CBSE Class 10 Biology Life Processes Worksheet Set D

MCQ Questions for NCERT Class 10 Science Life Processes

Question. The opening and closing of stomatal pore is regulated by       
(a) O2 concentration
(b) CO2 concentration
(c) temperature
(d) turgidity of guard cells

Answer : D

Question. Iodine solution is used to test the presence of           
(a) proteins
(b) fats
(c) starch
(d) enzymes

Answer : C

Question. Nitrogen, an essential element used in the synthesis of proteins, is obtained by plants in the form of         
(a) atmospheric nitrogen
(b) nitrates and nitrites
(c) amino acids
(d) peptides

Answer : B

Question. Which part of alimentary canal receives bile?           
(a) Oesophagus
(b) Pharynx
(c) Large intestine
(d) Small intestine

Answer : D

Question. Absence of salivary amylase in the saliva will not affect         
(a) breakdown of protein in mouth
(b) breakdown of fat in mouth
(c) breakdown of starch in mouth
(d) assimilation of vitamins in mouth

Answer : A

Question. The process of photosynthesis requires           
(a) chlorophylls and light only
(b) chlorophylls and CO2 only
(c) chlorophylls, CO2 and H2O only
(d) chlorophylls, CO2, H2O and light

Answer : D

Fill in the blanks.

Question. ...... is the muscular partition between the chest cavity and the abdominal cavity.
Answer : Diaphragm

Question. ...... serves as a storehouse of food where partial digestion takes place.
Answer : Stomach

Question. ...... are respiratory organs found in aquatic animals.
Answer : Gills

Question. When air passes through the nose, it is warmed, moistened and ...... .
Answer : filtered

Question. The opening leading to the larynx is called ...... .
Answer : glottis

Question. From the larynx air goes to ...... .
Answer : trachea

Question. Each bronchus divides and branches out in the form of thinner tubes called ...... .
Answer : bronchioles

True (T) or False (F).

Question. The energy released during cellular respiration is not used immediately to synthesize ATP.
Answer : false

Question. Carnivores like tigers have a shorter small intestine because meat is easier to digest.
Answer : true 

Question. Small intestine receives the secretions of liver and pancreas.
Answer : true 

Question. The alimentary canal and the glands associated with digestion constitute the human digestive system.
Answer : true 

Important Questions for NCERT Class 10 Science Life Processes

Match the columns 

(i) Glycolysis                (a) Fermentation
(ii) Human muscles      (b) 3-carbon compound
(iii) Mitochondria          (c) Gills
(iv) Yeast                     (d) Epiglottis
(v) Pyruvate                (e) Cytoplasm
(vi) Fish                       (f) Lactic acid
(vii) Larynx                  (g) Lungs
(viii) Trachea               (h) Balloon-like structures
(ix) Mammals              (i) Cartilage rings
(x) Alveoli                    (j) ATP synthesis

Answer : (i) (e) (ii) (f) (iii) (j) (iv) (a)  (v) (b) (vi) (c) (vii) (d) (viii) (i) (ix) (g) (x) (h)

Very-Short-Answer Questions

Question. Where does peristaltic movement occur?
Answer : Oesophagus

Question. From where is bile secreted?
Answer : Liver

Question. What are saprophytes?
Answer : They obtain food from dead organisms.

Question. Give two examples of saprophytes.
Answer : Bread moulds, yeasts

Question. Where are villi located?
Answer : On the wall of the ileum in the small intestine

Question. Where is pharynx located?
Answer : Pharynx is located just behind the nose.

Quetion. What are the methods used by plants to get rid of excretory products?
Answer : To get rid of excretory products, plants use the following ways:
(1) The plants produce carbon dioxide as a waste product during respiration and oxygen as a waste product during photosynthesis. The plants get rid of gaseous waste products through stomata in their leaves and lenticels in stems.
(2) Many waste products are stored in vacuoles of the cells. Plant cells have comparatively large vacuoles. Some waste products are stored in the leaves. They are removed as
the leaves fall off.
(3) Some waste products such as resins and gums are stored, especially in non- functional old xylem.
(4) Some waste products such as tannins, resins, gums are stored in bark, thereby removed as barks are peeled off. (-) Plants excrete some waste products through roots into the soil around them. (-) Plants also get rid of excess water through transpiration.

Quetion. If human urine is allowed to stand for sometime, it smells of ammonia, why?
Answer : Urea present in urine gets decomposed into ammonia by the action of bacteria. So it smells strongly of ammonia

Quetion. Name the two ways in which glucose is oxidized to provide energy in various organisms.
Answer : The two ways in which glucose is oxidized to provide energy in various organisms are Aerobic respiration and Anaerobic respiration. into a new complete organism.

Quetion. Why do fishes die when taken out of water?
Answer : Fishes respire with the help of gills. Gills are richly supplied with blood capillaries and can readily absorb oxygen dissolved in water. Since fishes cannot absorb gaseous oxygen, they die soon after they are taken out of water.

Quetion. Answer the following:
(A) mention the adaptations of leaf for photosynthesis.
(B) Why does absorption of digested food occur mainly in small intestine?
Answer : (A) The adaptations of leaf for photosynthesis are as follows:
(1) Leaves have chlorophyll i.e. the main site for photosynthesis.
(2) The shape of the leaves enables to absorb maximum sunlight for photosynthesis.
(3) Leaves have stomata which help in gaseous exchange and transpiration. Stomata help the leaves in taking in carbon dioxide and raw material for photosynthesis.
(4) The wide network in leaves helps in transport of water to the leaves and prepared food to the entire plant from the leaves.
(B) Maximum absorption of digested food occurs in small intestine due to following reasons
(1) Digestion process gets completed in small intestine.
(2) Inner lining of small intestine is provided with has millions of tiny, finger like projections called Villi. Each Villus has a network of fine blood capillaries close to the surface. The presence of Villi  gives the inner walls of small intestine greater surface area which helps in rapid absorption of food.
(3) Wall of intestine is richly supplied with blood vessels through which the absorbed food is taken to each and every cell of the body.

Quetion. How do carbohydrates, proteins and fats get digested in human beings?
Answer : Digestion of carbohydrates: The human saliva contains an enzyme called slivery amylase which digests starch (carbohydrate) present in food into maltose sugar. Thus, the digestion of carbohydrate begins in the mouth itself. When the slightly digested food reaches the small intestine, pancreatic amylase present in the pancreatic juice breaks down the starch into maltose. The walls of the small intestine secrete the intestinal juice (maltose) which finally converts it into glucose and completes the digestion of carbohydrates. Digestion of proteins: The digestion of proteins begins in the stomach. In the stomach, gastric glands secrete gastric juice which contains an enzyme called pepsin which converts the proteins into peptones. Pancreatic juice contains trypsin which digests the proteins into peptides and the intestinal juice completes the process of digestion of proteins, thus converting it into amino acids. Digestion of fats: The digestion of fats begins in the stomach. In the stomach, gastric glands secrete a small amount of gastric lipase that breaks down the fats present in the food. In the small intestine, the pancreatic lipase breaks down the emulsified fats. The intestinal juice, secreted by the walls of small intestine, finally converts the fats into fatty acids and glycerol.

Quetion. (A) Write the function of the following in the human alimentary canal:
(i) Saliva
(ii) HCl in stomach
(iii) Bile juice
(iv) Villi
(B) Write one function each of the following enzymes:
(i) Pepsin
(ii) Lipase 
Answer : (A) Function of given substances in
(i) Saliva:
(1) Saliva moistens the food so it can be swallowed easily.
(2) Saliva contains the enzyme salivary amylase that breaks some starches into sugar.
(ii) HCl in stomach:
(1) The hydrochloric acid creates an acidic medium which facilitates the action of the enzyme pepsin.
(2) It also kills germs or pathogens.
(iii) Bile juice:
(1) It makes the acidic food coming from the stomach alkaline, so as to enable the action of pancreatic enzymes.
(2) It contains bile pigments and bile salts which carry out emulsification of fats.
(iv) Villi:
(1) These are finger-like projections present in the inner lining of the small intestines which increase the surface area for absorption.
(2) In the large intestine villi absorb water from the unabsorbed food.
(B) Function of enzymes is given below:
(i) Pepsin: It is found in gastric juice and digests proteins found in ingested food.
(ii) Lipase: It digests the emulsified fats and converts it to fatty acids and glycerol.

Quetion. What would happen if platelets were absent in the blood?
Answer : The blood has platelet cells which circulate around the body and help to clot the blood at the time of inury. In the absence of platelets, the process of clotting will be affected. Platelets play the important role of coagulation of blood. No blood coagulation would take place in the absence of platelets. This would be a dangerous situation in case of an inury, at it would result in excessive blood loss and can even prove lethal for the person.

Class 10 Science Life Process Notes and Questions

Question: Where do plants get each of the raw materials required for photosynthesis?
Answer : (a) Carbon dioxide from atmosphere.
(b) Light from Sun
(c) Water from Soil
(d) Chlorophyll from chloroplast of green plants.

Question: Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?
Answer : The separation of the right and left side of heart is useful to prevent oxygenated blood and deoxygenated blood from mixing. Such separation allows a highly efficient supply of oxygen to the body. This is useful in animals that have high energy needs, such as birds and mammals that constantly use the energy to maintain their body temperature.

Question: What are the methods used by plants to get rid of excretory products?
Answer : (i) Plant produces carbon dioxide as wastes during respiration and oxygen as waste during photosynthesis.
(ii) Excess of water is removed through transpiration.
(iii) Some waste products like gums and resins are stored in older xylem tissue.

Question: How is amount of urine produced regulated?
Answer : The amount of urine depends on how much excess of water is in the body and how much a water soluble waste is to be excreted. If the amount of water and dissolved wastes in boy are more than amount of urine will be more and if amount of wastes is less the amount of urine produced will be less.

Question: With the help of diagram, show pulmonary circulation in man.
Answer : Diagram – Pulmonary circulation in man.

Question: Discuss the major steps involved in process of nutrition in human beings.
Answer : Major steps involved in human nutrition are –
a) Ingestion – Intake of food through mouth. Humans have holozoic mode of nutrition. They engulf solid particles.
b) Digestion – The break down complex food material into simpler one in alimentary canal with the help of mechanical as well as chemical process.
c) Absorption – Digested food is absorbed by the small finger like projections, villi present in the small intestine.
d) Assimilation – Absorbed food reaches to all cells via blood, and utilized for energy, growth and development.
e) Excretion – Undigested food from small intestine passed into large intestine, and then it is thrown out by Anus.

Question: Give an experiment to prove the essentiality of light for photosynthesis
Answer : a) Destarched the plant by leaving it in dart for 48 – 72 hours.
b) Now place strips of black paper or metal foil over destarched leaves and expose them to light for several hours.

Question: Why and how does water enter continuously into the root xylem of plants?
Answer : Xylem transports water and minerals to the plant body. The roots of a plant have hair called root hairs. The root hairs are directly in contact with the flam of water in between the soil particles. Water and minerals get into the root hair by the process of diffusion. The water and minerals absorbed by the root hair form the soil pass from cell to cell by osmosis through the epidermis root cortex, endodermis and reaches the root xylem. The xylem vessels of the root the plant are connected to the xylem vessels into stem. Therefore, the water containing dissolved minerals enter the root xylem vessels into stem xylem vessels. The xylem vessels of the stem branch into the leaves of the plants. So the water & minerals carried by the xylem vessels in the stem reach the leaves through the branched xylem vessels which enter from the petiole into the each part of the leaf. Thus the water and minerals form the soil reach through the root and stem to the leaves of the plants. Evaporation of water molecules from the cells of a leaf creates a suction which pulls water form the xylem cells of roots. The loss of water in the form of vapour from the aerial parts of the plants is known as transpiration.

Question: What are outside raw materials used for by an organism?
Answer : Outside raw materials used for by an organism includes:
a. Food
b. Water
c. Oxygen

Question: What are the functions of human respiratory system?
Answer : (i) Gaseous exchange for the cellular respiratory process.
(ii) Sound production by vocal cords
(iii)Abdominal compression which helps in urination, passing of faces and childbirth.
(iv) Laughing and sneezing for self-cleaning the respiratory surface.

Question: What processes would you consider essential for maintaining life?
Answer : The processes essential for maintaining life are
a. Nutrition
b. Respiration
c. Transportation
d. Excretion

Question: How respiration does takes place in plants?
Answer : There are three modes for the exchange of gases in plants –
a) Some small plants can carry out gaseous exchange by simple diffusion over their whole surfaces.
b) Large fowering plants exchange gases through stomata on their leaves and green stem.
c) In woody stems, exchange occurs through cracks in the bark or lenticels.

Question: Explain the structure of chloroplast.
Answer : Fig – structure of chloroplast.

Question: What are difference between autotrophic and heterotrophic nutrition?
Answer : Distinction between autotrophic and heterotrophic nutrition:

Question: What is the role of the acids in our stomach?
Answer : HCl plays following role in our stomach:
(a) Make the medium acidic for action of enzyme pepsin.
(b) Kills the harmful bacteria present in food
(c) Prevents fermentation of food

Question: What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?
Answer : The rate of breathing is slower in terrestrial organisms as compared to aquatic organisms. This is due to the fact that in water, the amount of oxygen is less as compared to air while in aquatic organisms the rate of breathing is faster.

Question: How is food transported in plants?
Answer : Food is transported in plants through phloem which consists of sieve tubes, sieve cells and companion cells. The food prepared in leaves in soluble form transported to leaves phloem. Active transport of food passes to all other parts of plants.

Question: What are different ways in which glucose is oxidized to provide energy in various organisms?
Answer : The pathways of break-down of glucose in various organisms are as below:

Question: What is the role of following in human digestive system –
a) mucous
b) Bicarbonate
c) Trypsin
Answer : a) Mucus – It protects the inner living of stomach from HCl.
b) Bricarbonate – It makes the acidic food alkaline so that pancreatic enzymes act on it.
c) Trypsin – It digest proteins into amino acids.

Question: How is oxygen and carbon dioxide transported in human beings?
Answer : In human beings, a pigment hemoglobin is present in RBC which has high affinity for oxygen, takes up the oxygen from the air in the lungs and carry it to tissues which are deficient in oxygen. Some oxygen is carried in dissolved state in blood plasma. Carbon dioxide is more soluble in water than oxygen is mostly transported in the dissolved form in our blood.

Question. In human alimentary canal, name the site of complete digestion of various components of food. Explain the process of digestion.
Answer : In small intestine, complete digestion of various components of food take place. The process of digestion of food in mouth, stomach and small intestine in human body are as follows:
Mouth: Digestion of food begins in the mouth. Saliva present in mouth contains a digestive enzyme, called salivary amylase, maltose and dextrins, which breaks down starch into sugar. Stomach: Stomach stores and mixes the food received from the oesophagus with gastric juices. The main components of gastric juice are hydrochloric acid, mucus and pepsinogen. Hydrochloric acid dissolves bits of food and creates an acidic medium. In this medium, pepsinogen is converted to pepsin which is a protein-digesting enzyme. Mucus protects the inner lining of the stomach from the action of HC1.
Small Intestine: Small intestine is the site of complete digestion of carbohydrates, proteins and fats. Small intestine produces intestinal juice from the glands present in its wall. The intestinal juice helps in further digestion of food. Small intestine also obtains digestive juices from liver and pancreas. The liver produces bile juice that causes emulsification of fats and the pancreas produces pancreatic juice for digesting proteins and emulsified fats. This digested food is finally absorbed through the intestinal walls.

Question. List the three kinds of blood vessels of human circulatory system and write ¦ their functions in tabular form.
Answer : Three types of blood vessels in human circulatory system are: Arteries, Veins and Capillaries.
Their functions are tabulated below:

Question. (a) “The breathing cycle is rhythmic whereas exchange of gases is a continuous process”. Justify this statement.
(b) What happens if conducting tubes of circulatory system develops a leak? State in brief, how could this be avoided?
(c) How opening and closing of stomata takes place?
Answer : (a) The breathing cycle involves inhalation and exhalation of air due to alternate expansion and contraction of thoracic cavity. Thus it is a rhythmic process. But exchange of gases is a continuous process as it takes place between the blood and each and every cell, by diffusion.
(b) The circulatory system will become inefficient if it develops a leak. This could be avoided by maintaining a normal blood pressure.
(c) When water flows into the guard cells, the guard cells swell and the stomatal pore opens up. When water moves out the guard cells shrinks and the stomatal pore closes.

Question. Describe in brief the function of kidneys, ureters, urinary bladder and urethra.
Answer : The Kidneys filter the blood and concentrate the filtrate to make urine. They also help regulate blood pressure.
Ureters transport the urine to the urinary bladder.
Urinary bladder is like a holding tank for the urine until it’s ready to be excreted. Urethra is the tube that connects the urinary bladder to the outside of the body for excretion.

Question. Explain the process of breakdown of glucose in a cell (ii) in the absence of oxygen.
Answer : The process of breakdown of glucose in a cell are as follows:

The first step in the breakdown of glucose both in presence of 02 and in absence of O2 is same. In this step, glucose is broken down into pyruvate.
Second step which involves further breakdown of private into simple compounds can take place in two different ways:
(a) In presence of O2: In the presence of 02, private is converted into C02 and water. Energy released during aerobic respiration is much greater than that released during an anaerobic respiration.
(b) In absence of O2: In the absence of 02 in yeast, pyruvate is converted into ethanol and C02 and the process is called fermentation. In absence of 02, in our muscle cells, pyruvate is converted into lactic acid. The build up of lactic acid in muscle cells causes cramps

Question. Draw a diagram of the front view of human heart and label any six parts including at least two, that are concerned with arterial blood supply to the heart muscles.
Answer :

Long Answer Type Questions

Question. (a)Explain how does the exchange of gases occur in plants across the surface of stems, roots and leaves.
(b) How are water and minerals transported in plants ?
Answer : (a) In plants there are tiny pores called stomata on leaves and lenticels in stem which facilitate the exchange of gases. Carbon dioxide is taken in and oxygen given out {during photosynthesis} and vice versa during respiration.
(b) Water and minerals are transported within the plant by the Xylem vessels (mainly in an upward direction); these are part of the vascular system which also includes Phloem vessels. Phloem transports the products of photosynthesis within the plant, to all parts like the stem, roots, fruits etc. in all directions.

Question. Draw a diagram of human excretory system and label renal artery and urethra.
State in brief the function of :
1. renal artery
2. kidney
3. ureter
4. urinary bladder
Answer :

Renal artery: The renal artery carries blood to the kidneys from the abdominal aorta. This blood comes directly from the heart and is sent to the-kidneys to be filtered before it passes through the rest of the body. Up to one-third of the total cardiac output per heartbeat is sent to the renal arteries to be filtered by the kidneys. Each kidney has one renal artery that supplies it with blood.
The filtered blood then can exit the renal vein.
Kidney: The kidneys perform the essential function of removing waste products from the blood and regulating the water fluid levels. The kidneys regulate the body’s fluid volume, mineral composition and acidity by excreting and reabsorbing water and inorganic electrolytes.
Ureter: The ureter is a tube that carries urine from the kidney to the urinary bladder.’ There are two ureters, one attached to each kidney.
Urinary bladder: The urinary bladder is an expandable muscular sac that stores urine before it is excreted out of the body through the urethra.

Question. (a) Draw a diagram to show the nutrition in Amoeba and label the parts used for this purpose. Mention any other purpose served by this part other than nutrition.
(b) Name the glands associated with digestion of starch in human digestive tract and mention their role.
(c) How is required pH maintained in the stomach and small intestine?
Answer : (a) 

Pseudopodia serves the purpose of locomotion apart from nutrition.
(b) The salivary gland is associated with digestion of starch in human digestive tract.
It secretes saliva which contains enzyme salivary amylase. This enzyme converts starch into maltose (sugar).
(c) Gastric glands present on the walls of the stomach release HC1. HC1 creates an acidic medium, which facilitates the action of enzyme pepsin. Bile juice from liver makes the food alkaline in small intestine for the pancreatic enzymes to act.

Question. (a) Leaves of a healthy potted plant were coated with vaseline to block the stomata. Will this plant remain healthy for long? State three reasons for your Answer :
(b) State any two differences between autotrophic nutrition and heterotrophic nutrition.
Answer : (a) No, this plant will not remain healthy for long. The plant will begin to die because
(i) Gaseous exchange will not take place.
(ii) No absorption of C0₂, hence no photosynthesis.
(iii) Transpiration will not occur; hence no transportation of water.

Question. (a) List the three events that occur during the process of photosynthesis.
Explain the role of stomata in this process.
(b) Describe an experiment to show that “sunlight is essential for photosynthesis.”
Answer : (a) The three events that occur during the process of photosynthesis are:
(i) Absorption of light energy by the green pigment chlorophyll.
(ii) Conversion of light energy into chemical energy and the splitting of water molecule into hydrogen and oxygen.
(iii) Reduction of carbon dioxide into carbohydrate. Role of Stomata Stomata are tiny pores present on the surface of leaves. They are also present on the surface of young stems. Stomata are mainly engaged in the exchange of gases (entry of CO₂ and release of O₂ ) associated with photosynthesis. Plant closes the stomata when it does not need CO₂ for photosynthesis.
(b) Sunlight is essential for photosynthesis

Procedure:
(i) Place a healthy green potted plant in a dark room for 1-2 days. This is done to ensure that the plant consumes all its reserve food and the leaves do not contain any starch.
(ii) Then, cover a portion of a leaf of this plant on both sides with two uniform pieces of black paper, fixed in position with two paper clips.
(iii) Now, expose this plant to bright light. After a few hours, remove the leaf and decolorize it with alcohol and test the presence of food (starch) with iodine solution.
Observation: It can be observed that the portion of the leaf covered with black paper does not (food),
Conclusion: This is because the food prepared by plants through the process of photosynthesis is stored as starch. Starch reacts with the iodine solution to give blue-black colour. Only those portions of the leaf that were exposed to sunlight could photosynthesise. Hence, gives blue- black colour when tested with iodine. The portion of the leaf covered with black paper did not receive sunlight. Hence, starch was not produced. Thus, it can be concluded that the sunlight is essential for photosynthesis.

Question. (a) Draw a diagram to show open stomatal pore and label on it:
(i) guard cells
(ii) chloroplast
(b) State two functions of stomata.
(c) How do guard cells regulate the opening and closing of stomatal pore?
Answer : (a)

(b) Two functions of stomata are:
(i) Exchange of gases between the plant and the atmosphere takes place through stomata.
(ii)Transpiration in plants takes place through stomata.
(c) Opening and Closing of Stomatal Pore: The opening and closing of the pore is a function of the guard cells. The guard cells swell when water flows into them causing the stomatal pore to open. Similarly, the pore closes if the guard cells shrink. As large amount of water is lost through these stomata, the plant closes these pores when it does not require carbon dioxide for photosynthesis.

Question. (a) Draw a diagram of excretory system in human beings and label the following parts. Aorta, kidney, urinary bladder and urethra.
(b) How is urine produced and eliminated ?
Answer : (a) Refer Figure in Q. 63
(b) Blood from the heart comes into the kidneys afferent and efferent arteriols from the renal arteries where it enters about 2-3 million nephrons per kidney. Then, it goes through the glomerulus a tugt or bunch of blood capillaries and get rid of some of the unwanted substances like urea, uric acid, creatinine in the blood and then continues through the renal tubules. The loop of Henley, reabsorb certain substances such as water (actually if body is dehydrated, body will send anti-diuretic hormone (ADH) to kidneys to prevent extra water from going into urine and thus saving water for body and get rid of anything else that isn’t wanted, then the urine goes through ureters to bladder and then to urethra where it is excreted out of body as urine.

Question. (a) Draw the structure of a nephron and label the following on it: Glomerulus, Bowman’s capsule, Renal artery, Collecting duct.
(b) What happens to glucose that enters the nephron along with filtrate?
Answer : (a)
(b) During excretion in human beings, glucose which enters the nephron along with filtrate gets reabsorbed by blood capillaries surrounding the nephron.

Q1 How exchange of gases take place in plants?

Q2 Differentiate between photosynthesis and respiration.

Q3 Explain the mechanism of breathing in human beings.

Q4 How does water rise in tall trees?

Q5 Leaves of a potted plant are coated with Vaseline to block the stomata. Will this plant remain healthy for long? State the 3 reasons for your answer.

Q6 How is prepared food transported to different parts of the plant?

Q7 What is blood? What are the components of blood? Also write the function of each component.

Q8 What are the advantages of having very thin and highly branched capillaries for blood flow?

Q9 What is the difference between the blood flowing in the arteries and that flowing in the veins?

Q10 What is the meaning of the term “Double circulation”?

Q11 What will happen if excess bleeding takes place and what natural device preventing it?

Q12 Correct the false statement

  a) The walls of the atrium are thicker than the ventricles

  b) The oxygen carrying blood goes into the left auricle

  c) Valves open on both the sides.

  d) Xylem transports food material.

  e) The blood circulation in man is of open type in man

Q13 Differentiate between excretion ands osmoregulation? Describe how excretion takes place in amoeba.

Q14 What is dialysis? How is it useful?

Q15 What is excretion? How is solid and gaseous waste excreted in humans?

Q16 List the functions of blood.