CLASS-11 SUBJECT-BIOLOGY CHAPTER-12 MINERALS NUTRITION(TRANSPORT IN PLANTS)

 EVENTS CONVENT HIGH SCHOOL

29/09/2021      CLASS-11     SESSION 2021-22
SUBJECT :BIOLOGY

CHAPTER-12
TRANSPORT IN PLANTS

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Question 1.
“All elements that are present in a plant need not be essential to its survival”. Comment.
Solution:
Plants obtain their inorganic nutrients from the air, water, and soil. Plants absorb a wide variety of mineral elements. Not all the mineral elements that they absorb are required by plants. Out of the more than 105 elements discovered so far, less than 21 are essential and beneficial for normal plant growth and development. The elements required in large quantities are called macronutrients. While those required in fewer quantities or in the trace are termed micronutrients. These elements are either essential constituents of proteins, carbohydrates, fats, nucleic acid, etc. and/or take part in various metabolic processes.

Question 2.
Why is the purification of water and nutrient salts so important in studies involving mineral nutrition using hydroponics?
Solution:
The technique of growing plants in a nutrient solution is known as hydroponics. Since a number of improvised methods have been employed to try and determine the mineral nutrients essential for plants. The essence on all these methods involves the culture of plants in a soil-free, defined mineral solution. These method require purified water and mineral nutrients salts. Purification of water and nutrient salt is important to find out other influencing factors

Question 3.
Explain with examples:
Macronutrients, micronutrients, beneficial nutrients, toxic elements, and essential elements.
Solution:
Based upon the criteria only a few elements have been found to be absolutely essential for plant growth and metabolism. These elements are further divided into two broad categories based on their quantitative requirements,

1. Macronutrients
2. Micronutrients

Macronutrients must generally be present in plant tissues in the concentration of 1 to 10 mg/L of dry matter. The macronutrients include carbon, hydrogen, oxygen, nitrogen, phosphorous, sulfur, potassium, calcium, and magnesium. Of these, carbon, hydrogen, and oxygen are mainly obtained from CO2, and H20, while the others are absorbed from the soil as mineral nutrition.

Micronutrients or trace elements are needed in very small amounts (equal to or less than 0.1 mg/L of dry matter). These include iron, manganese, copper, molybdenum, zinc, boron, chlorine, and nickel. In addition to the 17 essential elements named above, there are some beneficial elements such as sodium, silicon, cobalt, and selenium. They are required by higher plants.

Essential elements can also be grouped into four broad categories on the basis of their diverse functions. These categories are:
(1) Essentia] elements as components of biomolecules and hence structural elements of cells, (eg: carbon, hydrogen, oxygen, and nitrogen).

(2) Essential elements that are components of energy-related chemical compounds in plants, for example, magnesium in chlorophyll and phosphorous in ATP.

(3) Essential elements that activate or inhibit enzymes, for example, Mg2+ is an activator for both ribulose bisphosphate carboxylase-oxygenase and phosphoenolpyruvate carboxylase, both of which are critical enzymes in photosynthetic carbon fixation; Zn2+ is an activator of alcohol dehydrogenase and Mo of nitrogenase during nitrogen metabolism.

(4) Some essential elements can alter the osmotic potential of a cell. Potassium plays an important role in the opening and closing of stomata. Any mineral ion concentration in tissues that reduces the dry weight of tissues by about 10 percent is considered toxic. Such critical concentrations vary widely among different micronutrients. The toxicity symptom! are difficult to identify.

Toxicity levels for any element also vary for different plants. Many times excess of an element may inhibit the uptake of another element. For example, the prominent symptoms of manganese toxicity are the appearance of brown spots surrounded by chlorotic veins.

Question 4.
Name at least five different deficiency symptoms in plants. Describe them and correlate them with the concerned mineral deficiency.
Solution:

1. Chlorosis: Chlorosis is the loss of chlorophyll leading to yellowing in leaves. It is caused by a deficiency of N, K, Mg, S, Fe, Mn, Zn, and Mo.
2. Necrosis: It is the death of tissue. It occurs due to deficiency of Ca, Mg, Cu, K.
3. Inhibition of cell division: It occurs due to deficiency of N, K, S, Mo.
4. Stunted plant growth: It occurs due to deficiency of Ca, N, etc.
5. Premature fall of leaf and buds: It occurs due to deficiency of calcium, magnesium.

Question 5.
If a plant shows a symptom which could develop due to deficiency of more than one nutrient, how would you find out experimentally, the real deficient mineral element?
Solution:

1. The deficiency symptoms can be distinguished on the basis pf the region of occurrence, presence or absence of dead spots, and chlorosis of entire leaf or interveinal chlorosis.
2. The region of the appearance of deficiency symptoms depends on the mobility of nutrients in plants. The nutrient deficiency symptoms of N, P, K, Mg, and Mo appear in lower leaves.
3. Zinc is moderately mobile in plants and deficiency symptoms, therefore, appear in middle leaves.
4. The deficiency symptoms of less mobile elements (S, Fe, Mn, and Cu) appear on new leaves.
5. Ca and B are immobile in plants, deficiency symptoms appear on terminal buds.
6. Chlorine deficiency is less common in crops.
   

Question 6.
Why is it that in certain plants deficiency symptoms appear first in younger parts of the plant while in other they do so in mature organs?
Solution:
The deficiency symptoms tend to appear first in the young tissues whenever the elements are relatively immobile and are not transported out of the mature organs, for example, elements like sulphur and calcium are a part of the structural component of the cell and hence are not easily released.

Question 7.
How are the minerals absorbed by the plants?
Solution:
Uptake of mineral ions, by plants, occurs through
two main phases.
Passive Absorption: It is the process of absorption of minerals through it’s outer space(Intercellular space and cell wall) by physical process. Direct expenditure of metabolic energy is not involved. A substance moves from a region of higher chemical potential to lower chemical potential. It occurs through ion channels (transmembrane protein). The theories to explain the movement of ions:
(a) Ion exchange: Both cation and anion gets absorbed on the surface of cell wall. The absorbed ions are exchanged with ions present in soil solution.
(b) Mass flow hypothesis: According to this hypothesis mass flow of ions occur along with absorption of water as a result of transpirational pull.
Active Absorption: It is the process of movement of ions against a concentration gradient, by utilizing ATP as energy. Both influx and efflux of ions are carried out by carrier mechanism. The activated ions combine with carrier proteins and form ion carrier complex. This complex moves
across all the membrane and reaches inner surface, where it breaks and releases ions into the cytoplasm.

Question 8.
What are the conditions necessary for the fixation of atmospheric nitrogen by Rhizobium? What is their role in nitrogen fixation?
Solution:
Rhizobia are unique because they live in a symbiotic relationship with legumes. Necessary conditions:

• Requires a strong reducing agent and energy in the form of ATP.
• The enzyme nitrogenase which is very sensitive to oxygen is required.
• The processes take place in an anaerobic environment
• The energy is provided by the respiration of host cells.

The reduction of nitrogen to ammonia by living organisms is called biological nitrogen fixation. The enzyme, nitrogenase which is capable of nitrogen reduction is present exclusively in prokaryotes. Several types of symbiotic biological nitrogen-fixing associations are known. The most common association on roots is nodules. Their role in N2– fixation is to supply the plants with nitrogenase that converts nitrogen to amino acids.

Question 9.
What are the steps involved in the formation of root nodule?
Solution:
Nodule formation involves a sequence of multiple interactions between Rhizobium and the roots of the host plant. Stages in the nodule formation are summarised as follows:
Steps in the development of root nodules:
(a) When a root hair of a leguminous plant comes in contact with Rhizobium, it is deformed due to the secretion from the bacterium.
(b) At the site of curling Rhizobia invades the root tissue and proliferate within root hairs.
(c) Some bacteria enlarge to form membrane-bound structures, bacteroids which cannot divide.
(d) The plants form the infection thread, made up of plasma membrane that grows inward, separating the infected tissue from the rest of the plant.
(e) Cell division is stimulated in the infected tissue and more bacteria invade the newly formed tissues.
(f) It is believed that a combination of cytokinin produced by invading bacteria and auxins produced by plant cells, promotes cell division and extension, leading to nodule formation.
Question 10.

Which of the following statements are true? If false correct them:
(a) Boron deficiency leads to the stout axis.
(b) Every mineral element that is present in a cell is needed by the cell.
(c) Nitrogen as a nutrient element, is highly immobile in plants.
(d) It is very easy to establish the essentiality of micronutrients because they are required only in trace quantities.
Solution:
(a) True
(b) False
Correct sentence: Every mineral element that is present in a cell is not needed by the cell.
(c) False
Correct sentence: Nitrogen as a nutrient element is highly mobile in the plants.
(d) False
Correct sentence: It is very difficult to establish the essentiality of micronutrients because they are required only in trace quantities.

CLASS-11 SUBJECT ENGLISH SNAPSHOT CHAPTER-1 THE SUMMER OF THE BEAUTIFUL WHITE HORSE

 EVENTS CONVENT HIGH SCHOOL

29/09/2021      CLASS-11     SESSION 2021-22
SUBJECT :ENGLISH SNAPSHOT

CHAPTER-1
THE SUMMER OF THE BEAUTIFUL WHITE HORSE

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The Summer of the Beautiful White Horse Reading with insight

Question 1.You will probably agree that this story does not have breathless adventure and exciting action. Then what in your opinion makes it interesting?
Answer:
The thing of crazy streak in Garoghlanian family makes the story interesting. Uncle Khosrove repeated phrase to every petty or major loss, ‘Pay no attention to it. It’s no harm’, adds more interest in the story. Mourad’s innocence and his mysterious ways to tackle the ‘horse’, ‘dog1 and even ‘farmer’ make the story really very interesting.

Question 2.Did the boys return the horse because they were conscience-stricken or because they were afraid?
Answer:
The boys returned the horse as they were afraid. The narrator had come to know that the horse belonged to farmer John Byro whose surrey had become useless because of his lost horse for a month. He informed it to Mourad and asked him not to return the horse as he wanted to learn how to ride a horse properly first. But unluckily when they met John Byro on the way, they got afraid. They put it stealthily in Byro’s bam next morning.

Question 3.‘One day back there in the good old days when I was nine and the world was full of every imaginable kind of magnificence, and life was still a delightful and mysterious dream. The story begins in a mood of nostalgia. Can you narrate some interesting incident from your childhood that might make an interesting story?
Answer:
Once when I was still a student of Class IV, I had gone to pick fruits including berries, guava, and pomegranates in the garden of villager Mr. Ramdhan Tyagi. We were a pack of eight children. We all had eaten fruits to our fill. After that we all packed our pockets. As we were returning happily, uncle Ramdhan returned from his home after a nap in the noon. He naturally gave us a chase.

I being the youngest in the group, lagged behind and was caught. He asked ‘whose daughter are you?’ ‘Sh. Lekh Ram’, I replied. In the evening we all heard the sounds of great row at the home of Sh. Lekh Ram. Actually, romance at ‘hort notice was my speciality then. To save my skin from my parents I had told the name of a neighbour as my father.

Question 4.The story revolves around the characters that belong to a tribe in Armenia. Mourad and Aram are members of the Garoghlanian family. Now locate Armenia and Assyria on the atlas and prepare a write up on the Garoghlanian tribes. You may write about people, their names, traits, geographical and economic features as suggested in the story.
Answer:
The Garoghlanian tribes were scattered in the expanse of Assyria and Armenia in Asia continent sometime between the period of 500 B.C. to 800 B.C. Their main occupation was farming. They were famous for their honesty and trust. They were great nature-lovers. They never thought of stealing. They never bothered to attain more heights financially as well as physically. They were contented in their peaceful easy life. They never dreamt of taking advantage of others in the world.

The Summer of the Beautiful White Horse Extra Questions Short Answer Type 

Question 1.To which tribe did Aram and Mourad belong? What was particular about their tribe?
Answer:
Aram and Mourad belonged to Garoghlanian tribe. The tribe was well known for its honesty and trust. The people belonging to the tribe to neither be liars nor thieves.

Question 2.Why and when did Mourad take John Byro’s horse?
Answer:
Mourad was known for a crazy streak in his character. He was fond of horse riding. But he belonged to a poor family, He could never afford to realise his long cherished s dream of riding a horse. So one day he ‘stole’ John Byro’s horse. He kept it to his custody at * least a month, before he disclosed it to Aram.

Question 3.Why did Mourad bring the wonderful white horse to Aram?
Answer:
Mourad brought this horse to Aram, his cousin brother. He knew quite well that Aram was equally fond of riding a horse. Mourad himself had been enjoying joy-rides on the wonderful white horse since a month’s time. Now he wanted his cousin brother to enjoy the same.

Question 4.How did Mourad manage to keep his ‘deed’ a ‘secret’?
Answer:
Mourad would enjoy the joy-rides on the wonderful white horse only during the early morning hours. As soon as the day breaks, he would hide the horse in a deserted bam. There were some oats and dry alfalfa to satisfy the hunger of the horse.

Question 5.How did the narrator come to know about the real owner of the horse? What was his reaction?
Answer:
The narrator returned his home, after enjoying a ride on the wonderful white horse. An Assyrian visitor named John Byro came to his home and sighing sadly told that v his white horse was stolen for a month. Now the narrator realised the horse Mourad was . having those days, was actually Byro’s. He felt panicky and went to Mourad to disclose the news. But he requested him not to return the horse so early.

Question 6.Why did the boys not want to return the horse immediately? Did their wish fulfill?
Answer:
The boys didn’t want to return the horse immediately as both wanted to learn properly how to ride a horse. Mourad told Aram that he would keep it at least six months. But alas! Their wish couldn’t be fulfilled.

Question 7.Why did the boys return the horse so early?
Answer:
One morning the boys were taking the horse to its hiding place, after having a joy ride over it. They met John Byro; the real owner of the horse. John swore that the horse was the twin of his own one and some suspicious mind could take it to be his own as its teeth and everything were like those of his own one. At this the boys got panicky. Due to fear of disclosure of their dare deed, they put hack the horse the next day at its real owner’s bam.

Question 8.Who was John Byro? Why had he come to the narrator’s house?
Answer:
John Byro was an Assyrian by birth. He was a farmer. But he had learnt to speak Armenian also due to loneliness. Perhaps he had settled down somewhere in Armenia ten miles away from narrator’s home. He had come to the narrator’s house to vent out his woes over the loss of his only horse. His horse was missing for a month. .

Question 9.What impression do you form about Khosrove?
Answer:
Khosrove was an uncle to Mourad and Aram. He had acquired the special char-acteristic of the family i.e. the crazy streak. He was an enormous man with a powerful head of black hair. He had the largest moustache in entire San Joaquin Valley. He was quite an irritable fellow who lost his temper quite easily if somebody cried over his loss. His most repeated words (at such situation) were. It is no harm; pay no attention to it.”

Question 10.‘I couldn’t believe what I saw.’ What was there so incredible to the speaker? Who is the speaker here?
Answer:
The protagonist of the story ‘Aram’ is the speaker here. One fine summer pre day-break, his cousin brother Mourad had come to invite him on a wonderful white horse. The horse didn’t belong to him. So it was incredible to the speaker where from Mourad had got that horse, as he could not be a thief.

Question 11.How was the ‘deed’ of taking away somebody else’s horse and hiding it without the owner’s knowledge not a theft according to the boys?
Answer:
According to the boys, the horse which actually belonged to John Byro had been taken away by them just to enjoy joy rides. It can’t be called a ‘theft’ until they offered to sell the horse.

Class-8 Subject English Lesson-4 BIPIN CHOUDHURY'S LAPSE OF MEMORY.

 EVENTS CONVENT HIGH SCHOOL

29/09/2021      CLASS-8     SESSION 2021-22
SUBJECT :ENGLISH

LESSON-4
BIPIN CHOUDHURY'S LAPSE OF MEMORY

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Bepin Choudhury’s Lapse of Memory Comprehension check (Page 62)

Question 1.Why did the man stare at Bepin Babu in disbelief ?
Answer:
The man reminded Bepin Babu of was trip to Roneh. But Bepin Babu denied of his visit. This made the man. Therefore, he was staring at him in disbelief.

Question 2.Where did Bepin Babu say he went in October ’58 ?
Answer:
Bepin Babu said that he had gone to Kanpur at his friend’s place in October 58.

Question 3.Mention any three (or more) things that Parimal Ghose knew about Bepin Babu.
Answer:
Parimal Ghose knew that Bepin Babu always carries a bag of books with him, he had no children, he had lost his wife 10 years ago and his only brother died insane.

Bepin Choudhury’s Lapse of Memory Comprehension check (Page 65)

Question 1.Why did Bepin Babu worry about what Parimal Ghose had said ?
Answer:
He was worried as all those were intimate personal details which only a close person could know. Moreover, Bepin Babu did not know the man Parimal Ghose.

Question 2.How did he try to decide who was right-his memory or Parimal Ghose ?
Answer:
He decided to call Dinesh Mukerji who was there with him at that time at Ranchi.
He would decide what was right.

Question 3.Why did Bepin Babu hesitate to visit Mr. Mukerji? Why did he finally decide to phone him?
Answer:
He thought that if he visits Dinesh and confirms the trip, he would think him insane. Moreover, he could not take his ruthless sarcasm. In order to know about the truth, he finally decided to call him.

Question 4.What did Mr Mukerji say? Did it comfort Bepin Babu, or add to his worries?
Answer:
Dinesh Mukerji confirmed that he was there in Ranchi in ’58 with him. It makes
Bepin Babu more worried as he could not remember that episode.

Bepin Choudhury’s Lapse of Memory Comprehension check (Page 68)

Question 1.
Who was Chuni Lal ? What did he want from Bepin Babu ?
Answer:
Chuni Lal was Bepin Babu’s school friend. He wanted some help to get a job from his friend as he was jobless these days.

Question 2.
Why was Dr. Chanda puzzled ? What was unusual about Bepin Babu’s loss of memory ?
Answer:
Dr. Chanda had never experienced such type of a case about loss of memory. Bepin Babu had forgotten only one incident. It was unusual about his loss of memory.

Bepin Choudhury’s Lapse of Memory Comprehension check (Page 70)

Question 1.
Had Bepin Babu really lost his memory and forgotten all about a trip to Ranchi?
Answer:
No, Bepin Babu had not forgotten anything. Chuni Lal made his plan to teach him a lesson. Bepin Babu had never been to Ranchi.

Question 2.
Why do you think Chuni Lal did what he did? Chuni Lal says he has no money; what is it that he does have ?
Answer:
Bepin Babu had not helped Chuni Lal in getting a job in his hard times. Chunilal has no money but he possesses a good memory. He did all to teach him a lesson.

Bepin Choudhury’s Lapse of Memory Working With the Text (Page 70)

Question 1.
The author describes Bepin Babu as a serious and hardworking man. What evidence can you find in the story to support this ?
Answer:
Bepin Babu did not like mixing with people, had a few friends, lived alone and didn’t like spending time in idle conversation. He had been working for a big firm for the past more than 2 decades. Moreover, he had a reputation for being a conscientious worker.

Question 2.
Why did Bepin Babu change his mind about meeting Chuni Lal ? What was the result of this meeting ?
Answer:
Bepin Babu thought that Chuni Lal would remember something about his Ranchi trip in 1958. Chuni Lal confirmed his visit to Ranchi in ’58. Moreover he also informed that it was he who arranged for his ticket to Ranchi and got one of the fans repaired in his railway boggy.

Question 3.
Bepin Babu lost consciousness at Hudroo Falls. What do you think was the reason for this ?
Answer:
Bepin Babu went to Hudroo Falls. But he could not find any clue which could remind him that he had been there in Ranchi earlier. He thought he had no hope left and soon would lose everything. At that moment he got depressed and lost his mind. It overburdened him with the thought of loss of memory.

Question 4.
How do you think Bepin Babu reacted when he found out that Chunni Lal had tricked him ?
Answer:
I think that Bepin Babu must have regretted for not doing anything for his old friend Chuni Lal who was going through tough time.

CLASS-7 SUBJECT ENGLISH LESSON-4 "THE ASHES THAT MADE TREES BLOOM".

 EVENTS CONVENT HIGH SCHOOL

29/09/2021      CLASS-7      SESSION 2021-22
SUBJECT :ENGLISH

LESSON-4
THE ASHES THAT MADE TREES BLOOM

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Question 1.Why did the neighours kill the dog ?
Answer:The dog did not guide the neighbours to the treasure. So they killed the dog in extreme anger.

Question 2.Mark the right item
(i) The old farmer and his wife loved the dog
(a) because it helped them in their day-to-day work.
(b) as if it was their own baby.
(c) as they were kind to all living beings.

(ii) When the old couple became rich, they
(a) gave the dog better food.
(b) invited their greedy neighbours to a feast.
(c) lived comfortably and were generous towards their poor neighbours.

(iii) The greedy couple borrowed the mill and the mortar to make
(a) rice pastry and bean sauce.
(b) magic ash to win rewards.
(c) a pile of gold.
(i) The old farmer and his wife loved the dog as if it was their own baby.
(ii) When the old couple became rich, they lived comfortably and were generous towards their poor neighbours.
(iii) The greedy couple borrowed the mill and the mortar to make a pile of gold.

The Ashes that Made Trees Bloom Working with the text (Page-63)

Answer the following questions :

Question 1.The old farmer is a kind person. What evidence of his kindness do you find in the first two paragraphs.
Answer:
The old farmer is a kind person. He has a pet dog. Having no children, he loves it as if it were his own son. The old couple used to feed him with titbits of fish from their own
chopsticks.

Question 2.What did the dog do to lead the farmer to the hidden gold ?
Answer:
The dog tried to take him to some spot. He kept on running for some minutes. The old man followed his pet dog. At one place, the dog started scratching the earth. The old man dug the earth and found a pile of gold gleaming before him.

Question 3.(i) How did the spirit of the dog help the farmer first? ..
Answer:
The dog’s spirit asked his master to cut down the pine tree over his grave to make mortar for his rice pastry and a mill for bean sauce. The old couple made the dough ready for baking. As soon as he started pouring it, it turned into a heap of gold coins.

(ii) How did it help him next ?
Answer:
The dog’s spirit told his master how the wicked neighbours had burned the mill made from the pine tree. He suggested him to take the ash and sprinkle it on the withered trees. It would make them bloom.

Question 4.Why did the daimio reward the farmer but punish his neighbour for the same act ?
Answer:
The old farmer scattered a pinch of ashes over the tree. It burst into blossom. The daimio was pleased to see and ordered some reward of silk clothes, cake etc to the farmer. But on the other hand the greedy neighbour sprinkled handful of ashes, the wind blew it and straight went into the eyes of the daimios and his wife. He got angry. He ordered to punish the wicked man to death.

Question 4.Add im- or in- to each of the following words and use them in place of the italicised words in the sentences given below. patient proper possible sensitive competent:

(i) My friend lost his chemistry book. Now he doesn’t know……………. to do and …………to look for it.

(ii) There are so many toys in the shops. Neena can’t decide …………. one to buy.
(iii) You don’t know the way to my school. Ask the policeman ……………. to get there.
(iv) You should decide soon ………………… to start building your house.
(v) Do you know …………… to ride a bicycle ? I don’t remember ………….. and I learnt it.
(vi) “You should know ………………. to talk and ……………… to keep your mouth shut,” the teacher advised Anil.

Answer:
(i) what, where
(ii) which
(iii) how
(iv) when
(v) how, when, how.
(vi) where, when

CLASS-6 SUBJECT ENGLISH LESSON-4 AN INDIAN AMERICAN WOMAN IN SPACE.

  EVENTS CONVENT HIGH SCHOOL

29/09/2021      CLASS-6      SESSION 2021-22
SUBJECT :ENGLISH

LESSON-4
AN INDIAN AMERICAN WOMAN IN SPACE

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Working With the Text   (Page 50)

Answer the following questions.

1. Wkcie was Kalpana Chawla born? Why is she called an Indian-American? (3)

Ans: Kalpana Chawla was born at Kamal, in Haryana. She was born in India, but married an American and became a naturalised citizen. So she is called an Indian- American.

2. When and why did she go to the U.S? Who did she marry? (2, 3)

Ans: Kalpana went to the U.S. for higher studies in aeronautical engineering. There she married the flight instructor Harrison.

3. How did she become an astronaut? What gave her the idea that she could be an astronaut? (3)

Ans: Kalpana had already got a bachelor’s degree in aeronautical engineering before she went to the U.S. She earned her PhD in aerospace engineering. In 1994 she was selected by NASA for training as an astronaut. She was encouraged by the people around her.

4. What abilities must an astronaut have, according to the journalist? (6)

Ans: An astronaut needs to know a lot about biology and aeronautical engineering. He/ she must have a wide knowledge of science subjects.

5. Describe Kalpana Chawla’s first mission in space. (5)

Ans:  Kalpana’s first mission in the space shuttle, Columbia, was nearly 16 days long. She went around the earth 252 times. Among her colleagues were a Japanese and Ukranian astronauts. They performed so many experiments.

6. What does Kalpana Chawla say about pursuing a dream? Do you agree with her that success is possible? (7)

Ans:  Kalpana Chawla, a girl from a small town, touched the skies. In her message to college students of Chandigarh, from space, she said that it was always possible to realise one’s dream. One could certainly get success provided one had the vision and the courage.

Yes, I do agree with her on this point.                                                                      ‘

B. Read the newspaper report to find the following facts about the Columbia’s ill- fated voyage.

1. Date and place of lift off:16 January 2003.

2. Number of astronauts on board: Seven.

3. Number of days it stayed in space:About 16 days eighty experiments.

4. Number of experiments done by scientists:eighty experiments.

5. Date of return journey: .1 February 2003.

6. Height at which it lost contact:200,000 feet.

Working With Language   (Page 51)

A . Match the following

Ans: 1 .(f)           2. (e)                    3. (d)                      4. (g)

(b) 6. (a) 7. (c)

B. Use these phrases in sentences of your own, after finding out their meanings.

1.broke apart    2. streaked  over            3.  spread across

4.lifted off            5. blast off                       6.   went on

7.cheered along      8.on board                     9.   carry on

Ans:

1. broke apart – (parted, separated): The two wheels of my bicycle broke apart suddenly.

2.streaked over – (left a thin line or work): The jet plane streaked over our house high in the sky.

3.spread across – (became widely known or felt): The flu spread across the whole locality.

4.lifted off – (rose from the launching site): The helicopter lifted off the helipad with only two passengers.

5.blast off – (take off noisily): The spaceship blasted off at 2.30 a.m. sharp.

6.went on – (continued): The discussion went on the whole night.

7.cheered along – (encouraged): All the runners were cheered along by their fans.

8.on board – (inside the plane): The huge ship had nearly 500 passengers on board.

9.carry on – (continue doing something): She decided finally to cany on with her boss.

CLASS-9 SUBJECT SCIENCE CHAPTER-14 NATURAL RESOURCES

  EVENTS CONVENT HIGH SCHOOL

29/09/2021      CLASS-9      SESSION 2021-22
SUBJECT :SCIENCE

chapter-14
NATURAL RESOURCES

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1. Natural Resources
2. The Breath of Life: Air
3. Water: A Wonder Liquid
4. Mineral Riches in the Soil
5. Biogeochemical Cycles
6. Ozone Layer

Page: 193
Question 1. How is our atmosphere different from the atmosphere on Venus and Mars? 
Answer: Our atmosphere contains a mixture of many gases like nitrogen (78.08%), oxygen (20.95%), carbon dioxide (0.03%) and water vapor (in varying proportion). Whereas the atmosphere on Venus and Mars is mainly comprised of carbon dioxide. This carbon dioxide constitutes up to 95-97% of the atmosphere on Venus and Mars. It is supposed that due to this reason no life is known to exist on these planets.

Question 2. How does the atmosphere act as a bblanket?
Answer: It is a known fact that, air is a bad conductor of heat and our atmosphere contains mainly the air. Due to this reason, the atmosphere keeps the average temperature of the Earth fairly steady during the day and even during the course of the whole year. The atmosphere prevents the sudden increase in temperature during the daylight hours and during the night, it slows down the escape of heat into outer space.

Question 3. What causes winds ?
Answer: Winds are caused due to unequal heating of atmospheric air. This phenomena can be easily seen near coastal regions during the daytime. The air above the land gets heated faster and starts rising. As this air rises, a region Of low pressure is created and air over the sea moves into this area Of low pressure. The movement of air from one region to the other Creates winds. During the day, the direction of the wind would be from the sea to the land.

Question 4. How are clouds formed ? 
Answer:The water evaporates due to heating up Of water bodies and other biological activities. The air also heats and rises. On rising, it expands and cools to form tiny droplets. These droplets grow bigger, expand and form clouds. The collection Of dust and other suspended particles facilitate the process.

Page 194:
Question 1. Why do organisms need water ? 
Answer: Organisms need water due to the following
(i) All cellular processes take place in a water medium.
(ii) All the reactions that take place within our body and within the cells occur between substances that are dissolved in water.
(iii) Substances are also transported from one part of the body to the other in a dissolved form.
(iv) Water makes up about 70% of body weight Of all living organisms.
(v) It helps in the digestion of food and absorption of nutrients in the blood. Hence, organisms need to maintain the level of water within their bodies in order to stay alive. It helps in maintaining body temperature.
Question 2. What is the major source of freshwater in the city/town/village where you live ?
Answer: The major sources of freshwater in the city (town/ village is the underground water which is mostly taken out with the help of hand pumps or tube wells. The rivers flowing in the nearby areas, lakes and ponds also serve as the source of freshwater.

Question 3. DO you know any activity which may be polluting these water sources?
Answer: There are many activities which cause pollution Of water sources such as :
(i) Dumping of waste from factories, sewage from our towns and cities into rivers or lakes.
(ii) Discharging hot water from cooling towers into the water bodies affect the breeding capacity of aquatic organisms.

Page 196
Question 1. How is soil formed ? 
Answer: The formation of soil takes place in this way :
Over long periods of time, thousands and millions Of years, the rocks at or near the surface of the are broken down by various physical, chemical and some biological processes. The end product of this breaking down is the fine particles of soil. There are many other factors which play a vital role in the formation of soil. These factors are :
(i) The Sun : It causes heating of rocks which causes cracking and ultimately breaking up into smaller pieces.
(ii) Water: It breaks rocks both by freezing and fast flow.
(iii) Wind : It causes erosion of rocks similar to as done by fast flowing water. It also carries sand from one place to the other like water does.
(iv) Living organisms : Lichens and moss plants grow on the rock surface and cause rock surface to powder down and form a thin layer of soil. The roots of big trees sometimes go into cracks in the rocks and as the roots grow bigger, the crack is forced bigger.

Question 2.What is soil erosion ?
Answer: The removal of topsoil which is rich in humus and nutrients by flowing water or wind is known as soil erosion. If this process continues further then all soil may get washed away and the rocks underneath may get exposed. It may lead to the loss of all valuable resources because nothing grows as such on the rocks.

Question 3. What are the methods of preventing or reducing soil erosion ? 
Answer: The methods of preventing soil erosion are :
(i) Afforestation : Forests reduce erosion as the roots of trees hold the soil in place.
(ii) Shelter belts : Trees planted in lines or hedges around farmland reduce erosion by reducing the speed of the wind.
(iii) Contour ploughing : Farmers plough land so that furrows lie across the natural slope of the land. These furrows trap water and do not allow it to flow down carrying the topsoil.
(iv) Terrace (or step) farming : A terraced hillside is less likely to be eroded than a natural hillside. Here a series of steps formed by horizontal strips supported by walls, catch the descending water. It gives the water sufficient time to percolate into the soil and nourish the crop.
(v) Soil cover : Soil left bare after harvesting a crop is often covered with dried vegetation to prevent erosion. Steep slopes that cannot be ploughed are covered with grass or pasture crops.
(vi) Preventing overgrazing : As the grass has a tendency to bind soil molecules, so even a very little grass on a field prevents erosion of soil. But if the grass is overgrazed, it exposes the soil to erosion.

Page 201
Question 1. What are the different states in which water is found during the water cycle?
Answer: All three different states of water can be seen during the water cycle. These states are :
(i) Gaseous state (In the form Of water vapour which evaporates from the surface water). Liquid state (It is formed by the condensation of water vapour and can be Seen in the form of rain).
(ii) Solid state (It is formed by the freezing Of liquid droplets in the upper layer of atmosphere which can be seen in the form Of snow, hail Or sleet).

Question 2. Name two biologically important compounds that contain both oxygen and nitrogen
Answer: Proteins and nucleic acids (DNA and RNA).

Question 3. List any three human Which would lead to an increase in the carbon dioxide content of air.
Answer: Three human activities which would lead to an increase in the C02 content of air are :
(i) Respiration : It is the natural process Of release Of C02 by both plants and animals. But this release is neither dangerous nor it has any adverse effect on our environment.
(ii) Combustion of fuels : The various types of fuels are burnt to provide energy for various needs like heating, cooking, transportation and industrial fuels.
(iii) Deforestation : Trees help in the conversion Of C02 into organic compounds such as glucose, starch, etc., by the process of photosynthesis. When these trees are cut non-judiciously, then the level of C02 increases in our environment.

Question 1. Why is the atmosphere essential for life (SAII – 2011)
Answer: Atmosphere is essential for life because of the following masons :
(i) It keeps the average temperature of the earth fairly steady during the day and even during the course of the whole year.
(ii) It prevents the sudden increase in temperature during the daylight hours.
(iii) It contains all the important gases which are required for sustaining life on earth.
These gases are :
(a) Oxygen for respiration of living organisms and oxidation.
(b) Carbon dioxide for photosynthesis in plants and for making food.
(c) Nitrogen for providing inert atmosphere and making proteins.
(iv) The stratosphere region (16-23 km from the surface of Earth) of atmosphere contains a thick layer of ozone which filters the harmful UV radiation from Sun. If these radiations reach on the surface of Earth, then they may cause cancer in animals and are also harmful for plants.

Question 2. Why is water essential for life ? (SAII – 2011)
Answer: Water is considered essential for life because of the following reasons :
(i) All cellular processes take place in water medium.
(ii) All the reactions that take place within our body and within the cells occur between substances that are dissolved in water.
(iii) Substances are also transported from one part of the body to the other in a dissolved form.
(iv) Water makes up about 70% of body weight of all living organisms.
(v) It helps in the digestion of food and absorption Of nutrients in the blood. Hence, organisms need to maintain the level of water within their bodies in order to stay alive.
(vi) It helps in maintaining body temperature.

Question 3. How are living organisms dependent on the soil? Are organisms that live in water totally independent Of soil as a resource ?
Answer: Living organisms are dependent on the soil in the following ways :
(i) Soil provides a natural habitat for various different organisms (such as bacteria, fungi, algae) which help in improving the quality of the soil. Thus, they maintain the fertility of the soil.
(it) Number of insects, animals like rats, rabbits, etc., build their home in the soil.
(iii) Earthworms perform all their activities in the soil. They maintain fertility also as their excreta is rich in nitrogen.
(iv) Soil provides anchorage and nutrients to the plants for their growth and development.
Yes, all organisms that live in water are totally dependent on soil as a resoure :
The mineral nutrients are present in water in the dissolved form. But their recycling takes place only with the help Of decomposers which are present in the soil beds. Thus, all water bodies has soil beds which contain decomposers for the recycling of nutrients and to convert them into readily absorbable forms.

Question 4. You have seen weather reports on television and in newspapers. How do you think we are able to predict the weather?
Answer: Weather observatories collect information regarding the pattern of temperature, speed of wind, air pressure, ocean features and all other features which can affect the weather. This information is collected by remote sensing and weather forecasting satellites. The information collected is then sent to the meteorological departments which prepare a weather report which is displayed on the maps. This information is further transmitted through radio and television.