and ATP. Ans: c22. Choose the most correct statement regarding glycolysis: a. Glycolysis produces pyruvate, NADH and ATP b. Glycolysis is the first stage in the reduction of glucose c. Glycolysis uses up more ATP than it produces d. Glycolysis uses oxygen and produces carbon dioxide Ans: a23. Which statement about the citric acid cycle is FALSE. a. It produces most of the carbon dioxide from the oxidation of glucose b. It contains 4 oxidation steps. c. The NADH and FADH produced carry energy to the electron transport chain d. It can occur in the absence of oxygen Ans: d24. Which of the following feeds electrons to the electron transport chain? a. oxaloacetate b. carbon dioxide c. oxygen d. NADH e. ATP Ans: dThis section continues on the next page. BIOL110, Semester 1201025. Respiratory ATP production: a. Uses a completely different mechanism to ATP production in chloroplasts. b. Can be directly linked to NADH oxidation because it is a redox reaction. c. Cannot occur in bacteria because they do not have mitochondria. d. Is possible because hydrogen ions cannot cross the lipid bilayer directly bysimple diffusion. Ans: c26. During a sprint (a short burst of strenuous exercise) cells produce lactate because: a. This allows a greater output of ATP per glucose metabolised. b. Cells receive insufficient oxygen to re-oxidise NADH in the electron transport chain. c. Heavy rates of breathing supply excess oxygen to muscle cells. d. The citric acid cycle is highly active. Ans: a27. Photosystem II is a large complex enzyme which: a. Absorbs green light b. Catalyses ATP synthesis. c. Catalyses reduction of NADP+ d. Obtains electrons from water. Ans: a28. Photosystems I and II are both located: a. In green plants and cyanobacteria (blue green algae) b. In the inner envelope membrane of chloroplasts c. In the chloroplast stroma d. In all cells of a plant Ans: b29. The Calvin cycle has the following net equation: a. 3 CO2 + 9 ATP + 6 NADPH ?glyceraldehyde 3-phosphate b. 6 H2O + 6 CO2 ?C6H12O6 + 6 O2 c. 2H2O + 2NADP+ 2 H+ ?O2 + 2NADPH d. Ribulose 1,5-bisphosphate + CO2 ?2x phosphoglycerate Ans: a30. In the disease phenylketonuria: a. The lack of the enzyme phenylalanine hydroxylase causes a reduction inblood phenylalanine. b. Increased tyrosine levels can be detected in a neonatal blood sample. c. Accumulation of phenylalanine causes mental retardation. d. Blood clotting is poorly controlled."