Nutrition in Animals
 MULTIPLE CHOICE QUESTIONS 1. Given below from (i) to (iv) are some food items.
 (i) Boiled and mashed potato (ii) Glucose solution (iii) A slice of bread (iv) Mustard oil Which of the above will give blue-black colour when tested with iodine?
 (a) (i) and (ii) (b) (i) and (iii) (c) (ii) and (iii) (d) (iii) and (iv)

 2. Which of the following pair of teeth differ in structure but are similar in function?
(a) canines and incisors. (b) molars and premolars. (c) incisors and molars. (d) premolars and canines.

 3. Read carefully the terms given below. Which of the following set is the correct combination of organs that do not carry out any digestive functions?
(a) Oesophagus, Large Intestine, Rectum (b) Buccal cavity, Oesophagus, Rectum (c) Buccal cavity, Oesophagus, Large Intestine (d) Small Intestine, Large Intestine, Rectum

4. The swallowed food moves downwards in the alimentary canal because of
 (a) force provided by the muscular tongue. (b) the flow of water taken with the food. (c) gravitational pull. (d) the contraction of muscles in the wall of food pipe.

 5. The acid present in the stomach
 (a) kills the harmful bacteria that may enter along with the food. (b) protects the stomach lining from harmful substances. (c) digests starch into simpler sugars. (d) makes the medium alkaline.

 6. The finger-like outgrowths of Amoeba helps to ingest food. However, the finger-like outgrowths of human intestine helps to
(a) digest the fatty food substances. (b) make the food soluble. (c) absorb the digested food. (d) absorb the undigested food.

 7. Read the following statements with reference to the villi of small intestine.
 (i) They have very thin walls. (ii) They have a network of thin and small blood vessels close to the surface. (iii) They have small pores through which food can easily pass. (iv) They are finger-like projections. Identify those statements which enable the villi to absorb digested food.
(a) (i), (ii) and (iv) (b) (ii), (iii) and (iv) (c) (iii) and (iv) (d) (i) and (iv)

 8. The false feet of Amoeba are used for
 (a) movement only. (b) capture of food only. (c) capture of food and movement. (d) exchange of gases only.

 9. The enzymes present in the saliva convert
 (a) fats into fatty acids and glycerol. (b) starch into simple sugars. (c) proteins into amino acids. (d) complex sugars into simple sugar

 10. Cud is the name given to the food of ruminants which is
 (a) swallowed and undigested. (b) swallowed and partially digested. (c) properly chewed and partially digested. (d) properly chewed and completely digested.

11. Choose the correct order of terms that describes the process of nutrition in ruminants.
 (a) swallowing → partial digestion → chewing of cud → complete digestion (b) chewing of cud → swallowing → partial digestion → complete digestion (c) chewing of cud → swallowing → mixing with digestive juices → digestion (d) swallowing → chewing and mixing → partial digestion → complete digestion



. VERY SHORT ANSWER QUESTIONS
12. Name the parts of the alimentary canal where
 (i) water gets absorbed from undigested food. (ii) digested food gets absorbed. (iii) taste of the food is perceived. (iv) bile juice is produced.

 13. Mark the following statements as True or False. If false, write the correct statements.
 (a) Tongue is attached to the roof of the mouth cavity at the back.
 (b) The large intestine is longer and wider than the small intestine of the human alimentary canal.
 (c) Mucus protects the stomach lining from damage.
 (d) All heterotrophs have a similar basic process of nutrition.

14. Choose the odd one out from each group and give reasons
. (i) liver, salivary gland, starch, gall bladder (ii) stomach, liver, pancreas, salivary gland (iii) tongue, absorption, taste, swallow (iv) oesophagus, small intestine, large intestine, rectum

 15. You were blindfolded and asked to identify the drinks provided in two different glasses. You could identify drink A as lime juice and B as bitter gourd juice. How could you do it inspite of being blindfolded?

16. Fill in the blanks with suitable words:
(a) The alimentary canal stretches from  _________ to __________.
 (b) Digestion of food starts in________ and gets completed in ___________.
 (c)_________ is the largest gland in the human body.

 17. Following statements describe the five steps in animal nutrition.
 Read each statement and give one word for each statement. Write the terms that describes each process.
(a) Transportation of absorbed food to different parts of body and their utilisation.
(b) Breaking of complex food substances into simpler and soluble substances.
 (c) Removal of undigested and unabsorbed solid residues of food from the body.
 (d) Taking food into the body.
 (e) Transport of digested and soluble food from the intestine to blood vessels.

CLASS 9 EVAPORATION (HINTS GIVEN IN THE END)
1Water as ice has a cooling effect, whereas water as steam may cause severe burns. Explain these observations.

2 Alka was making tea in a kettle. Suddenly she felt intense heat from the puff of steam gushing out of the spout of the kettle. She wondered whether the temperature of the steam was higher than that of the water boiling in the kettle. Comment

3.(a) Conversion of solid to vapour is called sublimation. Name the term used to denote the conversion of vapour to solid.
(b) Conversion of solid state to liquid state is called fusion; what is meant by latent heat of fusion?

4It is a hot summer day, Priyanshi and Ali are wearing cotton and nylon clothes respectively. Who do you think would be more comfortable and why?

5  You want to wear your favourite shirt to a party, but the problem is that it is still wet after a wash. What steps would you take to dry it faster?

6Comment on the following statements: (a) Evaporation produces cooling.
 (b) Rate of evaporation of an aqueous solution decreases with increase in humidity.

7Which condition out of the following will increase the evaporation of water? (a) Increase in temperature of water (b) Decrease in temperature of water (c) Less exposed surface area of water (d) Adding common salt to water


Multiple Choice Questions 1. Which one of the following sets of phenomena would increase on raising the temperature? (a) Diffusion, evaporation, compression of gases (b) Evaporation, compression of gases, solubility (c) Evaporation, diffusion, expansion of gases (d) Evaporation, solubility, diffusion, compression of gases

2. Seema visited a Natural Gas Compressing Unit and found that the gas can be liquefied under specific conditions of temperature and pressure. While sharing her experience with friends she got confused. Help her to identify the correct set of conditions (a) Low temperature, low pressure (b) High temperature, low pressure (c) Low temperature, high pressure (d) High temperature, high pressure

 3. The property to flow is unique to fluids. Which one of the following statements is correct? (a) Only gases behave like fluids (b) Gases and solids behave like fluids (c) Gases and liquids behave like fluids (d) Only liquids are fluids

4. During summer, water kept in an earthen pot becomes cool because of the phenomenon of (a) diffusion (b) transpiration (c) osmosis (d) evaporation

 5. A few substances are arranged in the increasing order of ‘forces of attraction’ between their particles. Which one of the following represents a correct arrangement? (a) Water, air, wind (b) Air, sugar, oil (c) Oxygen, water, sugar (d) Salt, juice, air

6. On converting 25°C, 38°C and 66°C to kelvin scale, the correct sequence of temperature will be (a) 298 K, 311 K and 339 K (b) 298 K, 300 K and 338 K (c) 273 K, 278 K and 543 K (d) 298 K, 310 K and 338 K

 7. Choose the correct statement of the following (a) conversion of solid into vapours without passing through the liquid state is called vapourisation. (b) conversion of vapours into solid without passing through the liquid state is called sublimation. (c) conversion of vapours into solid without passing through the liquid state is called freezing. (d) conversion of solid into liquid is called sublimation

. 8. The boiling points of diethyl ether, acetone and n-butyl alcohol are 35°C, 56°C and 118°C respectively. Which one of the following correctly represents their boiling points in kelvin scale? (a) 306 K, 329 K, 391 K (b) 308 K, 329 K, 392 K (c) 308 K, 329 K, 391 K (d) 329 K, 392 K, 308 K

 9. Which condition out of the following will increase the evaporation of water? (a) Increase in temperature of water (b) Decrease in temperature of water (c) Less exposed surface area of water (d) Adding common salt to water

10. In which of the following conditions, the distance between the molecules of hydrogen gas would increase? (i) Increasing pressure on hydrogen contained in a closed container (ii) Some hydrogen gas leaking out of the container (iii) Increasing the volume of the container of hydrogen gas (iv) Adding more hydrogen gas to the container without increasing the volume of the container

(a) (i) and (iii) (b) (i) and (iv) (c) (ii) and (iii) (d) (ii) and (iv)
HINT1
In case of ice the water molecules have low energy while in the case of steam the water molecules have high energy. The high energy of water molecules in steam is transformed as heat and may cause burns. On the other hand, in case of ice, the water molecules take energy from the body and thus give a cooling effect.
. The temperature of both boiling water and steam is 100°C, but steam has more energy because of latent heat of vapourisation.(a) The water will cool initially till it reaches 0°C, the freezing point. At this stage the temperature will remain constant till all the water will freeze. After this temperature would fall again.
4 The rate of evaporation increases with an increase of surface area because evaporation is a surface phenomenon. Also, with the increase in air speed, the particles of water vapour will move away with the air, which will increase the rate of evaporation.Conditions that can increase the rate of evaporation of water are (a) an increase of surface area by spreading the shirt (b) an increase in temperature by putting the shirt under the sun (c) increase the wind speed by spreading it under the fan.
.6 (a) Evaporation produces cooling as the particles at the surface of the liquid gain energy from the surroundings and change into vapour thereby producing a cooling effect.
 (b) Air around us cannot hold more than a definite amount of water vapour at a given temperature which is known as humidity. So, if the air is already rich in water vapour, it will not take up more water therefore, rate of evaporation of water will decrease.

1 In case of ice the water molecules have low energy while in the case of steam the water molecules have high energy. The high energy of water molecules in steam is transformed as heat and may cause burns. On the other hand, in case of ice, the water molecules take energy from the body and thus give a cooling effect.
The temperature of both boiling water and steam is 100°C, but steam has more energy because of latent heat of vapourisation

CLASS 9 PRACTICALSKILLS

1] To determine the melting point of ice a student immersed the thermometer in thecrushed ice in a beaker. He then heated the beaker on a low flame and observed that during melting of ice the temperature :
A.   Is decreasing
B. Fist decreases and then continuously increases
C.  Is increasing
D. Remains constant Ö

2] In the mixture of iron filings and sulphur powder
A. both sulphur powder and iron filings gets attracted towards magnet
B.only sulphur powder gets attracted towards magnet
C.Neither iron filling nor sulphur gets attracted towards magnet.
D.only iron filings gets attracted towards magnet Ö

3] When a mixture of sulphur powder and iron filings is heated.
A. iron filings starts melting
B.sulphur sublimates leaving iron filling behind
C.sulphur melts
D. Ferrous sulphide is formed. Ö

4] A student added milk, white of an egg, common salt and sand separately to water kept in four separate beakers. He stirred the mixtures well and filtered each of them. On filtering, he obtained solid residue on the filter paper in case of :
A.    Milk
B.  White of an egg
C. Common salt
D.  Sand Ö

5] A student sets up an apparatus for determining the boiling point of water. He records the temperature after regular intervals and finds that water when it begins to boil:
A. Continuously rises
B.First remains constant and then rises
C.Remains constant
D.First rises and then becomes constant Ö

MATTER IN OUR SURROUNDING  CLASS IX

• List the important characteristics of matter

• Difference among solid, liquid and gas.

• List any five physical properties of liquids

• Classify the matter in terms of physical state and composition

• Simple and clear-cut definitions along with the differences between the following terms:

• Evaporation
• Sublimation
• Condensation

• Difference between latent heat of fusion and latent heat of vaporization

• What do you mean by volatile liquid?

• Definitions of melting point, boiling point and freezing point

• Read clearly about the sublimation process

• Identify the matter from the given terms:

Chair, Air, Love, Smell, Hate, Almonds, Thought, Cold, Cold drinks, Smell of perfume

• The smell of hot sizzling food reaches you several meters away, but to smell the cold food you have to get close to it. Give the logical explanation for the same

• What is Diffusion, and why gases diffuse rapidly?

• The mass per unit volume of a substance is called density (density=mass/volume). Arrange the following in order of increasing density:

     Air, Exhaust from chimneys, Honey, Water, Chalk, Cotton, and Iron

• Explain the application of compressibility in gases with an example

• Define the term evaporation

• Mention the uses of LPG and CNG

• What is SI unit of temperature? Give mathematical relation also

• Convert the following temperatures to Celsius scale:

     (a) 333 K

     (b) 473 K

• What is absolute temperature

• Which state of matter is most easily compressible

• A diver is able to cut through water in a swimming pool. Identify which property of matter is working here?

• Arrange the following substances in increasing order of intermolecular force of attraction:

     Water, Sugar, Oxygen

• Give reasons to justify:

     (a) Water at room temperature is in liquid form

     (b) An iron almirah is in solid form

• Diffusion becomes faster at higher temperatures. Why?

• Boiling is considered as bulk phenomenon. Why?

• Why does the temperature of a substance remains constant during melting and boiling even when heat is being supplied to it continuously?

• What factors affect the rate of evaporation?

• In which case evaporation of water will be faster; near the sea or far away from the sea.

• What do you mean by solid ice? Why CO2 is kept under low pressure

class 9 chemistry revision
MATTER IN OUR SURROUNDINGS
List two processes from which it may be concluded that the particles of a gas move continuously.

Ans: Compressibility and Brownian movement

Q. At what temperature does solid ice and liquid water co-exist together?  

Ans: At 00C, the  phases of water co exist called triple point.

Q. What is common among the three states of matter?

Ans: They all contain molecules.

Q. . Which property of gas is used in supplying oxygen cylinders to hospitals? 

Ans: Compressibility

Q. a substance x was highly compressible and could easily be liquefied. it could also take the shape of the container. Predict  the nature of the substance

Ans: 

Q. can a liquid turn into vapor without heating?

Ans: yes, By the process of evaporation as vaporization of water occur  below the boiling point under atmospheric pressure.

Q. What do you mean by Latent heat of Fusion?

Ans:  the heat required to change 1 kg of a solid substance into liquid state at the melting point of the substance. For example, amount of heat required to melt ice at 0 ° C into water, at 0 ° C will be known as the Latent Heat of Fusion of ice.

Q. What is compressibility? How it is negligible in solids?

Ans: Compressibility is the ability of a substance  to be reduced to its  volume under pressure. Solids are incompressible as their particles are held together. So, we can tell that compressibility is negligible in solids. 

Q. Two cubes of ice are pressed hard between two palms. After releasing the pressure, the cubes join together. Why?

Ans: Pressure is directly proportional to temperature  when we apply pressure, temp. Increases then the ice in contact melts and  it turns into water.  when pressure is removed, the temperature decreases again and  melted ice again freezes .Hence cubes join together.

Q. Explain why ice has lower density than water?

Ans: The mass per unit volume of a substance is called density (density = mass/volume). As the volume of a substance increases, its density decreases.

When water changes into ice, space between particles increases. These spaces are larger as compared to the spaces present between the particles of water. Thus, the volume of ice is become greater than that of water. Hence, the density of ice became lower than that of water. As, a substance with lower density than water can float on water. Therefore, icefloats on water

class 8
cell stucture

CHEMICAL EFFECTS OF ELECTRIC CURRENT

I. Write answer for the following as directly :

1. What is LED ?

2. Name a gas which burns with a pop sound.

3. Which electrode is connected to the negative terminal of a cell ?

4. Name the ions which are positively charged.

5. Name a device which is used for the electrolysis of water ?

6. Identify the following as electrolytes and non electrolytes :

a) dil HNo3 b) Benzene c) Petrol d) Zinc Chloride solution e) a solution of Naoh g) Ether h) Alcohol i) Common salt solution

7. State three uses of electrolysis.

8. Draw a neat diagram of voltameter and label it

class 7 science
Nutrition in animals

1. Fill in the blanks:

(a) The main steps of nutrition in humans are __________, __________, __________, _________ and __________.
(b) The largest gland in the human body is __________.
(c) The stomach releases hydrochloric acid and ___________ juices which act on food.
(d) The inner wall of the small intestine has many finger-like outgrowths called _________.
(e) Amoeba digests its food in the ____________ .

Mark T if the statement is true and F if it is false:

(a) Digestion of starch starts in the stomach. (T/ F)
(b) The tongue helps in mixing food with saliva. (T/ F)
(c) The gall bladder temporarily stores bile. (T/ F)
(d) The ruminants bring back swallowed grass into their mouth and chew it for some time.

3. Tick (✓) mark the correct answer in each of the following:

(a) Fat is completely digested in the
       (i) stomach      (ii) mouth      (iii) small intestine     (iv) large intestine

(b) Water from the undigested food is absorbed mainly in the
       (i) stomach       (ii) foodpipe       (iii) small intestine      (iv) large intestine

4. Match the items of Column I with those given in Column II:

Column I Food Components	Column II Product(s) of digestion
Carbohydrates	Fatty Acids and Glycerol
Proteins	Sugar
Fats	Amino acids

7. Name the type of carbohydrate that can be digested by ruminants but not by humans. Give the reason also.

Answer

Cellulose is a type of carbohydrate that can be digested by ruminants and not by humans. 
Ruminants have a large sac-like structure called rumen between the oesophagus and the small intestine. The cellulose of the food is digested here by the action of certain bacteria which are not present in humans.

8. Why do we get instant energy from glucose?

Answer

Glucose is simple sugar which is formed when carbohydrate get broken. Also, the carbohydrate get digested into glucose. Since, glucose does not have to be digested and thus acts as an instant source of energy.
9. Which part of the digestive canal is involved in:

(i) absorption of food ________________.
(ii) chewing of food ________________.
(iii) killing of bacteria ________________.
(iv) complete digestion of food ________________.
(v) formation of faeces ________________.