Mitosis Replication of Eukaryotic Cells

Exercise 13MITOSIS REPLICATION OF EUKARYOTIC CELLSANSWERS TO QUESTIONS1.a. Mitosis and cytokinesis atomic offspring 18 oft referred to collectively as cubicleph oneular division. why atomic twist 18 they very much(prenominal) accurately called carrelular counterpunch? The result of mitosis is pperchuction of both cellular telephonephones (repli hombrees) akin to the enhance cell. The genetic stuff and nonsense is replicated rather than divided.b. Does the cell cycle birth a beginning and an land up? The organization of our study of cellular events inti categorices a beginning and end, only when the events pass on to repeat.2.a. If a nucleus has eight chromo both(prenominal)s during interphase, how m either chromosomes does it consider during metaphase? During metaphase thither be 8 double-stranded chromosomes.b. How m either does it sacrifice after(prenominal) mitosis is complete? After mitosis (and separation of chromatids) in that respect argon 1 6 chromosomes distri nonwithstandinged surrounded by both nuclei.3.a. wherefore would we learn an embryologic mass of cells for procedure 13. 3 in which to study the stages of mitosis? embryonic cells atomic number 18 replicating and growing promptlyb. Which stage of mitosis just about often is associated with the beginning of cytokinesis? ordinarily late anaphase4.a. What region of a outset has the around mitotic activity? meristem, fitting to a high place capb. Why is pinching of the cytol s preemptt(p) for cytokinesis in prep atomic number 18 cells? Pinching of cytoplasm is non appropriate for rigid cell walls.c. Locate a plant cell in late telophase. What is the quite a little of the rude(a) cells congress to a mature cell? Each cell is microscopicaler (approximately 1/2) than the p bent cell.5.a. Why ar the combined selective in progress toation from all the class members more(prenominal) meaningful than your results alone? Combined results humble random error.b. How accurate were your predictions for space of severally stage of mitosis? likely not closec. What sources of error offer you disputation for this technique to image the time pass on during to each one stage of mitosis? ariation in onion grow students ability to descry stages microscopic mark sections of roots whitethorn or may not pass finished the thermonuclear 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? peeled genetic combinations allow allowance to changing environss.b. When would it be deleterious? unsanded combinations al expressions produce a percentage of disadvantageous characteristics the risk of incompetent gene combinations may be inappropriate in a stable, ripe environment.2. a.Synapsis eliminates after chromosomal desoxyribonucleic acid has replicated. How legion(pr edicate) chromatids argon involved in crossing-over of a homologic stir upner off of chromosomes?b. Suppose synapsis occurred mingled with two homologous chromosomes, and one had alleles for blue eyeball and brown hair and the early(a) had alleles for blue jet eyes and blonde hair. How m either dissentent combinations of these alleles would be realistic? 4 Remember that crossing-over does not unavoidably occur among the loci, so the real combinations may remain intact. 3. a. If a nucleus has eight chromosomes when it begins pupillary reflex, how some(prenominal) chromosomes does it induct after telophase I? Telophase II? with two chromatids each 4 with one chromatid eachb. What be the major differences amid the events of litotes and mitosis? ( jut out table 14. 2)c. What atomic number 18 some minor differences, and wherefore do you consider them minor? minor differences would be those orthogonal to chromosomal events4. a. During gametogenesis a spermatozoan cell undergoes considerable morphologic change. What are the fundamentals of sperm social organisation and how does it relate to give out? The basics include small train with nucleus an acrosomal process with enzymes to digest the outer(prenominal) membranes of the testis a run and neck rich in mitochondria and buns habituated to propel the cell to the egg.b. What is the advantage of producing sperm in a system of tubes rather than in unharmed tissue? because sperm cells can be expelled easily from the form through a system of tubesc. What is each strand of a double-stranded chromosome called? chromatid5. How would retaining scanty cytoplasm enhance survival of a developing oocyte? More cytoplasm contains more in governectual nourishments to ensure survival.6. a. What are the telling surfaces of oocytes in a abeyant follicle, a growing follicle, and a Graafian follicle? asleep(predicate) oocyte 1X, growing oocyte 5X, mature oocyte 25Xb. ar polar bodies in sight in y our vigilant slide of a cat ovary? Why or why not? likely not, because cells in the ovary usually cod not finished meiosis I, and polar bodies disintegrate rapidly deoxyribonucleic acid FINGERPRINTING LABRestriction Digestion of desoxyribonucleic acid Samples musing QuestionsDescribe the samples of desoxyribonucleic acid (physical properties). The desoxyribonucleic acid samples are clear, color s motiveless liquid samples.Is there whatever observable difference between the samples of deoxyribonucleic acid? no(prenominal) All samples push through connatural.Describe the come out of the closetance of the labour endonuclease mix. The bulwark enzymes appear to be clear, color slight liquids.Restriction Digestion of desoxyribonucleic acid Samples look into QuestionsBefore you incubated your samples, describe any telescopic signs of change in the contents of the tubes containing the desoxyribonucleic acid combined with the prohibition enzymes. desoxyribonucleic acid + Eco RI/PstI enzyme mix no conspicuous change probable(a) in the tubes. nooky you gull any evidence to indicate that your samples of deoxyribonucleic acid were splited or altered in any way by the addition of EcoRI/PstI? Explain. No. No public opinionable change apparent in the tubes.In the absence of visible evidence of change, is it still possible that the DNA samples were confused? Explain your reasoning. Yes. They may be chemically changed but the changes may not be visible. Enzymes may turn over come down the DNA.After a 24 hour incubation period, are there any visible clues that the obstruction enzymes may devour 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 overly small to be try outn.Electrophoresis of Your DNA Samples Review QuestionsThe electrophoresis apparatus creates an galvanizing field positive and forbid ends of the colloidal gel. DNA shreds are negatively charged. To which pole of the electrophoresis field would you expect DNA to reincarnate (+ or -)? Explain. Positive.What color represents the negative pole? Black.After DNA samples are slicked in tumesces, they are squeeze to pre go through the gel matrix. Which sizing fragment (bountiful vs small) would you expect to move toward the opposite end of the gel most quickly? Explain. Smaller. There is less resistance to their travail through the gel matrix.Which fragments are expected to croak the shortest distance remain closest to the wellhead? Explain. Larger. There is more resistance to their presence through the gel matrix.Lesson 4 Thought QuestionsWhat can you assume is contained within each band? DNA fragments.If this were a fingerprint gel, then how many kinds (samples) of DNA can you assume were placed in each separate well? One.What would be a logical comment as to why there is more than one band of DNA for eac h of the samples? The DNA moldiness(prenominal) have been cut into fragments by bulwark enzymes.What believably caused the DNA to cause fragmented? The chemical action of the barricade enzymes cutting at spoticularised base ecological successions.Which of the DNA samples have the kindred number of labor sites for the bar 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? both sites that cut the sample into two fragments.Which DNA samples appear to have been cut into the equivalent number and size of fragments? Lanes 2 and 4 (CS and S2).Based on your abstract 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 s ame individual because they have equal restrictions sites that yield monovular fragments.DNA Fingerprinting OverviewWhat are we trying to de margeine? 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 antithetic 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 give 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 berth. What can you assume is identical about the molecules at that position? The restriction sites are identical.Do any of your mistrustful samples appear to have EcoRI or PstI recognition sit es at the same location as the DNA from the disgust 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 alike banding patterns on the gel.Exercise 23 hatful OF bacteria body politicS ARCHAEBACTERIA AND BACTERIA ANSWERS TO QUESTIONS1. a. Why is it important that bacteria unfreeze nutrients? Nutrients must be released and recycled for use by other vivacious organisms. If nutrients were not released by decomposers, the nutrients would all in conclusion be locked up in dead, non-decaying tissue.b. What term would crush describe heterotrophic bacteria that feed on living tissue? parasitism2. What is the human body and size of each bacterial colony? E. coli long suit rod B. megateriumlarge rod R. rubrumsmall and thin s pirillum 3. a. Which vitrine of bacteria is most familiar in the sample from your teeth? How do you know? in all likelihood yard positive because most of the cells are purpleb. Is barn megaterium gram positive or gram negative? gram positive4. a. Where are the bacteria? ar they between cells or inside cells? inside the cellsb. Why is this relationship between a plant and bacterium called mutualism? two touch offners realise from the association.c. How does Rhizobium make from this association? nutrients from the hostd. How does the host plant benefit from the association? nitrogen return from the bacterium5. Based on their manner, which drugs or chemicals nitwit the growth of bacteria? depends on the drugs that you use6. Do all cells of a trichome of Oscillatoria appear like? yes7. a. Do adjacent cells share a common instance? usuallyb. What do you retrieve is the survive of the sheath? protectionc. Do clusters of Gloeocapsa represent cellular organisms? Why or why not?No, the cells are not stick dependentsthey can operate severally the protoplasms of the cells are not connected the accretion of cells can be miserable into individual cells without killing the cells.8. a. How is the class of Merismopedia varied from other cyanobacteria you canvass in this exercise? Merismopedia is a flat, forthrightly colony one cell four-ply.b. How would a colony attain this bring to pass? equal divisions in two planesExercise 24Survey of Kingdom Protista The Algae ANSWERS TO QUESTIONS1. a. Is the gallery of genus Chlamydomonas smooth or does it appear jerky? congressly smoothb. raise you see both flagella? You may indispensableness to reduce the light intensity level to see flagella. probably not, depends on students microscopec. How does methylcellulose affect doing of Chlamydomonas? slows it downd. How does the sucker help Chlamydomonas run low? feels light2. a. Under what environmental conditions would a zygote not undergo meiosis immed iately? unfavorable conditionsb. atomic number 18 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. quite a little you see any conjunctive tubes? If you cant, envision the prompt slides that demonstrate these structures. probably not seen on live material, but easily seen on nimble materiald. How do you conceptualize that Spirogyra reproduces a internally? mitosis and fragmentation4. a. How is Cladophora morphologically similar to Spirogyra. How is it dissimilar? 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 nonmoti leb. What are the diminutive celestial orbits inside the larger sphere of genus Volvox? daughter coloniesc. How do you suppose they get out? bring up colonies turn inside out or rupture.d. How do you think the number of cells in a young Volvox colony comparisons 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 alga that you have examined earlier in this exercise? Fucus is larger, more parenchymatous, and flattened.b. atomic number 18 all portions of the thallus photosynthetic?How can you tell? probably not, ascribable to different concentrations of blushersc. Considering where Fucus lives, what do you think is the pop off of its gelatinous sheath? Since Fucus lives in intertidal regions, the gelatinous sheath probably prevents desiccation.d. be the swollen structures solid masses or are they empty? essentially empty7.a. Are the gametes of Fucus isogamous or oogamous? oogamousb. How does t he structure of tissue border the reproductive structures compare with that of green algae? Tissues in brown algae are more complex.8. a. hobo you see any pores in the walls of diatoms? robably yesb. Are any of the diatoms pathetic? maybec. If diatoms lack flagella, how do you explain their motility? go on a gelatinous secretiond. How would diatomaceous public compare to sand as a swimming pool slabber material? Which would be get around and why? Diatomaceous earth would be erupt because it is finer. How do the shapes of dinoflagellates compare with other unicellular algae that you have ascertained in this exercise? droll and varied What is the help of the eyespot of Euglena? detect lightExercise 25 review OF KINGDOM PROTISTA PROTOZOA AND SLIME MOLDS ANSWERS TO QUESTIONS1. a. Can you detect moving cytoplasm in the extending pseudopods of ameba? probably yesb. What do you suppose the ameba is moving toward or away from? light or foodc. How does the amoeba respond to nut rient broth? usually increased movementd. some how long would it take an Amoeba to move across the field of view on low proponent? a few minutese. Why is a contractile vacuole of a protozoal often more difficult to see than a food vacuole? A contractile vacuole contains clear excretory fluid, epoch food vacuoles contain particulate matter matter.f. Why would excess pee tend to accumulate in Amoeba? ecause solute concentration in the amoeba is higher than the concentration in the environment and piddle diffuses into the cell2. How could fossilized forams in different geological layers of rock or sediment indicate the probability of purpose anele? 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 vi sible 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 crosswise nuclear 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 the advantages and disadvantages of conjunctive in Paramecium? disadvantages conjugation requires more than one organism and is talent consuming advantage asylum of new genetic combinations6. a. What is the value or function of the rapid condensing drinking straw 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 program line? probably not, but on damp medium they may simply move toward foodc. What is a possible function of cytoplasmic movement in Physarum? avoid light, find foodExercise 26 SURVEY OF KINGDOM FUNGI MOLDS, sacque 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 wampumpeag? 2, 3, or 4b. Do any of the molds on the bread have hyphae modified as sporangiophores and sporangia? probably yesc. Is key distributed uniformly in each mycelium? If not, where is the pigment intemperate in each mold? No, pigment is usually concentrated in sporangia.d. What is the adaptational consequence of spores forming on ends of genuine filaments rather than closer to the overprotective 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 ase xually 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 genus 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? barm 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 unequivocal 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 idea are present on the gills of a single cap of genus Coprinus? Remember that a prepared slide shows only a cross section. many, many thousands8. a. What is the value of phot osynthetic algae to the growth of a fungus in a lichen? Algae abide photosynthesis and produce an energy rich speed of light 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 warm to air pollutionExercise 27 SURVEY OF THE whole kit and boodle 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 disk archegonia are protect under the surface of the archegonial disk.4. a. What is the function of the foot? nutrient dribble from gametophyte to sporophyteb. Are spores haploid or diploid? haploidc. What is the usable signi ficance of the response of elaters to moisture? spreading of spores5. a. How many cells thick is the leaflet? one or twob. Is there a midrib? nervure? 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 pitch 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 regain in the archegonium? egg is enlarge 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 th e condensing 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 separate of the life cycle are haploid? gametophyteb. Which are diploid? sporophyte2.a. How many venas 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 blade? The pinnae? stalksupport blade and pinnaephotosynthesis3.a. What is the function of an annulus? breaking point for theory 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 t he 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 begin 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 from other ferns youve examined earlier? smaller, aquatic8. a. What type of leg 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 genus Equisetum is dominant, the sporophyte or gametophyte? sporophyte10.a. How does strobili formation in Equisetum compare with genus genus 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 raising? produces new growth, which could be set-apart from parent plant (e. g. , via fragmentation), thereby resulting in a new individualb. How is a rhizome different from a rhizoid? hizome is ohmic resistance 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 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 south? yesc. Why are the spores a good, modify lubricant? powdery true 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 rehydrated Selaginella? water conservation and survival during droughtd. Can you see why these plants are sometimes referred to as resurrection plants? yesMitosis Replication of Eukaryotic 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 ge netic 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 are 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 1X, 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, colorless 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 e vidence 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 -)? Explai n. Positive.What color represents the negative pole? Black.After 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 enzyme s cutting at specific base sequences.Which of the DNA samples have 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 c rime 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 bacte ria? 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 cya nobacteria 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 t he chloroplasts of Spirogyra? spiralc. Can you see any conjugation 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 fr om 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 ma terial? 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 conc entration 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 fissio n not a sexual process? it doesnt recombine genesc. What are the 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 ha ve hyphae modified as sporangiophores and sporangia? probably yesc. 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 redu ced 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 (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? an chorage, 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 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 leaflet? 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 towe l? 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? gameto phyteb. 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 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 from 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? hizom e is underground 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 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 rehydrated Selaginella? water conservation and survival during droughtd. Can you see why these plants are sometimes referred to as resurrection plants? yes