transport of materials in flowering plants

8/13/2019 Transport of Materials in Flowering Plants

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Name: Class

Transport of Materials in lowering PlantsInvestigation 8.1 To examine the internal structure of adicotyledonous stem, root and leaf

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rocedure1 Examine the transverse section ofthe dicotyledonous stem using a

hand lens or a stereomicroscope.Make a drawing to show thedistribution of the vascularbundles. Do not drawindividual cells.)Label the following: epidermis,cortex, vascular bundles andpith.

T S of a stem2. Examine the transverse section ofthe stem under the low powermicroscope.

Draw one vascular bundle.Do not draw any cells.)Label the following: phloem,cambium and xylem.

A v scul r bundle
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3. (a) What is the function of the phloem?

b) What are the functions of the xylem?

4. Examine the transverse section of the dicotyledonous root under the low powermicroscope. Make a drawing of the root to show the distribution of the xylem andphloem within the outline diagram shown below. Also draw and label thefollowing: piliferous layer, root hairs and cortex. Do not draw any cells.)

oT S of dicotyledonous root

5. Examine the transverse section of the leaf provided under a low power microscope.Draw the outline of the midrib and part of the lamina. Within this outline, draw thedistribution of the xylem and phloem in the midrib and in one branch vein. Alsodraw and label: the upper and lower epidermis, a stoma with guard cells, cuticle,palisaJe Lissue, spongy mesophyll Do not draw any cells.)

T S of le f


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8. Below is an outline diagram of a leaf hade and label the tissue through whichwater enters the leaf

vein

midrib

T S o le f


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Name: ClassInvestigation B 3 The Ringing experiment

rocedure1 ut off a complete ring of bark from the main stem of a woody twig until the xylemor wood) is exposed twig A shown below). Place the twig in water with the ringimmersed.2. Compare this with another twig that has a ring cut above the water level twig C .3. Set up a control using an unringed twig B.4. Place the apparatus near the window where the twigs received sufficient sunlight.

region withbark removedf---i-+--+- unringed stem

water

Fig. S.l5. Observe the twigs daily. Note where advent itious roots or swellings appear. Make

drawings of your observations.


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uestions1 hat does this experiment tell you about the function of the phloem?

2 Suggest an explanation for your observation


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6 Give n explanation for your observation


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Name: Class:Investigation 8 5 o show transpiration in leaves and stemsTeachers demonstrationj

1 1 ~ ; e J \ . p p a r a t u s and Materials a potted plant a pot of soil 2 bell jars2 polythenebags . .. anhydrous copper sul.fha%

Procedure1. Take a potted plant and wrap a polythene bag round the pot and the stem of theplant.2. Place the pot on a glass plate and cover t with a dry bell jar as shown in Fig. 8.3.3. Set up a control using similar apparatus but without the plant.4. Place the two jars side by side in sunl ight for one hour.

ontrol

bell jar----I

1---'----\-- potted plant

I--+--polythene bag I i~ - - - - - - p o t of soil

glass plate

Fig 8 3

5. What do you observe after 1 hour in(a) the jar with the plant?

(b) the control?


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6. Test any liquid on the inside of the bell jar with anhydrous copper sulphate. Whatdo you observe?

What is the liquid?he liqu id is _

7. What is the reason for covering the pot with the polythene bag?

8. What conclusion can you draw from your observations?


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Name: Class:nvestigation 8 6 o compare transpiration in leaves and stems

Teachers demonstrations~ t u s and Materials

. l. .2 leafytwigs ofabout the sameslze water2beakers oil 2belljars vaselineProcedure

1. Taketwo leafytwigsofabout the same sizefromthe same plant.Cut theend ofeachtwig under water.Thisprevents airfromentering the xylemvesselswhich wouldinterferewith the absorption ofwater by thetwig.

2. Placeeachtwig in abeaker ofwater.Add alittleoilonto the water.3. Cut offalltheleavesfromone twig.Apply vaselineon thecut ends of thepetioles(leafstalks)toprevent water lossthrough the cut ends.4. Apply vaselineonly on thestems ofthe other twig (leafytwig).5. Cover eachbeaker with abelljarasshown in Fig.8.4.Placetheapparatus insunlight.

leaflesstwigwithcutends of petiolevaselined

H_+--_1eafy twigwithstemvaselined

j I I I I I I I - - - t I - - - + - - - o i l - - - + - ~ - - ~

water t -

Fig 8.4

6. What do you observeafterabout 2hours?In jarwith leafytwig:

Injarwith leaflesstwig:


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7 ive n explanation for your observation


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Name: Classnvestigation 8.7 o compare the rate of transpiration through the

upper and lower surfaces of a leaf using cobaltchloride papers

ProcedureThis experiment requires a plant with stomata mainly on the lower surface of the leaves.1. Explain how you can find out whether stomata are found mainly in the lower

epidermis of a leaf.

2. Using a pair of dry forceps place a piece of dry cobalt chloride paper on each of twoglass slides.3. Sandwich an intact leaf (i.e. a leaf still attached to the plant) between the two glassslides as shown in Fig. 8.5. Hold the glass slides in position using two rubber bands.

fI .I. \II

glass slidesrobbe, n ~ a l vi - ,,, kngth t ,lid

Fig 8.5

4. Observe the colour change in the cobalt chloride papers. Which paper turns pinkfaster?


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5 hy are forceps used instead of your fingers to pick up the cobalt chloride papers

6 hat can you conclude from your investigation


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Name: Classnvestigation 8 8 o find out whether transpiration occurs mainlythrough the stomata

t ~ ~ I - p a t a b l s andMaterials~ j < j j > ,~ 0 ; ; i ; . aplantwith stomatafoulldmainly It .tiu'ea{'f )' 0

Oll the lower surface,e.g. broad.. vaseUnedkotyledol\ous leaves l scalpt;l. iY 'aweighfug machineProcedure

1. Cut offthreeleavesofabout thesame sizeand surfacearea.Coat the petioleswithvaselinetoprevent evaporation of water fromthepetioles2. Tieathread totheend of eachpetiolesothat theleafcan be hung up to dry.Note

down the conditionofeachleaf,i.e. turgid or flaccid,withered or not.3. Treatthethreeleavesasfollows:

LeafA Cover the upper surfacewith athin layerofvaseline.LeafB Cover the lower surfacewith vaseline.LeafC Coverboth surfaceswith vaseline.4. Weigheachleafand recordyour resultsin the tablebelow.5. Hang up thethreeleaveswhere they can receivesunlight.

LeafA LeafB LeafCupper surfacecovered lower surfacecovered both surfacecovered

Fig 8.66. Afterafewhours observethe conditionofthe leaves.Recordyour observationsinthetable.7. Weightheleavesagain.Calculatethepercentagemass lossineachleaf.

LeafA LeafB LeafC

Condition of leafat beginning

Condition of leafat end of experiment


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Ieaf Leaf B LeafCOriginal mass (g)

Final mass (g)

Loss in mass (g)

loss in mass

8. Name the process which is mainly responsible for the loss of mass in the leaves.

9. Which leaf has lost the most mass?

Why?

10. Give an explanation for your observations in the other leaves.


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Name: ClassInvestigation 8.9 o measure the rate of transpiration of a potted

plant under laboratory conditionsTeachers demonstration)

Procedure1. Take a well-watered potted plant and wrap a polythene bag tightly round the pot

and the stem of the plant.2. Weigh the plant. Place it near the window in the laboratory.3. After a few hours, e.g. 3 hours, weigh the plant again. Record your result below.(The loss in mass is mainly due to the loss of water vapour during transpiration.)4. Calculate the rate of transpirat ion under laboratory conditions.

Mass of potted plant = gMass of potted plant after 3 hours = gLoss in mass = g

= loss in mass g hRate of transpiration of the plant time takeng h


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Name: Classnvestigation 8 10 o measure the rate of transpiration using a

potometer Teachers demonstrationJ

;;a.leafy o o ~, a filter flasl


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4. Allowafewminutesfortheshoottoreachasteadystatebeforetakinganyreadings.Meanwhileintroducewaterfromthesyringetokeepthemeniscusattheendofthetube.5. Measurethetimetakenforthemeniscustomovethroughagivendistance,e.g.fromB toA Theratemovementofthemeniscusgivestherateofwaterabsorption(orrateoftranspiration).Repeattheexperimentafewtimesandcalculatethemeantimetaken.6. RecordthevolumeofthewatercolumnfromB toA7. Calculatetherateoftranspirationasfollows:

VolumeofwatercolumnfromB to = cm3Meantimetaken = bminutesRateoftranspiration alb cm3perminute

8. Repeattheexperimentunderdifferentenvironmentalconditions.Investigatetheeffectofeachofthefollowingfactors:(a) sunlight(b) wind- useasmallelectricfan(withtheshootstillinsunlight)(c) humidity- enclosetheshootin atransparentplasticbag

9. Recordyourresultsinthetablebelow.Timestakenformeniscus RateoftomovefromB to transpiration(volumeofwaterabsorbed volume (cm3/minute)

betweenB andA cm31st 2nd 3rd Average

reading reading reading timeShootinsunlightShootin windShootinhumidair

10. Whichshoottranspiresthefastest?

Giveyourreasons.

transport of materials in flowering plants

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