TRANSPORTATION AND EXCRETION - Badhan …badhaneducation.in/assignment/class 10th/science/CLASS... · Web view9. Explain briefly the blood transfusion chart. 10. Write the main difference

TRANSPORTATION AND EXCRETION .

TRANSPORTATION AND EXCRETION

INTRODUCTIONLiving organism require oxygen, water and food in every ell of its various tissues to sustain life.

Transport of different materials and gases are essential both in plants and animals. In animals, the transport of digest food, oxygen, hormones, excretory products to relevant organs and tissues is brought about by a well-defined organ system called the circulatory system comprising of blood, heart and blood tissues. Similarly, in higher plants transport of nutrients, oxygen for respiration and food materials is brought about by a well defined vascular system comprising of the conducting tissues, xylem and phloem.

All plants and animals produce substance due to a number of metabolic activities occurring in their body tissues. These substance are to be eliminated from the body as they are toxic in nature. In plants, photosynthetic and respiratory wastes are excreated through stomata of leaves and lenticels of stems. The main excretory products from animal body such as carbon dioxide, water are given out through lungs, skin etc. and the nitrogenous waste products are excreted out by different excretory organs such as nephridia, malpighian tubules, kidneys, etc in different animals.

ANIMALS TERMS AND CONCEPTS1. Transportation. It is a life process in which a substance absorbed or synthesized in one part is moved to

other parts of the body.2. Transportation in plants.

(i) Transport of water and minerals. In plants, the transport of water and minerals from the roots upwards to all other parts takes place through xylem tubes.(ii) Transport of food and other substances. Phloem transports synthesized food from the leaves to the rest of the plant body.

3. Conducting tissue. It is a tissue comprising of xylem and phloem that carries substances from one part of the plant body to another. Within the vascular bundle, the xylem is internally located while phloem lies towards the outside of the organ.

4. Xylem. It is a tissue that transports water and dissolved mineral nutrients from the roots to all other parts of the vascular plant.(i) Tracheids. They are elongated, thin spindle-shaped dead cells with pits in their thick cell walls. In a transverse section a tracheid appears polygonal or rectangular having a large lumen.(ii) Vessels. It is a tube within the xylem composed of joined vessel elements. Vessels are cylindrical in shape with their ends open and are placed one above the other so as to form a continuous column stretching from roots to leaves.

5. Phloem. It is a tissue that conducts food materials in vascular plants from regions where they are produced, i.e., leaves to regions such as growing points, where they are needed for the purpose of storage or consumption. Phloem consist of sieve tube, which is a series of cells within the phloem tissues. They are connected to form a cylindrical tube that conveys soluble material in plant stems. Sieve tubes placed one above the other forming continuous column with the ends covered with sieve plate.

6. Transpiration. It is defined as “the process by which plants lose water in the vapour form into the surrounding air”.Transpiration occurs mainly from the leaves through pores (stomata) whose primary function is gas exchange.It helps in the upwards movement of sap or water from roots to leaves.

7. Types of transpiration. There are mainly four types of transpiration:(i) Cuticular transpiration. Losses of water through the cuticles, which lie outside the epidermal layer of leaves, stem flowers etc.

Graphics By:- Roshan Dhawan 1 Written By:- P. K. Badhan

Fig. 10.1: XylemA. Tracheids B. Vessels that transport water and mineral

salts.


(ii) Stomatal transpiration. It is the most important type of transpiration in which loss of water is through stomata.(iii) Lenticular transpiration. Lenticels are the pores in the stems of the plant through which loss of water takes place.(iv) Bark transpiration. It is the loss of water through the bark of the tree.

Fig. 10.2: Phloem tubes that conduct prepared food.8. Importance of transpiration:

(i) Ascent of sap. It is the upward movement of cell sap, i.e., water and minerals through the xylem. Because of transpiration from the leaves, cell sap is concentrated and the increases the osmotic pressure which draws from the cells of lower level.(ii) Removal of excess of water. Transpiration helps to remove excess water.

(iii) Cooling effect. Transpiration helps to regulate the temperature of the plant since evaporation reduces temperature.(iv) Absorption and distribution of salts. The continuous water current produced by transpiration helps to absorb and distribute the salts.

9. Translocation. It is defined as “the process of transport of food from leaves to other parts of the plant body through phloem”. It is necessary as every part of the plant needs food for harnessing energy and for building and maintaining the organism.

10. Transportation in human beings. In human’s transportation of oxygen, nutrients, hormones and other substances to the tissue, CO2 to the lungs and waste products to the kidneys is carried out by a well-defined circulatory system.

11. Circulatory system. It comprises of the heart, blood vessels, blood, lymphatic vessels and lymph, which together serve to transport materials throughout the body.

12. Blood. It is bright red-colored liquid connective tissue that circulates in the entire body by the muscular pumping organ, the heart. The volume of blood is about 6 liters in an adult human body.


PhloemParenchyma

Sieve plates

Sieve tubes

Companion cell


13. Composition of blood.

BLOOD

Plasma Blood cells

Serum Fibrin Erythrocytes Leucocytes Platelets& clotting (red blood corpuscles) (White Bloodfactors Corpuscles)

Granulocytes Agranulocytes

Neutrophils Eosinophils Basophils Lymphocytes Monocytes

14. Plasma. It is the liquid part of the blood excluding blood cells.(i) Plasma consists of water, in which many substances are dissolved including plasma proteins (albumin, globulin, fibrinogen and antibodies), slats (sodium and potassium chlorides and bicarbonates), food substances (amino acids, glucose, fats), hormones, digested and waste excretory products.(ii) In the plasma, floats the RBC, WBC and blood platelets.(iii) The straw colour of plasma is due to the presence of small amounts of pigments such as bilirubin, i.e., a bile pigment.(iv) Plasma without fibrinogen is called serum.

Plasma = Serum + Fibrinogen15. Blood Corpuscles.(i) Red blood corpuscles (RBC) or Erythrocytes. These are minute, circular biconcave discs having no

nucleus. They look red due to the presence of red colored pigment, haimoglobin, which acts as carrier of oxygen from lungs to tissue and carbon dioxide from tissues to lungs. The life span of RBC is 12 days.

(ii) White blood corpuscles (WBC). These are large, nucleated colored cells and are numerous than erythrocytes.WBC are mainly of two types-Granulocytes and Agranulocytes.

A. Granulocytes. They have a granular cytoplasm and lobed nucleus. They are mainly of three types:(a) Newtrophils. They have fine granules in their cytoplasm and are stained with neutral days. Nucleus is multilobed.(b) Eosinophils. They have granules of cytoplasm stained with acid dyes like eosin and nucleus mainly has two lobes.(c) Basophils. They have granules of cytoplasm stained with basic dyes like methylene blue and the nucleus is large and indistinctly lobed.

B. Agranlocytes. Their cytoplasm does not contain granules but a single large nucleus is present.


PlasmaRBC (No Nucleus)

WBC Lobed Nucleus

PlateletsFig. 10.4 Human Blood


They are two types.(a) Lymphocytes. They have a large spherical nucleus occupying most of the cytoplasm.(b) Monocytes. They are the largest of the white blood corpuscles and have a large kidney or horse shoe shaped nucleus.

(iii) Blood platelets. These are small fragments of blood cells derived from the cells called megakaryocytic, which are giant cells in the red bone narrow. Platelets are rounded, colorless, biconvex and non-nucleated blood cells; which help in the coagulation of blood. They are called thrombocytes.

16. Functions of blood. Blood performs the following functions:(i) Transport of oxygen. Red blood corpuscles contain haemoglobin that combines with oxygen to form oxyhaemoglobin which is transported to the tissues of the body for the purpose of respiration.(ii) Transport of carbon dioxide. Carbon dioxide produced by the tissues as a result of respiration by the blood plasma and also by the haemoglobin to the lungs from where it is removed.(iii) Transport of nutrients. The digested and absorbed nutrients like glucose, amino acids, fatty acids, vitamins, etc. are first transported to the liver and then to the whole of tissues for their storage, oxidation and synthesis to new substances.(iv) Transport of excretory products. Nitrogenous wastes like ammonia, urea and uric acid of body are transported to the kidneys from where they are eliminated by the blood.(v) Regulation of body temperature. The blood flows in all parts of the body, so it equalizes the body temperature. It carries heat produced from one place to another place of the body.(vi) Maintenance of pH. The plasma proteins act as buffer system and maintain required pH of the bdy tissues.(vii) Transport of hormones. The plasma of blood transports various hormones from one region to another and bring about the co-ordination in the working of the body.(viii) Water balance. The blood maintains water balance to constant level by distributing uniformly over the body.(ix) Protection from diseases. The WBC (eosinophils, neutrophils, monocytes) engulf the bacteria and other disease causing organisms by phagocytosis. The lymphocytes produce antibodies against the invading antigens.(x) Clotting of blood. Blood forms a clot at the site of injury, thus preventing the further loss of blood. Blood helps in rapid healing of wounds.

17. Immunity. It is the ability of an animal or plant to resists infection by disease producing organisms.18. Blood clotting. It is the mechanism that prevents the loss of blood at the site of an injury or wound by

forming a ‘blood clot’. It is essential to prevent excessive bleeding and this is a complex process.The major events in blood clotting or coagulation are given in this flow chart:



19. Fibrin. It is the insoluble protein that forms at the side of an injury and it is also the foundation of a blood clot.

20. Fibrinogen. It is the soluble protein in the blood plasma which gets transformed into fibrin when blood is shed.

21. Serum. It is supernatant yellow fluid which comes out after the blood clot dries up. Serum is plasma without its fibrinogen.

22. Antigen. It is any substance, a bacteria or virus that the body regards as foreign and it may be formed in or introduced into the body. It is capable of causing some disease in the body and is present in the red blood cells of the donor.

23. Antibody. It is a specialized plasma protein produced by certain white blood cells (lymphocytes) in response to entry into the body of a foreign substance antigen in order to render it harmless.

24. Blood groups. Individual’s blood may be classified into different groups, based on the presence or absence of certain antigenic proteins, i.e. Agglutinates on the surface of the red blood cells.(i) In humans, the two most important blood group systems are the ABO system and the system involving the Rhesus factor.(ii) Land Steiner discovered four blood groups in human beings based on the mutual compatibility of the antigens and antibodies. They are A, B, AB and O.(iii) A person having O blood group can give blood to all the groups and hence called universal donor. Similarly, a person with AB blood group is called universal recipient as he can receive blood of all other groups.

25. Blood transfusion. The transfer of blood from a healthy person to another person is known as blood transfusion.(i) Transfusion is generally given in case of serious blood loss due to some injury or surgical operation.(ii) A person who donates the blood is called the donor and the person who receives the blood is called the recipient.(iii) In human blood cells, two different antigens were discovered and named A and B. Their corresponding antibodies in the plasma were termed ‘a’ and ‘b’.Blood Group Antigen present Antibody present Can donate to Can receive from

in RGB in PlasmaA A b A and AB A, OB B a B and AB B, OAB A and B None AB A, B, AB, OO None a and b A, B, AB, O O

Table : Blood transfusion Chart26. Rh factor. It is kind of antigen in the blood which first found in the Rhesus monkey. On the basis of

presence or absence of Rh factor human beings can be divided as – Rh positive (Rh +) and Rh negative (Rh–)


TRANSPORTATION AND EXCRETION .27. Blood vessel. Each blood vessel is a tubular structure through which the blood of an animal flows. There

are three types of blood vessels of different sizes involved in blood circulation, viz, arteries veins and capillaries, which are all connected to form a continuous closed system.(i) Arteries are wide and thick walled vessels that carry oxygenated blood from the heart to different organs of the body. Aorta is the main artery. Arteries branch out into arterioles and finally into capillaries.(ii) Veins are thin-walked, having values that carry deoxygenated blood from different organs to the heart. The blood in veins flows under less pressure than in arteries.(iii) Capillaries are extremely narrow and thin walled blood vessels. These walls are permeable, so that water and dissolved substances pass in and out, exchanging oxygen, carbon dioxide, dissolved nutrients and excretory products with the tissues.

28. The human heart. The heart is pumping organ that receives blood from the veins and pumps it into the arteries.It is a muscular organ that plays the role of a pump in the circulatory system.The heart in man is situated in thoracic cavity which lies above the diaphragm between the two lungs.

Fig. 10.8 External Structure of Human HeartIt is enclosed in a double walled membranous sac, the pericardium.The heart is made of special muscle cells called cardiac muscle fibers.


TRANSPORTATION AND EXCRETION .A. Chambers of the heart. The interior of the heart is divided into four chambers which receive the

circulatory blood.(i) The Atria (auricles). The two superior chambers are called the right and left atria. The atrias are separated by a partition called the inter-atrial septum. The sinuatrial ode (SAN) or the pacemaker is located in the upper wall of the right atrium.(ii) The Ventricles. The two interior chambers of the heart are the right and left ventricles. They are separated from each other by an inter-ventricular septum. The atria and ventricles are separated by connective tissue that also form the valves.

B. Valves of the heart. Valves are muscular flaps which prevent the blood to flow back through it.Two types of heart valves are distinguish:(i) The atrio ventricular valves. These valves separate the atria from the ventricles. The right side of the heart possesses the tricuspid valve or right atrio ventricular valve and the left side of the heart possesses the bicuspid valve or mitral.(ii) Semilunar valves. These are located in the arteries leaving the heart. The pulmonary semi-lunar valves lies in the opening where the pulmonary trunk leaves the right ventricle and aortic semi-lunar valve lies at the opening between the left ventricle and aorta.

C. Blood flow through the heart.(i) The right atrium receives deoxygenated blood from all parts of the parts through large veins called vena cava.(ii) When the right atrium is full of blood and it contracts, the tricuspid valves open under pressure and the blood is forced into the right ventricle.(iii) When the right ventricle is full of blood, it contracts and the blood is pumped into the pulmonary trunk.(iv) The pulmonary trunk divides into the right and left pulmonary artery, each into the left auricle.(v) The oxygenated blood returns to the heart via the pulmonary veins that empty into the left auricle.(vi) When the left auricle contracts the blood passes into the left ventricle by the opening of the bicuspid valve.(vii) On contraction of the left ventricle, the blood is pumped into largest artery called aorta.(viii) The aorta branches into vessels which transport blood to the heart and all body parts.

Fig. 10.9: Internal Structure of Human Heart29. Double circulation in Man. The circulatory system of man is called double circulation as the blood

passes through the heart twice in one complete cycle of the body. It involves tow circulations:(i) Pulmonary circulation. This circulation is maintained by the right side of the heart.It begins in the right ventricle which expels the blood into the pulmonary trunk.The blood flowing into the vascular system of the lungs, becomes oxygenated and returns to the heart (left atrium) through pulmonary veins.(ii) Systemic circulation. This circulation is maintained by the left ventricle which sends the blood into the aorta.



The aorta divides into arteries, arterioles and finally to capillaries and thereby supplies oxygenated blood to various parts of the body.From there deoxygenated blood is collected by venues which join to form veins and finally vena cava and pour blood into the heart.

Fig. 10.10: Double Circulation in Man30. Blood pressure. It is pressure exerted by the flow of blood through the aorta and its arteries.

(i) The blood pressure varies according to the contraction or systolic phase (Lubb sound) and relaxation or diastolic phase (dup sound).(ii) The normal blood pressure is said to be 120/80 mm of mercury, but is also varies from person to person depending on age, sex, heredity, physical and emotional state and other factors.(iii) The blood pressure is measured

31. Heart beat. A heart beat is one complete contraction and relaxation of the heart. Each beat consists of the simultaneous contraction of the two auricles followed by the simultaneous contraction of the two ventricles.

32. Pace maker. The Sinoatrial (SA) Node is a small mass of specialized muscle cells in the mammalian heart, found in the wall of the right atrium near the opening of the vena cava. This tissue initiates and maintains the heart beat. Sometimes, when it fails to function normally, an electronic device called the “pace maker” is implanted surgically into the chest of such heart patients to produce and maintain the heart beat. This device is used when the heart’s own pace maker is defective of diseased.

33. Electrocardiograph. The electrocardiogram (ECG) is called a graphical representation of the electrical changes during the heart beat.The instrument for recording ECG is called electrocardiograph.The recordings are made from electrodes fastened over the heart and also on both arms and legs.When analysed, the ECG gives vital information about the rate and rhythm of the heart and condition of the muscles.The changes in the normal pattern of an ECG may indicate heart irregularities or diseases.

34. Lymphatic system. It is a system of tiny called lymph vessels or lymphatics and lymph nodes or lymph glands in the human body which transports the liquid, lymph from the body tissues to the blood circulatory system.Lymphatic system runs parallel to veins and consists of the following parts:Lymph is a light yellow fluid containing lymphocyte cells which fight against infection. Lymph flows only in one direction, from tissues to heart. Lymph is also called extracellular fluid as its lies outside the



cells, Lymph is derived from blood plasma containing water with dissolved proteins, inorganic salts, food materials, waste product and WBCs.Lymphatic capillaries are thin walled capillaries forming a network in every organ except nervous system. They start from minute knob-like blind ends. Lymph drains into lymphatic capillaries which join to form large lymph vessels.Lymphatic vessels form a second pathway for fluid returning from the tissues to the heart. The lymphatic capillaries unite to form lymphatic vessels which are very small veins in structure.Lymph nodes or lymph glands are situated in the course of the lymph vessels and generally occur in groups and are oval or kidney shaped. They are rich with phagocytes and lymphocytes, thus act as filters for the microorganisms.

Fig. 10.12: Human Lymphatic System35. Functions of lymph or lymphatic system.

(i) It takes part in the nutritive process of the body.

(ii) It protects the body by killing the germs drained out of the body tissues with the help of lymphocytes contained in the lymph nodes.

(iii) It helps removing the waste products like fragments of dead cells, etc.

36. The first sound “Lubb” is produced when the auriculo-verticular valves get closed at the start of ventricular systole.

37. The second sound “Dup” is produced when the semilunar valves of aorta and pulmonary artery gets closed.

38. Excretion. It is the process of elimination of metabolic waste products from the body of an organism. The organs that are involved in this process constitutes the excretory system.

39. Excretion in Animals. The organs of excretion vary greatly in different groups of animals.

(i) Amoeba - Wastes and excess water by simple diffusion through contractile vacuole.

(ii) Sponges - Waste material diffuses out through the osculum.

(iii) Cnidaria (Hydra) - Wastes are removed through the oral opening.

(iv) Flatworm - Flame cells

(v) Earthworm - Nephridia

(vi) Crustaceans (Prawns) - Green glands

(vii) Insects - Malpighian tubules



(viii) Mammals - Kidneys (main excretory organ)

Liver, skin and lungs are accessory excretory organs.

40. Excretion in Amoeba.

The removal of nitrogenous waste products and water in Amoeba is carried out by simple diffusion through contractile vacuole.

Waste produced in the cell and surplus water enter into contractile vacuole from the cytoplasm, as a result the vacuole increase in size and moves close to the plasma membrane.

On contact with the plasma membrane contractile vacuole bursts and releases the contents outside the body.

Fig. 10.12: Excretion in Amoeba

41. Excretion in Earth worm

Nephridia are the excretory organs of earthworm, which are attached to the septa or internal walls which are attached to the septa or internal walls present in the body of the earthworm. They are the septal nephridia.

Nephridia are also present int the skin of the earth worm called integumentary nephridia.

The fluid from body cavity of earthworm carrying waste enter the nephridium through neptrostome.

The useful substances present in the fluid are reabsorbed by cells lining the nephridial tubule and are passed into blood.

The remaining fluid with wastes moves out of nephridiopore.

Septal nephridia drain with wastes into the intestine from where it is thrown out of the body along with undigested waste.

Integumentary nephridia have their nephridiopores in the skin and pour out waste directly outside the body.



Fig. 10.13: Excretory organ of Earthworm-Naphridium

42. Nephridium. It is an assembly of long tubules lined with cilia. One end of nephridium has a funnel like structure called nephrostome and the other end of nephridium has an opening called nephridiopore.

43. Excretion in humans. The excretory system of human beings collects and drains out the wastes from the body. It consists of two kidneys, tow ureters, a urinary bladder and an urethra.

Fig. 10.14: Human Excretory system

(i) Kidneys. It is mean excretory organ.

Each kidney is bean shaped reddish brown in color and are located in the abdomen, one on either side of the vertebral column.

The left kidney is placed a little higher than the right kidney.

The renal artery brings in the dirty blood containing waste substance into the kidneys.

The renal vein carries away the cleansed blood from the kidneys.



Fig. 10.15: Structure of a kidney

(ii) Ureters or excretory tubes. They are the thin muscular tubes coming out from each kidney which opens into the urinary bladder. Ureters are ducts which drain out urine from the kidneys.

(iii) Urinary bladder. It is muscular tube that arises from the neck of the bladder and conducts the urine to the outside through opening at its end the urinary opening.

44. Structure of Nephron. Each kidney is made up of a large number of excretory units called nephrons.

A nephron consists of a long coiled tubule differentiated into proximal tubule, loop of henle and distal tubule. The latter opens into the collecting tubule.

At the proximal end of the nephron lies a double walled cup shaped structure called Bowman’s capsule.

The Bowman’s capsule and the tubule together makes a nepron.

One end of the tubule is connected to the Bowman’s capsule and its other end to a urine collecting duct of a kidney.

The Bowman’s capsule contains a bundle of blood capillaries which is called glomerulus.

One end of the glomerulus is attached to renel artery and the other end to the renel vein.

In the glomerulus, blood comes in through afferent arteriole and blood is drained out through efferent arteriole.

The function glomerulus is to filter the blood passing through it.

The function of tubule of nephron is to allow the selective reabsorption of the useful substances into the blood capillaries.



Fig. 10.16: Structure of a Nephron

45. Functions of kidney.

(i) It removes the poisonous substances such as urea, other waste salts and excess water from the blood and excrete them in the form of a yellowish liquid called urine.

(ii) It regulates the osmotic pressure/water balance of the blood.

(iii) It regulates pH of the blood.

1 MARK QUESTIONS

1. Pulmonary artery is different from pulmonary vein in having

(a) Large lumen (b) Thick muscular walls

(c) No endothelium (d) Valves

2. Hemoglobin is a type of

(a) Carbohydrate (b) Skin pigment

(c) Vitamin (d) Respiratory pigment

3. Which of the four chambers of the human heart has the ticket muscular walls?

4. Write the full form of SA-node. What is its other name?

5. Name the structures which help in excretion in

(i) tapeworm and (ii) earthworm

6. What is formed when CO2 combines with globins of reduced hemoglobin? Where does it occur?

7. Why is blood group identification not required while transfusing serum?


TRANSPORTATION AND EXCRETION .8. The basic functional unit of kidney is

(a) Henle’s loop (b) Nephron

(c) Nephridium (d) Pyramid

9. Name the excretory organs of the following animals:

(i) Sponges (ii) Hydra (iii) Tapeworm (iv) Earthworm

(v) Cockroach (vi) Prawn (vii) Frog

10. Name the central element present in hemoglobin.

11. Name excretory organs of Prawn.

2 MARKS QUESTIONS

1. Name the passage in sequence through which urine passes from kidney to the outside in humans. How is urine prevented from flowing back into the ureters?

2. Why is sino-atrial node also called pace maker?

OR

3. What is a pace maker?

4. What is a cardiac cycle?

5. What is the full form of SA node? Where is it located? Why is it called a pacemaker?

6. Draw a simple diagram of the internal structure of human heart showing the veins entering it. Also label the veins and the chambers.

7. What is lymph? Mention its function in our body.

8. Where are the sounds of ‘LUBB’ and ‘DUP’ produced in heart during cardiac cycle?

9. What is the average life span of an erythrocyte in human? Where are they produced in foetus and in adult human respectively?

10. The heart rates of an elephant, a human and a mouse are nearly, 25, 72, and more that 200 per minute respectively.

(i) What conclusion can you draw from these observations?

(ii) what is the significance of these differences in the heart rate?

3 MARKS QUESTIONS


TRANSPORTATION AND EXCRETION .1. Why is transportation of materials necessary?

2. What is the need of special tissues or organs for transport of substances in plants and animals?

3. Describe transport of the following materials in plants (i) water (ii) mineral and (iii) food

4. Draw and label the parts of the human excretory system.

5. What is osmoregulation? How does it take place in humans?

6. Give the difference between pulmonary circulation and systemic circulation.

7. How will you say that there is double circulation of blood in human body?

8. What is ECG? Write its mechanism.

9. Explain briefly the blood transfusion chart.

10. Write the main difference between xylem and phloem.

11. Differentiate between lymphatic capillaries and blood capillaries.

12. Draw a neat labeled diagram of the kidneys and the associated structures of the urinary system of man.

13. Write an explanatory note on ‘dialyses.

14. Draw a sieve tube and label the various parts. Name the dead elements of the phloem.

15. What are the different types of transpiration? Explain each one in brief.

16. What is the difference between RBC and WBC?

17. What is hemoglobin? State its functions.

18. What is normal heart rate? How the rate is counted? From normal resting condition following exercise, does the rate change? If so state the reason for such change.

19. What is nephridia? Describe the structure and function of excretory organ in earthworm.

20. Describe the blood circulation in human heart.

21. Write about the composition of blood in a chart form.

22. Describe in brief the types of valves present in heart.

23. What is Rh factor? What is its significance?

24. Describe various types of leucocytes.

25. Write a note on the importance of transpiration.

26. Give an account on the different types of blood vessels.


TRANSPORTATION AND EXCRETION .27. Describe the structure of the main excretory organ in man.

28. Give the function of kidney.

29. Show the flow of blood with the help of diagrammatic representation of the human heart.

SELF EVALUATION TEST

Time allowed: 1 Hour Max. Marks: 25

1. Which organ acts a pump in the circulatory system?

2. What type of substance controls the absorption of water or removal of excessive water from the body?

3. Which part of the body is responsible for excretion in (i) Amoeba, (ii) Earth worm?

4. Name the blood vessel which (a) brings oxygenated blood to the kidney and (b) takes away deoxygenated blood from it.

5. What are the major differences between artery and vein?

6. Mention two ways in which blood protects the body against infection.

7. What is a heat beat? How fast does the hear usually beat?

8. Write a note on lymphatic system in human beings stating two major functions of lymph.

9. What is the role of skin, lungs and liver in the process of excretion in human beings?

10. Define transpiration. Mention its role in movement of water and minerals.

11. With the helps of an illustration, describe the various parts of human heart




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TRANSPORTATION AND EXCRETION - Badhan …badhaneducation.in/assignment/class 10th/science/CLASS... · Web view9. Explain briefly the blood transfusion chart. 10. Write the main difference