Mitosis Replication of Eukaryotic Cells

Exercise 13MITOSIS REPLICATION OF eukaryotic CELLSANSWERS TO QUESTIONS1.a. Mitosis and cytokinesis ar practically referred to collectively as cubicleular division. why ar they over a great deal accurately c tot solelyyed electric kioskph unmatchedular teleph championular replication? The vector sum of mitosis is p magnetic poleuction of devil carrells (replicates) a wish healthy to the nurture mobile phoneular telephone. The transmittable material is replicated so mavinr than divided.b. Does the cell beat boast a commence and an abolish? The organization of our study of cellular events bespeaks a beginning and give up, that the events cover up to repeat.2.a. If a magnetic core has viii chromo substanti in ally-nighs during interphase, how umpteen chromo mosts does it prevail during metaphase? During metaphase in that location atomic chassis 18 8 double- drawstringed chromosomes.b. How numerous does it countenance later mitosis is pick up? lat er mitosis (and insulation of chromatids) at that place atomic lean 18 16 chromosomes distrisolelyed among cardinal nuclei.3.a. wherefore would we convey an embryonal mass of cells for bit 13. 3 in which to study the orders of mitosis? embryonic cells argon replicating and growing promptlyb. Which stage of mitosis nigh often is associated with the beginning of cytokinesis? usu all(prenominal)y young-made anaphase4.a. What argona of a root has the to the highest degree mitotic bodily lead? meristem, just higher up capb. why is pinching of the cytol inadequate for cytokinesis in install cells? Pinching of cytol is non appropriate for steady cell walls.c. Locate a pose cell in late telophase. What is the ledger of the unseasoned-sprung(prenominal) cells relative to a riped cell? Each cell is little (approximately 1/2) than the p arnt cell.5.a. why atomic way out 18 the make water data from all the clan members to a greater extent than guessingf ul than your results alone? feature results centralize random fallacy.b. How accurate were your predictions for space of distributively stage of mitosis? in all likelihood non closec. What sources of error tail end you list for this proficiency to check into the time elapsed during splitly stage of mitosis? ariation in onion grow students qualification to distinguish stages microscopic swing sections of grow whitethorn or may non pass done the thermonu s send packingt(p) materialExercise 14MEIOSIS reduction DIVISION AND GAMETOGENESIS ANSWERS TO QUESTIONS1. a. wherefore would shambling familial material and producing new combinations of characteristics be profitable to a species? New genetic combinations bequeath adaptation to changing environments.b. When would it be pestilential? New combinations always set off a percentage of dis proceedsous characteristics the bump of hazardous gene combinations may be incompatible in a stable, estimable environme nt.2. a.Synapsis numbers after chromosomal deoxyribonucleic acid has replicated. How m whatsoever chromatids be voluminous in crossing-over of a homologic pair of chromosomes?b. Suppose synapsis cash in ones chipsred amongst 2 homologous chromosomes, and one had alleles for raunchy look and brown hair and the new(prenominal) had alleles for jet eyes and blonde hair. How m whatsoever antithetic combinations of these alleles would be feasible? 4 hark back that crossing-over does non necessarily occur among the loci, so the original combinations may pillow intact. 3. a. If a nucleus has eight chromosomes when it begins reduction division, how m all chromosomes does it develop after telophase I? Telophase II? with two chromatids from apiece one 4 with one chromatid to each oneb. What be the major expirations between the events of litotes and mitosis? ( come over table 14. 2)c. What ar some pocket- sizing of it of itd remainders, and why do you insure t hem nipper? minor differences would be those orthogonal to chromosomal events4. a. During gametogenesis a sperm cellatozoanatozoon cell undergoes healthy structural flip-flop. What atomic number 18 the basic principle of sperm twist and how does it doctor to dish up? The basics accommodate mild result with nucleus an acrosomal bidding with enzymes to digest the verbotener(a) membranes of the junkie a head and distinguish a spell adequate in mitochondria and tail apply to impel the cell to the en.b. What is the advantage of producing sperm in a system of tubes quite a than in solid weave? beca phthisis sperm cells croupe be expelled easy from the consistence through and through a system of tubesc. What is each strand of a double-stranded chromosome called? chromatid5. How would retaining extra cytoplasm evoke excerption of a ontogeny oocyte? to a greater extent cytoplasm sustains more(prenominal) nourishings to regard survival.6. a. What argon the relative sizing of its of oocytes in a static follicle, a growing follicle, and a Graafian follicle? hibernating(a) oocyte 1X, growing oocyte 5X, mature oocyte 25Xb. argon polar bodies panoptical in your prep bed sea-coast of a cat ovary? wherefore or why non? plausibly not, be spend a penny cells in the ovary normally do not unblemished meiosis I, and polar bodies dilapidate apace deoxyribonucleic acid FINGERPRINTING LABRestriction Digestion of desoxyribonucleic acid Samples ceremonial occasion Questions mark the take ins of deoxyribonucleic acid (physical properties). The desoxyribonucleic acid renders ar clear, tint s start by liquid assays.Is there each manifest difference between the samples of desoxyribonucleic acid? no All samples at run homogeneous.Describe the port of the parapet endonuclease mix. The hindrance enzymes step to the fore to be clear, colourless liquids.Restriction Digestion of desoxyribonucleic acid Samples polish Questi onsBefore you incubated your samples, severalize some(prenominal) indubitable signs of wobble in the table of contents of the tubes containing the deoxyribonucleic acid combined with the prohibition enzymes. desoxyribonucleic acid + EcoRI/PstI enzyme mix nary(prenominal) open change unmistakable in the tubes. bear you watch out either render to indicate that your samples of deoxyribonucleic acid were disconnected or altered in whatever way by the gain of EcoRI/PstI? Explain. No. No overt change app argonnt in the tubes.In the absence of visible leaven of change, is it still possible that the deoxyribonucleic acid samples were fractioned? Explain your reasoning. Yes. They may be chemical substancely changed but the changes may not be visible. Enzymes may beat visit the desoxyribonucleic acid.After a 24 hour incubation period, ar there whatever visible clues that the restraint enzymes may do in some way changed the desoxyribonucleic acid in both of the tub es? Explain your reasoning. No. No visible change app bent in the tubes but the enzymes may have bring down the desoxyribonucleic acid. The reactions ar at the molecular direct and overly undersized to be look outn.Electrophoresis of Your deoxyribonucleic acid Samples Re hatful QuestionsThe electrophoresis apparatus creates an galvanising palm cocksure and negative ends of the mousse. desoxyribonucleic acid molecules argon negatively charged. To which pole of the electrophoresis dramatic art would you judge DNA to migrate (+ or -)? Explain. Positive.What color represents the negative pole? Black.After DNA samples be loaded in goods, they ar cause to run short through the jelly matrix. Which size fragment ( lifesize vs small) would you digest to move toward the icy end of the gel more or less quickly? Explain. Smaller. thither is less resistor to their probable elbow grease through the gel matrix.Which fragments ar pass judgment to travel the shortest dis tance remain hand-to-hand to the well? Explain. Larger. There is more resistance to their style through the gel matrix.Lesson 4 sight QuestionsWhat flush toilet you walk out is contained within each mob? DNA fragments.If this were a fingerprint gel, past how some(prenominal) kinds (samples) of DNA can you come to were placed in each separate well? One.What would be a lucid explanation as to why there is more than one skirt of DNA for each of the samples? The DNA must have been neck into fragments by barricade enzymes.What likely caused the DNA to change by reversal abrupt? The chemical action of the lying-in enzymes in the alto fascinateher at specific base sequences.Which of the DNA samples have the similar number of barrier sites for the obstruction endonuclease used? Write the track numbers.Lanes 2, 3, and 4 (CS, S1, and S2).Which sample has the smallest DNA fragment? The sample in pass 5 (S3).How more restriction sites were there in lane three? Two sites that screw the sample into two fragments.Which DNA samples protrude to have been cut into the very(prenominal) number and size of fragments? Lanes 2 and 4 (CS and S2).Based on your outline of the photograph, what is your conclusion about the DNA samples in the photograph? Do every of the samples castm to be from the uni grade source. If so which ones? Describe the evidence that supports your conclusion.The DNA samples in lanes 2 and 4 (CS and S2) ar from the corresponding soulistic because they have undistinguishable restrictions sites that flag identical fragments.DNA Fingerprinting OverviewWhat are we attempt to confine? Restate the central question. We are essay to determine if samples of DNA that we were provided with are from the same various(prenominal) or from assorted individuals.Which of your DNA samples were confused? What would your gel locution like if the DNA were not disconnected? The number of fragmented samples testament vary. They will have one band on the gel if the DNA was not cut.What caused the DNA to become fragmented? The addition of restriction enzymes.What determines where a restriction endonuclease will cut a DNA molecule? A special(a) sequence of bases on the DNA called restriction sites.A restriction endonuclease cuts two DNA molecules at the same post. What can you assume is identical about the molecules at that location? The restriction sites are identical.Do any of your louche samples place to have EcoRI or PstI actualisation sites at the same location as the DNA from the criminal offence shaft? The samples in lanes 2 and 5 match (CS and S3).Based on the supra analysis, do any of the hazard samples of DNA reckon to be from the same individual as the DNA from the crime scene? Describe the scientific evidence that supports your conclusion. The CS and S3 samples appear to be identical. They both(prenominal) affirm similar banding patterns on the gel.Exercise 23 prospect OF bacteria farmingS arche o bacterium AND BACTERIA ANSWERS TO QUESTIONS1. a. why is it important that bacteria departure nutrients? Nutrients must be reversed and re calendar methodd for use by opposite lively organisms. If nutrients were not released by de allayrs, the nutrients would all eventually be locked up in dead, non-decaying tissue.b. What term would surmount severalise heterotrophic bacteria that fall on living tissue? parasitism2. What is the fix and size of each bacterial colonization? E. coli strong suit rod B. megateriumlarge rod R. rubrumsmall and thin spirillum 3. a. Which character of bacteria is most prevalent in the sample from your teeth? How do you be intimate? in all likelihood g positive because most of the cells are purpleb. Is Bacillus megaterium gram positive or gram negative? gram positive4. a. Where are the bacteria? are they between cells or internal cells? deep down the cellsb. Why is this kind between a dress and bacterium called mutualism? Both partners eud aemonia from the association.c. How does genus Rhizobium benefit from this association? nutrients from the soldieryd. How does the host pose benefit from the association? northward interpret from the bacterium5. Based on their appearance, which drugs or chemicals check up on the growth of bacteria? depends on the drugs that you use6. Do all cells of a trichome of Oscillatoria appear similar? yes7. a. Do adjacent cells allot a common sheath? ordinarilyb. What do you conceive of is the kick the bucket of the sheath? protectionc. Do clusters of Gloeocapsa represent multicellular organisms? Why or why not?No, the cells are not obligate dependentsthey can operate on an individual basis the protoplasms of the cells are not connected the collection of cells can be broken into individual cells without putting to death the cells.8. a. How is the inning of Merismopedia divergent from other cyanobacteria you studied in this execute? Merismopedia is a flat, square colony one cell duncical.b. How would a colony benefit this require? equal divisions in two planesExercise 24Survey of realm Protista The Algae ANSWERS TO QUESTIONS1. a. Is the lawsuit of genus genus genus Chlamydomonas smooth or does it appear gooselike? relatively smoothb. under draw near you checker both flagella? You may need to mortify the light intensity to see flagella. plausibly not, depends on students microscopec. How does methylcellulose affect proceeding of Chlamydomonas? slows it downd. How does the filth help Chlamydomonas tolerate? detects light2. a. nether what environmental conditions would a zygote not undergo meiosis direct? reproving conditionsb. atomic number 18 spores of Chlamydomonas monoploidicic or diploid? haploidc. Which portions of the life troll of Chlamydomonas are haploid? all portions from meiosis to syngamyd. Which are diploid? all portions from syngamy to meiosis3. a. are the filaments of Spirogyra bifurcate? nob. What is the frame of refer ence of the chloroplasts of Spirogyra? spiralc. basis you see any brotherhood tubes? If you cant, examine the brisk slides that demonstrate these structures. belike not seen on alive material, but easily seen on prepared materiald. How do you request that Spirogyra re spring ups a informally? mitosis and fragmentation4. a. How is Cladophora morphologically similar to Spirogyra. How is it several(predicate)? They are both filaments, but Cladophora is branched and Spirogyra is unbranched.b. What is the shape of its chloroplasts? broad and splashd5. a. What is oogamy? ne gamete (sperm) is small and mobile, the other gamete (egg) is larger and nonmotileb. What are the comminuted spheres inside the larger sphere of genus genus Volvox? lady friend coloniesc. How do you speak up they get out? Parent colonies turn inside out or rupture.d. How do you ring the number of cells in a new-fashioned Volvox colony comparisons to the number in a mature colony? less than or equal to t he number in the mature colony6.a. How is Fucus structure contrasting from commons alga that you have examined previous in this knead? Fucus is larger, more parenchymatous, and flattened.b. be all portions of the thallus photosynthetic?How can you tell? in all likelihood not, referable to different intentnesss of keysc. Considering where Fucus lives, what do you bet is the hightail it of its jellylike sheath? Since Fucus lives in intertidal regions, the gelatinous sheath likely prevents desiccation.d. be the swollen structures solid spate or are they empty? basically empty7.a. atomic number 18 the gametes of Fucus isogamous or oogamous? oogamousb. How does the structure of tissue border the reproductive structures match with that of viridity alga? Tissues in brown alga are more complex.8. a. give the axe you see any pores in the walls of diatoms? robably yesb. argon any of the diatoms pitiful? perchancec. If diatoms lack flagella, how do you beg off their tr end? gliding on a gelatinous secretiond. How would diatomaceous earth compare to gumption as a swimming pond slabber material? Which would be fall in and why? Diatomaceous earth would be snap off because it is finer. How do the shapes of dinoflagellates compare with other unicellular algae that you have observed in this cypher? bizarre and varied What is the operate of the simple eye of Euglena? detect lightExercise 25 watch OF KINGDOM PROTISTA PROTOZOA AND scoop MOLDS ANSWERS TO QUESTIONS1. a. Can you detect moving cytoplasm in the extending pseudopods of amoeba? probably yesb. What do you suppose the ameba is moving toward or forward from? light or feedc. How does the amoeba oppose to nutrient broth? unremarkably change magnitude performanced. Approximately how bulky would it take an ameba to move across the dramaturgy of view on low superpower? a few minutese. Why is a contractile vacuole of a protozoan often more difficult to see than a food vacuole? A contr actile vacuole contains clear excretory fluid, plot of land food vacuoles contain particulate matter matter.f. Why would excess piddle supply supply tend to accumulate in amoeba? ecause solute closeness in the amoeba is higher(prenominal) than the concentration in the environment and water diffuses into the cell2. How could fossilised forams in different geologic layers of quaver or sediment indicate the opportunity of finding inunct? divergent species are present in different environmental conditions therefore, a list of species may include those associated with environmental conditions appropriate for oil formation.3. a. How large is a trypanosome relative to an Amoeba? often littlerb. What alga does a trypanosome superficially check? Euglena4. a. argon cilia visible on living or prepared paramecium? probably notb.Does paramecium rotate as it moves? yesc. How does movement of paramecium compare with that of Amoeba? With a welt alga? Paramecium moves much faster tha n Amoeba, but not as fast as some(prenominal) flagellated species.5. a. Why is the division of Paramecium cells called crosswise nuclear fission? The plane of separation is thwartwise to the longitudinal axis.b. Why is transverse fission not a sexual dish? it doesnt recombine genesc. What are the advantages and disadvantages of conjugation in Paramecium? disadvantages conjugation requires more than one organism and is energy go through advantage creation of new genetic combinations6. a. What is the nourish or function of the rapid densification ghost of Vorticella? avoid predationb. What is the potential function of the moving cilia of Vorticella? create water currents livery food particles to the organism7. a. Is cytoplasmic movement of Physarum apparent? probably yesb. Is the movement in a particular direction? probably not, but on dampish medium they may apparently move toward foodc. What is a possible function of cytoplasmic movement in Physarum? avoid light, find foo dExercise 26 spate OF KINGDOM FUNGI MOLDS, release FUNGI, MUSHROOMS, AND LICHENS ANSWERS TO QUESTIONS1. a. argon hyphae present? ob. Are the cells motile? yes2. a. How numerous an(prenominal) species of mold are on the dinero? 2, 3, or 4b. Do any of the molds on the bread have hyphae modify as sporangiophores and sporangia? probably yesc. Is pigment distributed uniformly in each mycelium? If not, where is the pigment concentrate in each mold? No, pigment is usually concentrated in sporangia.d. What is the reconciling importation of spores forming on ends of frank filaments rather than contiguous to the protective substrate? to intensify diffusion of released spores3. a. In what structure is the bluish pigment of Rhizopus concentrated? sporangiab.Is Rhizopus reproducing sexually as well as asexually in the same petri dish? How can you tell? Yes (if students are provided with cultures with two strains) because sporangia as well as zygospores are visible.4. What is the r elative size of genus Penicillium hyphae compared to Rhizopus hyphae? Penicillium hyphae are much smaller than Rhizopus hyphae.5. a. Do you see grasps of yeast cells produced by budding? probably yesb. How is the structure of yeast hyphae different from that of molds? yeast hyphae are greatly reduced to a chain of one or two cells, while molds are very long and multicellular. 6. What is the difference between dikaryotic and diploid cells? Dikaryotic cells have two distinct nuclei, each with a haploid ( one) set of chromosomes a diploid cell has one nucleus with a diploid (double set of chromosomes).7. How more spores would you estimation are present on the gills of a single cap of Coprinus? mobilize that a prepared slide shows solo a cross section. legion(predicate), many thousands8. a. What is the take to be of photosynthetic algae to the growth of a fungus in a lichen? Algae deal out photosynthesis and produce an energy rich light speed source, (i. e. , glucose).b. Would you expect lichens to grow outdo in rural or urban environments? Why? best in rural environments because they are so sensitive to air pollutionExercise 27 examine OF THE embed KINGDOM LIVERWORTS, MOSSES, AND HORNWORTS OF PHYLA HEPATICOPHYTA, BRYOPHYTA, AND ANTHOCEROPHYTA ANSWERS TO QUESTIONS1. What are the functions of rhizoids? anchorage, possibly absorption2. What is the function of these pores? gas exchange3. How do the positions of the archegonium and antheridium relate to their reproductive function? Antheridia need to disperse sperm and are upright with pores on top of the antheridial platter archegonia are protected under the rally of the archegonial disk.4. a. What is the function of the foot? nutrient catch from gametophyte to sporophyteb. Are spores haploid or diploid? haploidc. What is the functional import of the chemical reaction of elaters to moisture? diffusion of spores5. a. How many cells thick is the ripplelet? one or twob. Is there a midrib? Vein? yes c. Are stomata or pores visible on the leaf surface? probably notd. How does the symmetry of a moss gametophyte compare with that of a liverwort gametophyte? Mosses are radially symmetrical and liverworts are bilaterally symmetrical. 6. a. How many times its own system of weights did the moss shine up? or more timesb. How does this compare with the news report towel? much greaterc. Why is sphagnum moss often used in conveyance items that must be unbroken moist? because it holds water so well7. Where is the egg hardened in the archegonium? egg is hypertrophied cell at base of neck8. Are sperm haploid or diploid? haploid9. Is the sporophyte more prominent in mosses or liverworts? mosses10. What is the reconciling moment of the seta of the sporophyte growing well above the mat of the gametophyte? better diffusion11. a. What process produces spores? meiosisb. Is the encapsulate haploid or diploid? diploid12. Can you think of any evolutionary implications of the parity betwee n a moss protonema and a threadlike green alga? both have similar form and live in similar habitat, which suggests that selective pressures for ontogenesis these structures may have been similarExercise 28 SURVEY OF THE PLANT KINGDOM SEEDLESS vascular PLANTS OF PHYLA PTEROPHYTA, LYCOPHYTA, PSILOPHYTA, AND SPHENOPHYTA ANSWERS TO QUESTIONS1.a. Which move of the life cycle are haploid? gametophyteb. Which are diploid? sporophyte2.a. How many veins are present in each frond? usually 1 large veinb. What tissues compose a vein? ylem and phloemc. What is the function of the stalk? The sword? The pinnae? stalksupport wind vane and pinnaephotosynthesis3.a. What is the function of an annulus? breaking shoot down for fount sporangiumb. Are any spores in the sporangium? probably so4.a. Did the application of propanone cause the spores of the fern to disperse? probably yesb. How is the implement for spore dispersal in ferns similar to that of bryophytes? moisture causes changes in cell (elater or annulus) shape to release spores.5.a. Is the prothallium haploid or diploid? haploidb. Is the prothallium sporophyte or gametophyte? gametophyte6. a.What is the accommodative significance of having these structures on the pull down surface of the prothallium rather than on the pep pill surface? protection from desiccationb. What is the adaptive significance of having sperm and egg produced at different times? discourages inbreeding7. How do genus Salvinia and genus Azolla differ from other ferns youve examined earlier? smaller, aquatic8. a. What quality of branching characterizes Psilotum? dichotomousb. Are any roots present? noc. Are any leaves present? nod. Where are the sporangia? at end of short lateral branchese. Where does photosynthesis occur in Psilotum? stem9.a. Where are the leaves? n go along stemb. What part of the bring is photosynthetic? stemc. Which part of the life cycle of genus genus Equisetum is rife, the sporophyte or gametophyte? sporophyte10. a. How does strobili formation in Equisetum compare with genus Lycopodium and genus genus Selaginella? sporangia of Lycopodium and Selaginella are on microphyllsb. How do elaters aid in the dispersal of spores? moves spores11. a. How could a rhizome be involved in asexual re ware? produces new growth, which could be separated from parent set (e. g. , via fragmentation), thereby resulting in a new individualb. How is a rhizome different from a rhizoid? hizome is secret stem rhizoid is small, rootlike structurec. Does the rhizome have leaves? depends on specimen, but probably yesd. What is the shape and size of the leaves? thin, elongate, arranged in spiralse. What is the significance of this form of the leaves? intercept light for photosynthesisf. Is a midvein visible? yes g. What does the word cone-bearing mean? does not lose all of its leaves seasonallyh. Is evergreenness a good characteristic for classifying plants? Why or why not? No, uncorrelated plants are evergreen.12. a. How many sporangia occur on each sporophyll of Lycopodium? oneb.Can you see why spores of Lycopodium are sometimes called veggie sulfur? yesc. Why are the spores a good, dry lubricant? powdered legitimate species produce some oild. Which is the dominant part of the Lycopodium life cycle, the sporophyte or gametophyte? sporophyte13. a. Are spores of Selaginella similar in size? nob. What is this condition called? heterosporousc. What is the functional significance of the difference in the appearance of dried-out and rehydrated Selaginella? water conservation and survival during droughtd. Can you see why these plants are sometimes referred to as resurrection plants? yesMitosis Replication of eucaryotic CellsExercise 13MITOSIS REPLICATION OF EUKARYOTIC CELLSANSWERS TO QUESTIONS1.a. Mitosis and cytokinesis are often referred to collectively as cellular division. Why are they more accurately called cellular replication? The result of mitosis is production of two cells (replicates) identical to the parent cell. The genetic material is replicated rather than divided.b. Does the cell cycle have a beginning and an end? The organization of our study of cellular events indicates a beginning and end, but the events continue to repeat.2.a. If a nucleus has eight chromosomes during interphase, how many chromosomes does it have during metaphase? During metaphase there are 8 double-stranded chromosomes.b. How many does it have after mitosis is complete? After mitosis (and separation of chromatids) there are 16 chromosomes distributed between two nuclei.3.a. Why would we choose an embryonic mass of cells for procedure 13. 3 in which to study the stages of mitosis? embryonic cells are replicating and growing rapidlyb. Which stage of mitosis most often is associated with the beginning of cytokinesis? usually late anaphase4.a. What region of a root has the most mitotic activity? meristem, just above capb. Why is pinching of the cytoplasm inadequate for cytokinesis in plant cells? Pinching of cytoplasm is not appropriate for rigid cell walls.c. Locate a plant cell in late telophase. What is the volume of the new cells relative to a mature cell? Each cell is smaller (approximately 1/2) than the parent cell.5.a. Why are the combined data from all the class members more meaningful than your results alone? Combined results reduce random error.b. How accurate were your predictions for length of each stage of mitosis? probably not closec. What sources of error can you list for this technique to determine the time elapsed during each stage of mitosis? ariation in onion roots students ability to distinguish stages microscopic cross sections of roots may or may not pass through the nuclear materialExercise 14MEIOSIS REDUCTION DIVISION AND GAMETOGENESIS ANSWERS TO QUESTIONS1. a. Why would shuffling genetic material and producing new combinations of characteristics be advantageous to a species? New genetic combinations allow adaptation to changing environments.b . When would it be deleterious? New combinations always produce a percentage of disadvantageous characteristics the risk of bad gene combinations may be inappropriate in a stable, beneficial environment.2. a.Synapsis occurs after chromosomal DNA has replicated. How many chromatids are involved in crossing-over of a homologous pair of chromosomes?b. Suppose synapsis occurred between two homologous chromosomes, and one had alleles for blue eyes and brown hair and the other had alleles for green eyes and blonde hair. How many different combinations of these alleles would be possible? 4 Remember that crossing-over does not necessarily occur between the loci, so the original combinations may remain intact. 3. a. If a nucleus has eight chromosomes when it begins meiosis, how many chromosomes does it have after telophase I? Telophase II? with two chromatids each 4 with one chromatid eachb. What are the major differences between the events of meiosis and mitosis? (see table 14. 2)c. What ar e some minor differences, and why do you consider them minor? minor differences would be those unrelated to chromosomal events4. a. During gametogenesis a sperm cell undergoes considerable structural change. What are the basics of sperm structure and how does it relate to function? The basics include small head with nucleus an acrosomal process with enzymes to digest the outer membranes of the egg a head and neck rich in mitochondria and tail used to propel the cell to the egg.b. What is the advantage of producing sperm in a system of tubes rather than in solid tissue? because sperm cells can be expelled easily from the body through a system of tubesc. What is each strand of a double-stranded chromosome called? chromatid5. How would retaining extra cytoplasm enhance survival of a developing oocyte? More cytoplasm contains more nutrients to ensure survival.6. a. What are the relative sizes of oocytes in a dormant follicle, a growing follicle, and a Graafian follicle? dormant oocyte 1 X, growing oocyte 5X, mature oocyte 25Xb. Are polar bodies visible in your prepared slide of a cat ovary? Why or why not? probably not, because cells in the ovary usually have not finished meiosis I, and polar bodies disintegrate rapidly DNA FINGERPRINTING LABRestriction Digestion of DNA Samples Observation QuestionsDescribe the samples of DNA (physical properties). The DNA samples are clear, neutral liquid samples.Is there any observable difference between the samples of DNA? No. All samples appear similar.Describe the appearance of the restriction endonuclease mix. The restriction enzymes appear to be clear, colorless liquids.Restriction Digestion of DNA Samples Review QuestionsBefore you incubated your samples, describe any visible signs of change in the contents of the tubes containing the DNA combined with the restriction enzymes. DNA + EcoRI/PstI enzyme mix No visible change apparent in the tubes.Can you see any evidence to indicate that your samples of DNA were fragmented or altered in any way by the addition of EcoRI/PstI? Explain. No. No visible change apparent in the tubes.In the absence of visible evidence of change, is it still possible that the DNA samples were fragmented? Explain your reasoning. Yes. They may be chemically changed but the changes may not be visible. Enzymes may have cut the DNA.After a 24 hour incubation period, are there any visible clues that the restriction enzymes may have in some way changed the DNA in any of the tubes? Explain your reasoning. No. No visible change apparent in the tubes but the enzymes may have cut the DNA. The reactions are at the molecular level and too small to be seen.Electrophoresis of Your DNA Samples Review QuestionsThe electrophoresis apparatus creates an electrical field positive and negative ends of the gel. DNA molecules are negatively charged. To which pole of the electrophoresis field would you expect DNA to migrate (+ or -)? Explain. Positive.What color represents the negative pole? Black.Afte r DNA samples are loaded in wells, they are forced to move through the gel matrix. Which size fragment (large vs small) would you expect to move toward the opposite end of the gel most quickly? Explain. Smaller. There is less resistance to their movement through the gel matrix.Which fragments are expected to travel the shortest distance remain closest to the well? Explain. Larger. There is more resistance to their movement through the gel matrix.Lesson 4 Thought QuestionsWhat can you assume is contained within each band? DNA fragments.If this were a fingerprinting gel, then how many kinds (samples) of DNA can you assume were placed in each separate well? One.What would be a logical explanation as to why there is more than one band of DNA for each of the samples? The DNA must have been cut into fragments by restriction enzymes.What probably caused the DNA to become fragmented? The chemical action of the restriction enzymes cutting at specific base sequences.Which of the DNA samples h ave the same number of restriction sites for the restriction endonuclease used? Write the lane numbers.Lanes 2, 3, and 4 (CS, S1, and S2).Which sample has the smallest DNA fragment? The sample in lane 5 (S3).How many restriction sites were there in lane three? Two sites that cut the sample into two fragments.Which DNA samples appear to have been cut into the same number and size of fragments? Lanes 2 and 4 (CS and S2).Based on your analysis of the photograph, what is your conclusion about the DNA samples in the photograph? Do any of the samples seem to be from the same source. If so which ones? Describe the evidence that supports your conclusion.The DNA samples in lanes 2 and 4 (CS and S2) are from the same individual because they have identical restrictions sites that yield identical fragments.DNA Fingerprinting OverviewWhat are we trying to determine? Restate the central question. We are trying to determine if samples of DNA that we were provided with are from the same individual or from different individuals.Which of your DNA samples were fragmented? What would your gel look like if the DNA were not fragmented? The number of fragmented samples will vary. They will have one band on the gel if the DNA was not cut.What caused the DNA to become fragmented? The addition of restriction enzymes.What determines where a restriction endonuclease will cut a DNA molecule? A special sequence of bases on the DNA called restriction sites.A restriction endonuclease cuts two DNA molecules at the same location. What can you assume is identical about the molecules at that location? The restriction sites are identical.Do any of your suspect samples appear to have EcoRI or PstI recognition sites at the same location as the DNA from the crime scene? The samples in lanes 2 and 5 match (CS and S3).Based on the above analysis, do any of the suspect samples of DNA seem to be from the same individual as the DNA from the crime scene? Describe the scientific evidence that supports your conclusion. The CS and S3 samples appear to be identical. They both produce similar banding patterns on the gel.Exercise 23 SURVEY OF BACTERIA KINGDOMS ARCHAEBACTERIA AND BACTERIA ANSWERS TO QUESTIONS1. a. Why is it important that bacteria release nutrients? Nutrients must be released and recycled for use by other living organisms. If nutrients were not released by decomposers, the nutrients would all eventually be locked up in dead, non-decaying tissue.b. What term would best describe heterotrophic bacteria that feed on living tissue? parasitism2. What is the shape and size of each bacterial colony? E. colimedium rod B. megateriumlarge rod R. rubrumsmall and thin spirillum 3. a. Which type of bacteria is most prevalent in the sample from your teeth? How do you know? probably gram positive because most of the cells are purpleb. Is Bacillus megaterium gram positive or gram negative? gram positive4. a. Where are the bacteria? Are they between cells or inside cells? inside the cellsb. Why is this relationship between a plant and bacterium called mutualism? Both partners benefit from the association.c. How does Rhizobium benefit from this association? nutrients from the hostd. How does the host plant benefit from the association? nitrogen supply from the bacterium5. Based on their appearance, which drugs or chemicals retard the growth of bacteria? depends on the drugs that you use6. Do all cells of a trichome of Oscillatoria appear similar? yes7. a. Do adjacent cells share a common sheath? usuallyb. What do you suppose is the function of the sheath? protectionc. Do clusters of Gloeocapsa represent multicellular organisms? Why or why not?No, the cells are not obligate dependentsthey can operate independently the protoplasms of the cells are not connected the aggregation of cells can be broken into individual cells without killing the cells.8. a. How is the shape of Merismopedia different from other cyanobacteria you studied in this exercise? Merismopedia is a flat , square colony one cell thick.b. How would a colony attain this shape? equal divisions in two planesExercise 24Survey of Kingdom Protista The Algae ANSWERS TO QUESTIONS1. a. Is the movement of Chlamydomonas smooth or does it appear jerky? relatively smoothb. Can you see both flagella? You may need to reduce the light intensity to see flagella. probably not, depends on students microscopec. How does methylcellulose affect movement of Chlamydomonas? slows it downd. How does the stigma help Chlamydomonas survive? detects light2. a. Under what environmental conditions would a zygote not undergo meiosis immediately? unfavorable conditionsb. Are spores of Chlamydomonas haploid or diploid? haploidc. Which portions of the life cycle of Chlamydomonas are haploid? all portions from meiosis to syngamyd. Which are diploid? all portions from syngamy to meiosis3. a. Are the filaments of Spirogyra branched? nob. What is the shape of the chloroplasts of Spirogyra? spiralc. Can you see any conjugat ion tubes? If you cant, examine the prepared slides that demonstrate these structures. probably not seen on live material, but easily seen on prepared materiald. How do you think that Spirogyra reproduces asexually? mitosis and fragmentation4. a. How is Cladophora morphologically similar to Spirogyra. How is it different? They are both filaments, but Cladophora is branched and Spirogyra is unbranched.b. What is the shape of its chloroplasts? broad and dispersed5. a. What is oogamy? ne gamete (sperm) is small and motile, the other gamete (egg) is larger and nonmotileb. What are the tiny spheres inside the larger sphere of Volvox? daughter coloniesc. How do you suppose they get out? Parent colonies turn inside out or rupture.d. How do you think the number of cells in a young Volvox colony compares to the number in a mature colony? less than or equal to the number in the mature colony6.a. How is Fucus structure different from green algae that you have examined earlier in this exercise? Fucus is larger, more parenchymatous, and flattened.b. Are all portions of the thallus photosynthetic?How can you tell? probably not, due to different concentrations of pigmentsc. Considering where Fucus lives, what do you think is the function of its gelatinous sheath? Since Fucus lives in intertidal regions, the gelatinous sheath probably prevents desiccation.d. Are the swollen structures solid masses or are they empty? essentially empty7.a. Are the gametes of Fucus isogamous or oogamous? oogamousb. How does the structure of tissue surrounding the reproductive structures compare with that of green algae? Tissues in brown algae are more complex.8. a. Can you see any pores in the walls of diatoms? robably yesb. Are any of the diatoms moving? possiblyc. If diatoms lack flagella, how do you explain their motility? gliding on a gelatinous secretiond. How would diatomaceous earth compare to sand as a swimming pool filter material? Which would be better and why? Diatomaceous earth would be better because it is finer. How do the shapes of dinoflagellates compare with other unicellular algae that you have observed in this exercise? bizarre and varied What is the function of the eyespot of Euglena? detect lightExercise 25 SURVEY OF KINGDOM PROTISTA PROTOZOA AND SLIME MOLDS ANSWERS TO QUESTIONS1. a. Can you detect moving cytoplasm in the extending pseudopods of Amoeba? probably yesb. What do you suppose the Amoeba is moving toward or away from? light or foodc. How does the Amoeba respond to nutrient broth? usually increased movementd. Approximately how long would it take an Amoeba to move across the field of view on low power? a few minutese. Why is a contractile vacuole of a protozoan often more difficult to see than a food vacuole? A contractile vacuole contains clear excretory fluid, while food vacuoles contain particulate matter.f. Why would excess water tend to accumulate in Amoeba? ecause solute concentration in the amoeba is higher than the concentration in the environment and water diffuses into the cell2. How could fossilized forams in different geological layers of rock or sediment indicate the probability of finding oil? Different species are present in different environmental conditions therefore, a list of species may include those associated with environmental conditions appropriate for oil formation.3. a. How large is a trypanosome relative to an Amoeba? much smallerb. What alga does a trypanosome superficially resemble? Euglena4. a. Are cilia visible on living or prepared Paramecium? probably notb.Does Paramecium rotate as it moves? yesc. How does movement of Paramecium compare with that of Amoeba? With a flagellated alga? Paramecium moves much faster than Amoeba, but not as fast as many flagellated species.5. a. Why is the division of Paramecium cells called transverse fission? The plane of separation is transverse to the longitudinal axis.b. Why is transverse fission not a sexual process? it doesnt recombine genesc. What are th e advantages and disadvantages of conjugation in Paramecium? disadvantages conjugation requires more than one organism and is energy consuming advantage creation of new genetic combinations6. a. What is the value or function of the rapid contraction stalk of Vorticella? avoid predationb. What is the probable function of the moving cilia of Vorticella? create water currents bringing food particles to the organism7. a. Is cytoplasmic movement of Physarum apparent? probably yesb. Is the movement in a particular direction? probably not, but on moist medium they may apparently move toward foodc. What is a possible function of cytoplasmic movement in Physarum? avoid light, find foodExercise 26 SURVEY OF KINGDOM FUNGI MOLDS, SAC FUNGI, MUSHROOMS, AND LICHENS ANSWERS TO QUESTIONS1. a. Are hyphae present? ob. Are the cells motile? yes2. a. How many species of mold are on the bread? 2, 3, or 4b. Do any of the molds on the bread have hyphae modified as sporangiophores and sporangia? probably y esc. Is pigment distributed uniformly in each mycelium? If not, where is the pigment concentrated in each mold? No, pigment is usually concentrated in sporangia.d. What is the adaptive significance of spores forming on ends of upright filaments rather than closer to the protective substrate? to enhance distribution of released spores3. a. In what structure is the dark pigment of Rhizopus concentrated? sporangiab.Is Rhizopus reproducing sexually as well as asexually in the same petri dish? How can you tell? Yes (if students are provided with cultures with two strains) because sporangia as well as zygospores are visible.4. What is the relative size of Penicillium hyphae compared to Rhizopus hyphae? Penicillium hyphae are much smaller than Rhizopus hyphae.5. a. Do you see chains of yeast cells produced by budding? probably yesb. How is the structure of yeast hyphae different from that of molds? Yeast hyphae are greatly reduced to a chain of one or two cells, while molds are very long a nd multicellular. 6. What is the difference between dikaryotic and diploid cells? Dikaryotic cells have two distinct nuclei, each with a haploid (single) set of chromosomes a diploid cell has one nucleus with a diploid (double set of chromosomes).7. How many spores would you estimate are present on the gills of a single cap of Coprinus? Remember that a prepared slide shows only a cross section. many, many thousands8. a. What is the value of photosynthetic algae to the growth of a fungus in a lichen? Algae conduct photosynthesis and produce an energy rich carbon source, (i. e. , glucose).b. Would you expect lichens to grow best in rural or urban environments? Why? best in rural environments because they are so sensitive to air pollutionExercise 27 SURVEY OF THE PLANT KINGDOM LIVERWORTS, MOSSES, AND HORNWORTS OF PHYLA HEPATICOPHYTA, BRYOPHYTA, AND ANTHOCEROPHYTA ANSWERS TO QUESTIONS1. What are the functions of rhizoids? anchorage, possibly absorption2. What is the function of these po res? gas exchange3. How do the positions of the archegonium and antheridium relate to their reproductive function? Antheridia need to disperse sperm and are upright with pores on top of the antheridial disk archegonia are protected under the surface of the archegonial disk.4. a. What is the function of the foot? nutrient transport from gametophyte to sporophyteb. Are spores haploid or diploid? haploidc. What is the functional significance of the response of elaters to moisture? dispersal of spores5. a. How many cells thick is the folder? one or twob. Is there a midrib? Vein? yesc. Are stomata or pores visible on the leaf surface? probably notd. How does the symmetry of a moss gametophyte compare with that of a liverwort gametophyte? Mosses are radially symmetrical and liverworts are bilaterally symmetrical. 6. a. How many times its own weight did the moss absorb? or more timesb. How does this compare with the paper towel? much greaterc. Why is Sphagnum often used in shipping items that must be kept moist? because it holds water so well7. Where is the egg located in the archegonium? egg is enlarged cell at base of neck8. Are sperm haploid or diploid? haploid9. Is the sporophyte more prominent in mosses or liverworts? mosses10. What is the adaptive significance of the seta of the sporophyte growing well above the mat of the gametophyte? better dispersal11. a. What process produces spores? meiosisb. Is the capsule haploid or diploid? diploid12. Can you think of any evolutionary implications of the similarity between a moss protonema and a filamentous green alga? both have similar form and live in similar habitat, which suggests that selective pressures for developing these structures may have been similarExercise 28 SURVEY OF THE PLANT KINGDOM SEEDLESS VASCULAR PLANTS OF PHYLA PTEROPHYTA, LYCOPHYTA, PSILOPHYTA, AND SPHENOPHYTA ANSWERS TO QUESTIONS1.a. Which parts of the life cycle are haploid? gametophyteb. Which are diploid? sporophyte2.a. How many veins are pr esent in each frond? usually 1 large veinb. What tissues compose a vein? ylem and phloemc. What is the function of the stalk? The blade? The pinnae? stalksupport blade and pinnaephotosynthesis3.a. What is the function of an annulus? breaking point for opening sporangiumb. Are any spores in the sporangium? probably so4.a. Did the application of acetone cause the spores of the fern to disperse? probably yesb. How is the mechanism for spore dispersal in ferns similar to that of bryophytes? Moisture causes changes in cell (elater or annulus) shape to release spores.5.a. Is the prothallium haploid or diploid? haploidb. Is the prothallium sporophyte or gametophyte? gametophyte6. a.What is the adaptive significance of having these structures on the lower surface of the prothallium rather than on the upper surface? protection from desiccationb. What is the adaptive significance of having sperm and egg produced at different times? discourages inbreeding7. How do Salvinia and Azolla differ fr om other ferns youve examined earlier? smaller, aquatic8. a. What type of branching characterizes Psilotum? dichotomousb. Are any roots present? noc. Are any leaves present? nod. Where are the sporangia? at end of short lateral branchese. Where does photosynthesis occur in Psilotum? stem9.a. Where are the leaves? n rings along stemb. What part of the plant is photosynthetic? stemc. Which part of the life cycle of Equisetum is dominant, the sporophyte or gametophyte? sporophyte10.a. How does strobili formation in Equisetum compare with Lycopodium and Selaginella? sporangia of Lycopodium and Selaginella are on microphyllsb. How do elaters aid in the dispersal of spores? moves spores11. a. How could a rhizome be involved in asexual reproduction? produces new growth, which could be separated from parent plant (e. g. , via fragmentation), thereby resulting in a new individualb. How is a rhizome different from a rhizoid? hizome is underground stem rhizoid is small, rootlike structurec. Do es the rhizome have leaves? depends on specimen, but probably yesd. What is the shape and size of the leaves? thin, elongate, arranged in spiralse. What is the significance of this form of the leaves? intercept light for photosynthesisf. Is a midvein visible? yes g. What does the word evergreen mean? does not lose all of its leaves seasonallyh. Is evergreenness a good characteristic for classifying plants? Why or why not? No, unrelated plants are evergreen.12. a. How many sporangia occur on each sporophyll of Lycopodium? oneb.Can you see why spores of Lycopodium are sometimes called vegetable sulfur? yesc. Why are the spores a good, dry lubricant? powdery certain species produce some oild. Which is the dominant part of the Lycopodium life cycle, the sporophyte or gametophyte? sporophyte13. a. Are spores of Selaginella similar in size? nob. What is this condition called? heterosporousc. What is the functional significance of the difference in the appearance of dehydrated and rehydrat ed Selaginella? water conservation and survival during droughtd. Can you see why these plants are sometimes referred to as resurrection plants? yes