By | April 23, 2017



Q.1 What are life processes? Name the main life processes?

Ans.1 Processes that maintain life are called life processes like nutrition, respiration, excretion, transportation etc.

Q.2 What criteria do we use to judge whether the living being is dead or alive?

Ans.2 It can be the movement of body or movement of body party or breathing.

Q.3 Differentiate between living and non living beings?


Living Non Living
1. Show locomotion or movement of body parts. 1. Don’t move on their own.
2.Show all major life processes. 2. Don’t show any life processes.
3. Show growth processes. 3. Don’t show growth processes.
4. They reproduce. 4. They don’t reproduce.
5. They are made up of cells. Eg:- plants, animals, human etc. 5. They are not made up of cells.

Eg:- Stones, mud etc.


Q.4 What are outside raw materials used by organisms?

Ans.4 Outside raw materials are used for:-

  1. Food for obtaining energy.
  2. Oxygen for respiration.
  3. Water to maintain 75% balance in the body.
  4. Green plants use CO2 , sunlight as raw material for preparing their food during photosynthesis.


Q.5 Why is diffusion insufficient to meet the oxygen requirements of multi cellular organisms?

Ans.5 In unicellular organisms no specific organ required for taking in food , exchange of gases and removal of waste from the body as the whole surface of organism is in direct contact with the environment. So, diffusion can bring out all the processes. But in multicellular organisms, diffusion is not sufficient to bring out all these processes in all the cells as it only work for small diseases.

Q.6 What is nutrition?

Ans.6 The consumption of food by living organisms is called nutrition.


Q.7 What are the different types of nutrition and differentiate between them?

Ans.7 Types of nutrition are heterotrophic and autotrophic.

Autotrophic Nutrition Heterotrophic Nutrition
1. Nutrition in which organisms make their own food with the help of raw material in the nature by the process of photosynthesis is called autotrophic nutrition. 1. Nutrition in which organisms are directly or indirectly dependent on the autotrophs for food is called heterotrophic nutrition.
2. All green plants show autotrophic nutrition and are called autotrophs. 2. All herbivores and carnivores are dependent on green plants directly or indirectly. Hence they are known as heterotrophs.


Q.8 What are different types of heterotrophic nutrition?

Ans.8 Different types of heterotrophic nutrition are parasitic nutrition, holozoic and saprophytic nutrition.

  • Saprophytic: Organisms that show saprophytic nutrition are called saprophytes like fungi, bacteria etc . These organisms obtain their food from the dead and decaying organic matter.
  • Parasitic: Organisms that show parasitic nutrition are parasites. They live on or in the other living organisms which are called hosts and derive the nutrition from them. So, some of them are called endoparasites (inside the host cell) and ectoparasites(outside the host cell). Parasites always harm the host. Eg:- Lice, Roundworms, Ticks etc.
  • Holozoic: They are the organisms in which organism take in whole food which undergoes digestion and then it is absorbed by the body. Eg:- Amoeba, and all higher animals including human beings show holozoic nutrition.

Ques .9 Give example of parasitic plants?


  • Cuscuta (Dodder plant)
  • Striga

Ques.10 What are the different stage of holozoic nutrition?

Ans. Different stage of holozoic nutrition are :-

  1. Ingestion
  2. Digestion
  3. Absorption
  4. Egestion
  5. Assimilation

Ques.11 Name the process by which plants make their own food. What are the raw materials used for it?

Ans. Green Plants make their  own food by the process of photosynthesis.  The raw material used for it are carbon dioxide gas, water, chlorophyll and light.

Ques.12 write the  reaction of photosynthesis?


6Co+ 12 H2O –—sunlightchlorophyll—–> C6H12O6 +6H2O +6O2

Ques.13  State the event that take place during photosynthesis.

Ans. 13

  • Absorption of light energy by chlorophyll
  • Conversion of light energy into chemical energy and splitting up of water molecules into hydrogen and oxygen with the release of oxygen.
  • Reduction of carbon dioxide by hydrogen to from carbohydrates


Ques.14   Draw a well labelled diagram of cross-section of a leaf show internal parts.



Ques. 15 Name the cell organelle where photosynthesis take place?

Ans. 15 Photosynthesis takes place in chloroplast.

Ques.16  Name the pigment that take past in photosynthesis.

Ans.16  Chlorophyll( green pigment)


Ques.17 Draw a well labelled diagram of open and closed stomata.




Ques.18  What are stomata? Explain their functions & structures.

Ans. 18 They are tiny pores that are on the epidermis of the leaf. Each stomata has a pair of guard cells which surrounds their pore. These guard cells have nuclear, cytoplasm, chloroplast etc. Their shape in dicots is kidney or bean shaped in monocots a helps in exchange of gases and evaporation of water during transpiration.


Ques.19 How do stomata open and close?

Ans.19 Each stomata has guard cell which control the opening and closing of stomata pore. When water enters the guard cell lose water, it shrink and he pore closes.


Ques.20 How will test for absence or presence of starch in a leaf.

Ans.20 Take a polled plant with variegated leaves keep it in a dark room for three days so that all starch is used up. Then keep it in sunlight foe 6 hours. Then take a leaf from the plant and mark the green areas of the leaf on a sheet of paper. Then dip the leaf in boiling water to make it soft. Then dip it in alcohol and heat in  water bath to decolourise it and remove the chlorophyll then wash the leaf in water and dip it in dilute iodine solution . it will be seen that only the green parts of the leaf turns blue black. This shows that chlorophyll in necessary for photosynthesis.

 Ques. 21 With the help of an activity show that Co2 is necessary for photosynthesis?


  • Take 2 potted plants of some size.
  • Keep them in a dark room for three days.
  • Now place each plant on separate glass- plate place a watch glass containing potassium hydroxide by the side of one of the plants. The potassium hydroxide is used to absorb co2.
  • Cover both plants will separate bell-jars
  • Use Vaseline to seal the bottom of the jars to the glass plats so that the set up is all tight.
  • Keep the plants in sunlight for about 2 hrs
  • Pluck a leaf from each plant and check for the presences of starch as in above activity.
  • We observe that there is no co2 is first as KOH absorbs the air. Starch is not formed in the first jar.
  • This shows that co2 is necessary for photosynthesis.


Ques.22 where do plants yet each of the raw material required for photosynthesis?

Ans. For photosynthesis plants yet co2 from air around them and water from the soil. The co2 enter the leaves through stomata while water is absorbed by the roots from the soil and is sent to the leaves through the stem. Plants get light from the sun and the chlorophyll in present in the cells of the leaves.

Ques.23 what are the production and by-products of photosynthesis?

Ans. The products of photosynthesis is glucose and the by products is oxygen gas.

Ques.24  How does amoeba obtain its nutrition ?

Ans.24  diagram

Amoeba takes in food using temporary flings like extensions of cell surface which fuse over the food particles forming a food vacuole. Inside the food vacuole, complex substances are broken down into simple are which then diffuse into cytoplasm. The remaining undigested material is moved to the surface of the cell and thrown out.

Ques.25 Draw a well-labelled diagram of human digestive system or elementary canal.

Ans.25   Diagram


Ques.26 Name the  organs of digestive system in series.


  • Mouth
  • Pharynx
  • Oesophagus
  • Stomach
  • Small intestine
  • Large intestine
  • Anus



Ques.27  Name the glands of human digestive system.


  • Salivary glands
  • Liver
  • Pancreas

Ques.28  What is the function of Saliva?

Ans.  Saliva helps to moisten the food while chewing , Saliva has an enzyme called salivary amylase which breaks down starch into maltose sugar, it a;so helps to convert the food into a soft round ball called bolus for easy swallowing to the food pipe or oesophagus.

Ques. 29 what is the function of stomach?

Ans. The stomach is a muscular bag which store the food for 2 and 21/2  hours.

It has a gastric juice which consists of HCL and enzyme pepsin. Pepsin reaks down proteins to peptones, after this the food is sent to the small intestine.


Ques. 30 State the function of hydrochloric acid  in stomach?

Ans. The HCL in the stomach creates an acidic medium for the proper action of  the enzyme pepsin, it also kill the bacteria that come along with the food.

Ques.31 What is the function of mucus in the stomach?

Ans.31  The mucus in the stomach   protects the inner lining of the stomach from the action of hydrochloric acid under normal conditions.

Ques. 32  What happens to the food in the duodenum?

Ans. In the duodenum the food is mixed with bile juice from the liver which helps in emulsification of the fats. The food also gets mixed with the pancreatic juice which has many enzymes that breaks down proteins and fats. These enzymes are trypsin that break down proteins and lipase that break down fats.


Ques.33 What happens to the food in small intestine ?

Ans.  When the food reaches small intestine the digestion of starch ,protein and fats is completed with the help of the various enzymes that are present in the intestinal juice. The digestion is complete ones here with the conversion of all that carbohydrates into glucose, all the protein into amino acids and all the fats into fatty acids and glycerol.

Ques. 34 How  is the food absorbed in small intestine ?

Ans. The food is absorbed in the small intestine through lungs- like projections called villi which present inside small intestine.

Ques.35 what is the function of digestive enzymes?

Ans.  Their function is :-

  • To break down the large molecules of food into their individual components like starch into glucose , protein into amino acids and fats into fatty acids and glycerol.

Ques.36  Name the enzymes that break down starch, protein and fats?

Ans. Starch- Salivary amylase

Proteins- Pepsin , Trypsin

Fats- lipase

Ques.37 Explain the process of digestion in human beings?

Ans. In the mouth : the food is broken into smaller particles by the teeth and mixed with saliva from the salivary glands saliva contains the enzyme salivary amylase which converts starch into maltose sugar, the tongue helps to taste the food and roll it is the mouth to convert it into a bolus. Then the food passes through the oesophagus into the stomach.

In the stomach: the gastric juice which contains the enzyme pepsin, HCL & mucous. Pepsin break down proteins , HCl makes the medium acidic and help in the action of pepsin mucous. Protects the walls of the stomach from the action of the acid. Then the food passes into small intestine.

In the upper parts of small intestine called duodenum: the food is mixed with bile from liver and pancreatic juice from the pancreas. Bile breaks down fats into smaller globules this is called emulsification of fats. Pancreatic juice contains the enzymes trepsin and lipase. Trypsin break down proteins and lipase breaks down fats.

In the small intestine: The gland in the walls of the small intestine produces intestinal juice. The enzyme of the intestinal juice converts carbohydrates into glucose,fats into amino acids. The wall of the small intestine  has served finger like projections called villi having blood vessels. It helps to increase the surface area for the absorption of digested food. The digested food is absorbed by the blood and transported to all cells of body. Then the undigested food passes into large intestine.

In the large intestine: water is absorbed and the waste material is converted into faecal matter which removed through the anus.


Ques.38 What is respiration?

Ans.38 Respiration is the process by which food is burnt in the cells of body with the help of oxygen to release energy.


Ques.39 Differentiate between breathing and respiration?


Breathing Respiration
Breathing is the physical process of inhaling and exhaling air. Respiration is the chemical process of oxidation of food in cells to release energy.
During breathing the breathing apparatus is used for the exchange of gases with the surroundings. The exchange of gases in  the cells is done by diffusion across the cell membrane.


No energy is released during breathing,infact energy is used for breathing. Energy is released during respiration in  the cells.


Ques 40 What are the various types of respiration? Differentiaye between them.

Ans.  Various types of respiration are:

Aerobic respiration and anaerobic respiration

Aerobic Anaerobic
Take place in the presence of oxygen Take place in the absence of oxygen
The end products are carbon dioxide ,water and large amount of energy. The end products are ethanol, carbon dioxide and energy.
Large amount of energy in released.(36ATP per glucose molecule) Small amount of energy is released(2ATP molecule per glucose )
Take place in cytoplasm X mitochondria. Take place only in cytoplasm.
E.g all plants and animals show aerobic respiration E.g Yeast during fermentation and some bacteria & tired muscle cells.

Ques.41 Name the respiratory of following organisms?

Ans. Insects: trachea, spiracles

Bird: lungs

Fish : gills

Tadpole: Gills

Frog: skin in water, lungs on land

Human being: lings

Amoeba: Cell Membrane


Ques. 42 Draw a well labelled diagram of a respiratory system.

 Ans.42 Diagram




Ques.43 Name the organs of human respiratory system.


  • Nostrils
  • Nasal Chambers
  • Naso-pharynx
  • Trachea
  • Bronchi
  • Bronchioles
  • Two lungs
  • Alveoli
  • Diaphragm


Ques.44  With the help of flow chart state the oath ways of breakdown of glucose during respiration?




Ques.45 what is ATP ? Why it called energy currency of cell?

Ans. ATP is the energy for most cellular process. The energy released during the process of respiration is used to make ATP molecule from ADP and inorganic phosphate.

ADP + P ——> ADP ~  P= ATP

(P) = phosphate

ATP is adenosine triphosphate.  Whenever the cell requires energy for any process, it breaks down the ATP molecule into ADP and inorganic phosphate, this  releases energy which is used by the cell.



Ques.46  What advantages over an aquatic organism does a terrestrial organism have with regards to obtaining oxygen for respiration?

Ans.46. The terrestrial organism obtain oxygen from air around them for respiration. In the air, oxygen is 21% by volume. This is much more than which is dissolved in water. So, aquatic organisms have less amount of oxygen to access. So, terrestrial organisms have an advantage over the aquatic organisms for availability of oxygen.


Ques.47 Why is the rate of breathing faster in aquatic organisms?

Ans.47 The rate of breathing is faster in aquatic organism as compared to terrestrial organism to make up for the less amount of oxygen available to them.


Ques.48 How is CO2 and O2 transported in human being?

Ans.48 When the blood moves through alveoli of the lungs it releases carbon dioxide into the lungs and picks up oxygen from lungs. This oxygen combines with haemoglobin of the RBC’s to form oxy-haemoglobin. The blood moves to the tissue where it releases the oxygen to the cell and picks up the carbon dioxide to the cells. Most of the carbon dioxide dissolve in the plasma of the blood and carried toward the lungs for release.


Ques.49 How are lungs design in human beings to maximise the area for exchange of gases?

Ans.49 Within the lungs two passage divides into smaller and smaller tube which finally terminate in the balloon structure which are called alveoli. The alveoli the surface which the exchange of gases can take place. The wall of the alveoli contain an extensive network of blood vessels. If the alveoli spread out it would cover 80 metre square. So the alveoli would provide a very large surface area for efficient exchange of gases in lungs.


Ques.50 What would be consequences of deficiency of haemoglobin?

Ans.50 If there would be deficiency of haemoglobin in our blood we will suffer from anaemia during which we cannot do our regular work and get exotic easily.


Ques.51 Name the transporting medium in the human being?

Ans.51 Blood


Ques.52 Name the transporting system?

Ans.52 Circulatory System


Ques.53 What is circulatory  system made of?

Ans.53 The circulatory is made up of heart, arteries, veins, capillaries and blood.


Ques.54 What if composition of blood?

Ans.54 Blood consist of plasma, Red blood Cells, white blood cells and platelets.


Ques.55 State various functions of blood?


  1. It helps in transport of oxygen from lungs to all body parts.
  2. It helps in transport of carbon dioxide from tissues back to lungs.
  3. It helps in transport of digestive food from small intestine to all body parts.
  4. It helps to transport the hormones throughout the body whenever they are required.
  5. It helps to transport the nitrogenous waste material to the kidney for their excretion in form of urine.
  6. Blood also helps in distributing the heat of the body evenly throughout the body.
  7. It prevents the loss of blood from the body at the time of injury by blood clotting.
  8. It helps protecting from many diseases and provide us immunity against infections.


Ques.56 Why is blood called fluid connective tissues?

Ans.56 Blood is a form of connective tissue as it connects all the body parts since it is in fluid form it is called the fluid connective tissue.


Ques.57 Draw a well labelled diagram of human heart?



Ques.58 Name different type of blood vessels present in the circulatory system?


  • Arteries
  • Veins
  • Capillaries


Ques.59 State function of capillaries?

Ans.59 They are very narrow blood vessels which connect arteries and veins together. The exchange of food, water, oxygen, carbon dioxide etc between the blood and the cell takes place through capillaries.


Ques.60 Differentiate between arteries and veins?


Arteries Veins
1. Arteries carry blood away from heart. 1. Veins carry blood towards heart.
2. Carry oxygenated blood except pulmonary artery. 2. Veins carry deoxygenated blood except pulmonary veins.
3. Arteries have thick and muscular walls. 3. Veins have thin walls as compared to arteries.
4. Arteries does not have any valves in them. 4. Veins have valves inside their lumen.
5. Arteries have narrow lumen. 5. Veins have broad lumen.
6. Arteries are deep seated. 6. Veins are superficial.
7. Blood flows under pressure in arteries. 7. In veins blood is not under pressure.


Ques61. Explain the structure and function of human heart?

Ans.61 It is a muscular organ which pumps blood to all parts of body. It has 4 chambers. The upper chambers are called atrium and lower chambers are called ventricles. Since the ventricles pump blood to different organs its walls are thicker than the atrium. The right and the left chamber are separated by the septum. It prevents mixing of oxygenated and deoxygenated blood. The atrium and ventricles have valves between them to prevent blood flowing backward.

Working- When the left atrium releases oxygenated blood from the lungs flow into it through the pulmonary vein. When it contracts, the left ventricle expands and the blood is pumped out through the aorta to all parts of the body. After circulating through all parts of the body the deoxygenated blood enters the right atrium through the vena cava. When the right atrium contracts the right ventricle contracts and the blood is pumped to lungs through pulmonary artery. In the lungs CO2 is removed and oxygen is absorbed and the oxygenated blood again enters the left atrium and the process repeats.


Ques.62 What is double circulation of blood?

Ans.62 Since blood flows through heart twice in one cycle, it is called double circulation.


Ques.63 What is lymph? State its function?


  • It is a colourless fluid present in the intercellular spaces. It is formed from the plasma which escapes from the capillaries. Lymph drains into lymphatic capillaries which forms lymph vessels and joins into large veins.
  • Lymph transports digested fats and drains excess fluids from intercellular spaces back into the blood. It contains lymphocytes which kills germs and protects the body.


Ques.64 How many heart chambers a heart has in the following animals? Fish,Frogs,Snakes,Crocodile,Birds,Mammals,Reptiles


Fish- 2 chambers in heart, one ventricle and one atrium.

Frogs and Snakes- Have 3 chambers. 2 atrium and 1 ventricle

Crocodile, birds and mammals- 4 chambers. 2 atrium and 2 ventricles

Reptiles- They have 3 chambers


Ques.65 What is the advantage of separation of left and right side of heart?

Ans.65 This prevents mixing of oxygenated and deoxygenated blood and provides efficient supply of oxygen. This is necessary because they need more energy to maintain their body temperature.


Ques.66 What is blood pressure? Name the instrument used to measure it?

Ans.65 The force that blood exerts on walls of vessels is called blood pressure. It is greater in arteries than in veins. It is measured by sphygmomanometer.


Ques.67  What is the normal blood pressure of human adult?

Ans.67 The normal Blood Pressure of human adult is 80mm-120mm of Mercury. 120mm is the systolic blood pressure and 80mm is the diastolic blood pressure.


Ques.68 What is hypertension? How is it caused? What are its effects?

Ans.68 Hypertension is high blood pressure when blood pressure of a person is higher than 140 over 90 mm of Mercury is considered as hypertension. It can cause sweat, headache, fits and heart attack.


Ques.69 State the functions of Red Blood Cells, White Blood Cells and Platelets?


Red Blood Cells helps in carrying oxygen with the help of haemoglobin from the lungs to all parts of the body.

White Blood Cells provide immunity to our body which means resistance to various diseases.

Platelets bring about clotting of blood at times of injury and prevents blood loss.


Ques.70 What is excretion?

Ans.70 Excretion is the removal of waste material from the body.


Ques.71 What are the various excretory products in human beings?

Ans.71 The various products are nitrogenous waste materials, digestive waste, oil, water which dissolves substances like Carbon Dioxide, Tears, Wax.


Ques.72 How are waste excreted from human body?

Ans.72 Nitrogenous waste urea are excreted in the form of urine.

Digestive wastes are excreted in the form of faecal.

Oil is excreted through oil glands present in skin.

Water and dissolved salts excreted through sweat glands in skin.

Tears are excreted from eyes along with other fluids.

Wax is excreted through the ears while CO2 is removed from the lungs during breathing i.e. exhalation.


Ques.73 Name the organs of excretory system of human beings?

Ans.73 It consists of following

  • A pair of kidneys
  • 2 ureters, 1 from each kidney.
  • 1 urinary bladder
  • Urethra


Ques.74 Draw a well labelled diagram of excretory system?



Ques.75 How is urine formed?

Ans.75 Nitrogenous waste such as urea or uric acid are removed from blood in the kidneys. It is then no surprise that the basic filtration unit is the kidney like in the lungs, is a cluster of very thin-walled blood capillaries. Each capillary cluster in the kidney is associated with the cup-shaped end of tube that collects is the filtered urine. Each kidney has large number of these filtration units called nephrons packed close together. Some substances in the initial filtrate, such as glucose, amino acid, salt and a major amount of water, are selectively reabsorb as the urine flows along the tube. The amount of water reabsorb depends on how much excess water there in the body, and on how much dissolved waste there is to be excreted. The urine forming in each kidney eventually enters a long tube, the water, which connects the kidney with the urinary bladder until the pressure of the expanded leads to the urge to pass it out through the urethra. This bladder is muscular, so it under nervous control. As a result we can usually control the urge to urinate.


Ques.76 Draw a well labelled diagram of nephron?



Ques.77 What is haemodialysis?

Ans.77 Haemodialysis is device to remove nitrogenous waste products from the blood when both the kidneys are manufacturing. It is also called artificial kidney.


Ques.78 Why is haemodialysis required in some people?

Ans.78 In some people there is infection injury or restricted blood flow to the kidneys, this reduce the activity of kidney which to accumulation of poisonous nitrogenous waste in the body. In case of kidney failure due to these reasons, the person has to be put on haemodialysis.


Ques.79 Name the basic unit of kidneys?

Ans.79 The basic unit of kidney is nephron.

There are around 1 million nephorns per kidney. In these nephrons the blood gets filtered and nitrogenous waste are removed from urine.


Ques.80 Explain the working of artificial kidney (haemodialysis)?

Ans.80 Artificial kidney contains a number of tubes with a semi permeable living lining suspended in a tank filled with dialysis fluid, this fluid has some osmotic pressure as blood, except that it is devoid of nitrogenous waste. The patients blood is passed through these tubes during this passage, the water products from the blood pass into the dialysing fluid by diffusion. The purified blood is pumped back into the patient, this is similar to the function of kidney, but it is different since there is no re-absorption involved. Normally in the healthy adult, the initial filtration in the kidney is about 180 litres daily. However the volume actually excreted in only a litre or two a day because the remaining is reabsorbed in the kidney tubules.


Ques.81 Name some excretory products of plants?


  • Oxygen
  • Water vapour
  • Carbon Dioxide
  • Latex
  • Gums/Raisins
  • Tannins
  • Calcium Oxalate crystals


Ques.82   How do plant get rid of their by-production?

Ans.82    Gaseous waste like CO2 , O2 and water vapour are removed through the stomata of leaves. Some wastes are released from the roots of the plant in the surrounding soil. Waste like  latex, gums, resins are secreted through lenticels of the stems and many waste are stored in leaves like tannins, crystals etc. When plant shed their leaves they get rid of these waste and bear new leaves.

Ques.83 how is the amount of wine produced regulated?

Ans.83 The amount of  wine produced is regulated by the action hormones on the nephron which allows the re-absorption of water accordingly thereby controlling the amount of wine produced.

Ques.84 Name the vascular tissues in the plants and state their function?

Ans.84  The vascular tissues in the plant are made up of xylem and phloem. Xylem transports water and minerals from soil through the roots to all parts of plant especially the leaves. Phloem transport prepared food from leaves  to all parts. This process is called translocation.

Ques.85 How does water move up a tall tree?

Ans.85 Water from the soil is first absorbed through root hair with the help of this root pressure it moves up to 2 meters  height from where it is pulled up by suction pressure created by transpiration pull, so transpiration is a necessary evil for plants as it helps in the uptake of water and loss of water also.

Ques.86 Differentiate between xylem and phloem.


Xylem Phloem
Xylem transports water and minerals to all parts of plants Phloem transport prepare food from the leaves to all parts of the plants.


The transport in xylem is unidirectional i.e from roots to all parts(leaves) Transport direction is bi- directional
Transport in xylem results in transpiration through the leaves. Transport in phloem result in storage of food in organs storage.


Ques.87 What is transpiration? State factor affecting it what are its advantages?

Ans.87  Transpiration is the process of evaporation of water through the stomata of the leaves factor affecting transpiration are temperature , humidity, wind speed. Rate of transpiration increase with increase in temperature, decrease in humidity and increase in wind speed and vice-versa.


  1. Transpiration helps on uptake of water by the trees.
  2. Transpiration helps in cooling down of water.
  3. Transpiration also helps in bringing rain
  4. It also keeps leaf surface cool and prevents it from burning.


Ques. 88 What is transpiration? How does it takes place?

Ans.88 transpiration is the process of transportation of food through phloem in plants. Unlike transports in xylem which can be largely explained by simple physical force the translocation in phloem is achieved by utilizing energy. Material like sucrose is transferred into phloem tissue using energy from ATP. This increases the osmotic pressure of this tissue causing water to move into it. This pressure moves the material in the phloem to tissues which have less pressure. This allows phloem to move material according the plant need for example, in sparing, sugar stored in root or stem tissue would be transported to the buds which need energy to grow.

Ques.89 Compare the functioning of alveoli in the lings and nephrons in kidney with respect to their structure functioning ?


Alveoli Nephrons in kidney
Structure:- they are sac like structure present at end of bronchioles. They are supplied by blood vessels. Structure:- Nephrons have a cup shaped gloucerices  in which capillaries are present. The bomens capsules has tubules attached to it.


Functions:- Exchange of gases takes place in the alveoli during breathing process. Functions:- the blood is filtered of the nitrogenous waste material and wine is formed.





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