11Animals And Plants Transportation In
11Transportation inAnimals and PlantsYou have learnt earlier that allorganisms need food, water andoxygen for survival. They need totransport all these to various parts oftheir body. Further, animals need totransport wastes to parts from wherethey can be removed. Have youwondered how all this is achieved? Lookat Fig. 11.1. Do you see the heart andthe blood vessels? They function totransport substances and together formthe circulatory system. In this chapter,you shall learn about transport ofsubstances in animals and plants.HeartVeinArtery11.1 CIRCULATORY SYSTEMBloodWhat happens when you get a cut onyour body? Blood flows out. But whatis blood? Blood is the fluid whichflows in blood vessels. It transportssubstances like digested food from thesmall intestine to the other parts of thebody. It carries oxygen from the lungsto the cells of the body. It also transportswaste for removal from the body.How does the blood carry varioussubstances? Blood is composed of afluid, called plasma in which differenttypes of cells are suspended.Why is the colour ofblood red ?Fig. 11.1 Circulatory system(Arteries are shown in red colour and veins in blue)2020-21
One type of cells are the red bloodcells (RBC) which contain a red pigmentcalled haemoglobin. Haemoglobinbinds with oxygen and transports it toall the parts of the body and ultimatelyto all the cells. It will be difficult toprovide oxygen efficiently to all the cellsof the body without haemoglobin. Thepresence of haemoglobin makes bloodappear red.The blood also has white blood cells(WBC) which fight against germs thatmay enter our body.Boojho fell down while playing agame and his knee got injured. Bloodwas coming out from the cut. After sometime, he noticed that bleeding hadstopped and a dark red clot had pluggedthe cut. Boojho was puzzled about this.The clot is formed because of thepresence of another type of cells in theblood, called platelets.Blood vesselsThere are different types of blood vesselsin the body. You know that duringinhalation a fresh supply of oxygen fillsthe lungs. Oxygen has to be transportedto the rest of the body.Also, the blood picks up the wastematerials including carbon dioxide fromthe cells. This blood has to go back tothe heart for transport to the lungs forremoval of carbon dioxide as you havelearnt in Chapter 10. So, two types ofblood vessels, arteries and veins arepresent in the body. (Fig. 11.1)Arteries carry oxygen-rich bloodfrom the heart to all parts of the body.Since the blood flow is rapid and at ahigh pressure, the arteries have thickelastic walls.Let us perform an activity to studythe flow of blood through arteries.Activity 11.1Place the middle and index finger ofyour right hand on the inner side of yourleft wrist (Fig. 11.2). Can you feel somethrobbing movements? Why do youthink there is throbbing? Thisthrobbing is called the pulse and it isdue to the blood flowing in the arteries.Count the number of pulse beats in oneminute.How many pulse beats could youcount? The number of beats per minuteis called the pulse rate. A restingperson, usually has a pulse rate between72 and 80 beats per minute. Find otherplaces in your body where you can feelthe pulse.Record your own pulse beats perminute and those of your classmates.Insert the values you obtained in Table11.1 and compare them.122Fig. 11.2 Pulse in the wristSCIENCE2020-21
Table 11.1 Pulse rateS. No.1.2.3.4.5.NamePulse per minuteI am confused! I have learntthat an artery alwayscarries oxygen-rich blood.Paheli explained that thepulmonary artery carries bloodfrom the heart, so it is called anartery and not a vein. It carriescarbon dioxide-rich blood to thelungs. Pulmonary vein carriesoxygen-rich blood from thelungs to the heart.Veins are the vessels which carrycarbon dioxide-rich blood from all partsof the body back to the heart. The veinshave thin walls. There are valves presentin veins which allow blood to flow onlytowards the teryCapillariesFig. 11.3 Schematic diagram of circulationBlood DonationHundreds of people die due tounavailability of blood. Voluntaryblood donation is harmless andpainless and can save precious lives.Blood can be donated at hospitals andother places authorised by thegovernment. Donated blood are storedwith special care in Blood Banks.Refer to Fig. 11.3. Do you see thearteries divide into smaller vessels? Onreaching the tissues, they divide furtherinto extremely thin tubes calledcapillaries. The capillaries join to formveins which empty into the heart.HeartThe heart is an organ which beatscontinuously to act as a pump for thetransport of blood, which carries othersubstances with it.Imagine a pump working foryears without stopping! Absolutelyimpossible. Yet our heart works like apump non-stop. Let us now learn aboutthe heart.The heart is located in the chestcavity with its lower tip slightly tiltedtowards the left (Fig. 11.1). Hold yourfingers inwards on your palm. ThatTRANSPORTATION IN ANIMALS AND PLANTS1232020-21
makes your fist. Your heart is roughlythe size of your fist.What will happen if the blood rich inoxygen and the blood rich in carbondioxide mix with each other? To avoidthis from happening, the heart has fourchambers. The two upper chambers arecalled the atria (singular: atrium) andthe two lower chambers are called theventricles (Fig. 11.4). The partitionbetween the chambers helps to avoidVena CavaAortaPulmonary arteryPulmonary veinLeft atriumRight atriumPartition completelyseparating the twohalvesLeft ventricleRight ventricleFig. 11.4 Sections of human heartPaheli wonders which side ofthe heart will have oxygen-richblood and which side will havecarbon dioxide-rich blood.mixing up of blood rich in oxygen withthe blood rich in carbon dioxide.To understand the functioning of thecirculatory system, start from the rightside of the heart in Fig. 11.3 and followthe arrows. These arrows show thedirection of the blood flow from the heart124SCIENCE2020-21
to the lungs and back to the heart fromwhere it is pumped to the rest of thebody.HeartbeatThe walls of the chambers of the heartare made up of muscles. These musclescontract and relax rhythmically. Thisrhythmic contraction followed by itsrelaxation constitute a heartbeat.Remember that heartbeats continueevery moment of our life. If you placeyour hand on the left side of your chest,you can feel your heartbeat. The doctorfeels your heartbeats with the help ofan instrument called a stethoscope.A doctor uses the stethoscope as adevice to amplify the sound of the heart.It consists of a chest piece that carries asensitive diaphragm, two ear pieces anda tube joining the parts. Doctors canget clues about the condition of yourTubeheart by listening through astethoscope.Let us construct a model of astethoscope with the materials that areavailable around us.Activity 11.2Take a small funnel of 6 –7 cm indiameter. Fix a rubber tube (50 cm long)tightly on the stem of the funnel. Stretcha rubber sheet (or a balloon) on themouth of the funnel and fix it tightlywith a rubber band. Put the open endof the tube on one of your ears. PlaceChest Piece(a) Stethoscope(b) Model ofstethoscopeEar PieceFig. 11.5 Instrument to hear heartbeatTable 11.2 Heartbeat and pulse rateName of studentWhile restingHeartbeatPulse rateTRANSPORTATION IN ANIMALS AND PLANTSAfter running (4 –5 minutes)HeartbeatPulse rate1252020-21
the mouth of the funnel on your chestnear the heart. Now try to listencarefully. Do you hear a regularthumping sound ? The sound is that ofheart beats. How many times did yourheart beat in a minute ? Count againafter running for 4–5 minutes. Compareyour observations.Record your own pulse rate and heartbeat and that of your friends whileresting and after running and record inTable 11.2. Do you find any relationshipbetween your heart beat and pulse rate?Each heart beat generates one pulse inthe arteries and the pulse rate perminute indicates the rate of heart beat.The rhythmic beating of the variouschambers of the heart maintaincirculation of blood and transport ofsubstances to the different parts of thebody.Boojho wonders if sponges andhydra also have blood? Animals suchas sponges and Hydra do not possessany circulatory system. The water inwhich they live brings food and oxygenThe English physician, William Harvey(A.D.1578 –1657), discovered thecirculation of blood. The currentopinion in those days was that bloodoscillates in the vessels of the body.For his views, Harvey was ridiculedand was called “circulator”. He lostmost of his patients. However, beforehe died, Harvey’s idea aboutcirculation was generally accepted asa biological fact.as it enters their bodies. The watercarries away waste materials and carbondioxide as it moves out. Thus, theseanimals do not need a circulatory fluidlike the blood.Let us now learn about the removalof waste other than carbon dioxide.11.2 EXCRETIONINANIMALSRecall how carbon dioxide is removedas waste from the body through thelungs during exhalation. Also recall thatthe undigested food is removed duringegestion. Let us now find out how theother waste materials are removed fromthe body. You may wonder where theseunwanted materials come from!When our cells perform theirfunctions, certain waste products arereleased. These are toxic and hence needto be removed from the body. Theprocess of removal of wastes producedin the cells of the living organisms iscalled excretion. The parts involved inexcretion form the excretory system.Excretory system in humansThe waste which is present in the bloodhas to be removed from the body. Howcan this be done? A mechanism to filterthe blood is required. This is done bythe blood capillaries in the kidneys.When the blood reaches the two kidneys,it contains both useful and harmfulsubstances. The useful substances areabsorbed back into the blood. Thewastes dissolved in water are removedas urine. From the kidneys, the urinegoes into the urinary bladder through126SCIENCE2020-21
contains water and salts. Boojho hasseen that sometimes in summer, whitepatches are formed on our clothes,especially in areas like underarms.These marks are left by salts present inthe sweat.Does sweat serve any other function?We know that the water kept in anearthen pot (matka) is cooler. This isbecause the water evaporates from thepores of the pot, which causes cooling.KidneyUreterPaheli wants to knowwhether other animals alsourinate?Urinary bladderUrethraUrinary openingFig. 11.6 Human excretory systemtube-like ureters. It is stored in thebladder and is passed out through theurinary opening at the end of amuscular tube called urethra (Fig. 11.6).The kindeys, ureters, bladder andurethra form the excretory system.An adult human being normallypasses about 1–1.8 L of urine in 24hours. The urine consists of 95% water,2.5% urea and 2.5% other wasteproducts.We have all experienced that we sweaton a hot summer day. The sweatThe way in which waste chemicalsare removed from the body of theanimal depends on the availabilityof water. Aquatic animals like fishes,excrete cell waste as ammonia whichdirectly dissolves in water. Someland animals like birds, lizards,snakes excrete a semi-solid, whitecoloured compound (uric acid). Themajor excretory product in humansis urea.Sometimes a person’s kidneys maystop working due to infection orinjury. As a result of kidney failure,waste products start accumulating inthe blood. Such persons cannotsurvive unless their blood is filteredperiodically through an artificialkidney. This process is called dialysis.TRANSPORTATION IN ANIMALS AND PLANTS1272020-21
Similarly, when we sweat, it helps to coolour body.11.3 TRANSPORTPLANTSOFSUBSTANCESINIn Chapter 1 you learnt that plants takewater and mineral nutrients from the soilthrough the roots and transport it to theleaves. The leaves prepare food for theplant, using water and carbon dioxideduring photosynthesis. You also learnt inChapter 10 that food is the source ofenergy and every cell of an organism getsenergy by the breakdown of glucose. Thecells use this energy to carry out vitalactivities of life. Therefore food must bemade available to every cell of anorganism. Have you ever wondered howwater and nutrients absorbed by theroot are transported to the leaves? Howis the food prepared by the leaves carriedto the parts which cannot make food?The root hair increase the surface areaof the root for the absorption of waterand mineral nutrients dissolved inwater. The root hair is in contact withthe water present between the soilparticles [Fig. 11.7 (a)].Can you guess how water movesfrom the root to the leaves? What kindof transport system is present in plants?Boojho thinks that plantsmay have pipes to transportwater to the entire plant likewe have in our homes for thesupply of water.Transport of water andmineralsPlants absorb water and minerals bythe roots. The roots have root hair.Root hair(b)(a)Xylem vesselsFig. 11.7 Transport of water and minerals in(a) a section of root, (b) a tree128SCIENCE2020-21
Well, Boojho is right. Plants havepipe-like vessels to transport water andnutrients from the soil. The vessels aremade of special cells, forming thevascular tissue. A tissue is a group ofcells that perform specialised functionin an organism. The vascular tissue forthe transport of water and nutrients in theplant is called the xylem [Fig. 11.7 (a)].The xylem forms a continuousnetwork of channels that connects rootsto the leaves through the stem andbranches and thus transports water tothe entire plant [Fig. 11.7 (b)].Fig. 11.8 (a) Stem placed in coloured water(b)(c)Fig. 11.8 (b) Water moves up in the stem(c) Enlarged view of open end of stemPaheli says her mother putsladyfinger and other vegetables inwater if they are somewhat dry.She wants to know how waterenters into them.You know that leaves synthesisefood. The food has to be transported toall parts of the plant. This is done bythe vascular tissue called the phloem.Thus, xylem and phloem transportsubstances in plants.Activity 11.3We would require a glass tumbler, water,red ink, a tender herb (e.g., Balsam),and a blade for this activity.Pour water to fill one-third of thetumbler. Add a few drops of red ink tothe water. Cut the base of the stem ofthe herb and place it in the glass as shownin Fig. 11.8(a). Observe it the next day.Does any part of the herb appearred? If yes, how do you think the colourreached there?You can cut the stem across and lookfor the red colour inside the stem (Fig.11.8(b) and 11.8(c)).From this activity we see that watermoves up the stem. In other words, stemconducts water. Just like the red ink,minerals dissolved in water also moveup the stem, along with water. Waterand minerals go to leaves and otherplant parts, through narrow tubes(xylem) inside the stem (Fig. 11.7(b)).TRANSPORTATION IN ANIMALS AND PLANTSBoojho wants to know whyplants absorb a large quantityof water from the soil, then giveit off by transpiration!1292020-21
TranspirationIn Class VI you learnt that plantsrelease a lot of water by the process oftranspiration.Plants absorb mineral nutrients andwater from the soil. Not all the waterabsorbed is utilised by the plant. The waterevaporates through the stomata presenton the surface of the leaves by the processof transpiration. The evaporation of waterfrom leaves generates a suction pull (thesame that you produce when you suckwater through a straw) which canpull water to great heights in thetall trees. Transpiration also coolsthe plant.KeywordsAmmoniaArteryBloodBlood vesselsCapillaryCirculatory systemDialysisExcretionExcretory systemHaemoglobinHeart beatKidneysPhloemPlasmaPlateletsPulseRed blood cellRoot hairStethoscopeSweatTissueUreaUreterUrethraUric acidUrinary bladderVeinWhite blood cellXylemWhat you have learntnIn most animals the blood that circulates in the body distributes foodand oxygen to different cells of the body. It also carries waste productsfrom different parts of the body for excretion.nCirculatory system consists of the heart and blood vessels.nIn humans, blood flows through arteries and veins and the heart actsas a pumping organ.nBlood consists of plasma, RBC, WBC and platelets. Blood is red due tothe presence of a red pigment, haemoglobin.nThe human heart beats about 70–80 times per minute in an adultperson. This is called heart rate.nArteries carry blood from the heart to all parts of the body.nVeins carry blood from all parts of the body back to the heart.nRemoval of waste products from the body is called excretion.130SCIENCE2020-21
nExcretory system of humans consists of two kidneys, two ureters, aurinary bladder, and urethra.nSalts and urea are removed along with water as sweat.nFish excrete waste substances such as ammonia which directly dissolvein water.nBirds, insects and lizard excrete uric acid in semi-solid form.nWater and mineral nutrients are absorbed by roots from the soil.nNutrients are transported along with water to the entire plant via thevascular tissue called xylem.nThe vascular tissue for the transport of food to the various parts of theplant is phloem.nA lot of water is lost by plants in the form of vapour through stomataduring transpiration.nTranspiration generates a force which pulls up water absorbed by theroots from the soil, to reach the stem and leaves.Exercises1. Match structures given in Column I with functions given in Column II.Column I(i)Column IIStomata(a)Absorption of water(ii)Xylem(b)Transpiration(iii)Root hairs(c)Transport of food(iv)Phloem(d)Transport of water(e)Synthesis of carbohydrates2. Fill in the blanks.(i)The blood from the heart is transported to all parts of the body bythe.(ii)Haemoglobin is present incells.(iii)Arteries and veins are joined by a network of(iv)The rhythmic expansion and contraction of the heart is called.(v)The main excretory product in human beings is(vi)Sweat contains water and(vii)Kidneys eliminate the waste materials in the liquid form called.(viii) Water reaches great heights in the trees because of suction pullcaused by.TRANSPORTATION IN ANIMALS AND PLANTS1312020-21
3. Choose the correct option:(a)In plants, water is transported through(i)(iii)(b)xylem(ii)phloemstomata(iv)root hairWater absorption through roots can be increased by keeping theplants(i)in the shade(ii)in dim light(iii)under the fan(iv)covered with a polythene bag4. Why is transport of materials necessary in a plant or in an animal?Explain.5. What will happen if there are no platelets in the blood?6. What are stomata? Give two functions of stomata.7. Does transpiration serve any useful function in the plants? Explain.8. What are the components of blood?9. Why is blood needed by all the parts of a body?10. What makes the blood look red?11. Describe the function of the heart.12. Why is it necessary to excrete waste products?13. Draw a diagram of the human excretory system and label the variousparts.Extended Learning — Activities and Projects1. Find out about blood groups and their importance.2. When a person suffers from chest pain, the doctor immediately takesan ECG. Visit a doctor and get information about ECG. You may evenlook up an encyclopaedia or the internet.Did you know?There is no substitute for blood. If people lose blood from surgery or injuryor if their bodies cannot produce enough blood, there is only one way toget it — through transfusion of blood donated by volunteers. Blood isusually in short supply. Donating blood does not decrease the strength ofthe donors.132SCIENCE2020-21
Count the number of pulse beats in one minute. How many pulse beats could you count? The number of beats per minute is called the pulse rate. A resting person, usually has a pulse rate between 72 and 80 beats per minute. Find other places in your body where you can feel the pulse. Record your own pulse beats per minute and those of your classmates.
Plants Pupils should be taught to: and recording the weather and its effect on plants (plants growing and leavesidentify and name a variety of common plants, including garden plants, wild plants and trees, and those classified as deciduous and evergreen [1] describe the basic structure of a variety of common plants including roots,
plants including deciduous and evergreen trees. Seasonal changes - trees in winter. Year 2: Living things and their habitats - identify and name a variety of plants. Plants - find out why plants need water to grow. Year 3: Plants - identify the functions of different parts of flowering plants and explore the requirements of plants for life.
plants Seedless vascular plants Gymnosperms Angiosperms Reproduction by spores Hardened vascular tissue Seeds Flowers Notice in Table 28-1 that vascular plants can be further divided into two groups, seedless plants and seed plants. Seedless plants include the phylum of ferns and three phyla made up of plants closely associated with ferns.
seedless vascular plants. 8. Plants with seeds are further divided into the two groups of gymnosperms and angiosperms. 28.2 Non-Vascular Plants Bryophytes 9. Give three examples of nonvascular plants: – Moss – Liverworts – Hornworts 28.3 Vascular Plants Tracheophytes 10.Classify each of the following as
Flowering Plants Tracheophytes Cone- bearing Plants Moss Plants Bryophytes Fern Plants Seed Plants Liverworts Plants are generally classified according to the absence or presence of plant parts such as the flowers, seeds, fruits, leaves, or stem. They are grouped according
Transportation Engineering The transportation engineering faculty offer graduate course in transportation planning, design, operations and safety with an emphasis on surface transportation. The faculty are engaged in research in transportation planning and safety, intelligent transportation systems, transportation systems analysis, traffic flow .
3/1/2011 6 Diverged prior to the origin of seeds Seedless vascular plants Lycophytes, pteridophytes and seed-producing plants are vascular plants or 21 producing plants are vascular plants or tracheophytes Possess tracheids for water and mineral conduction and structural support
Last previous edition approved in 2018 as A234/A234M – 18. DOI: 10.1520/A0234_A0234M-18A. 2 For ASME Boiler and Pressure Vessel Code applications see related Specifi-cation SA-234 in Section II of that Code. 3 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards volume information, refer .
