Students First Terminal Exams is approaching. Let us revise the text book questions of chapter Life processes.
Q1. Why is diffusion insufficient to meet the oxygen requirements of multicultural organisms like humans?
Ans . In unicellular organisms the entire surface of the organism is in contact with the environment. But in multicultural organisms all the cell may not be in direct contact with the surrounding environment. So diffusion is insufficient to meet the oxygen requirements of all the cells.
Q2. What criteria do we use to decide whether something is alive?
Ans. Living organisms must do breathing, movements, growth and development. Living creatures must keep repairing and maintaining their structures. They also produce their young ones.
Q3. What are outside raw materials used for by organisms?
Ans. Carbon based molecules like carbohydrates, proteins. and fats. Other molecules such as lipids, Vitamins and minerals are also essential.
Q4. What processes would you consider essential for maintaining life?
Ans. Digestion, Respiration Transportation and Excretion are essential for maintaining life.
Nutrition
Q1. What are the differences between autotrophic and heterotrophic nutrition?
Ans. Refer modes of nutrition given in the blog
Q2. Where do plants get each of the raw materials required for photosynthesis?
Ans
1. CO2 –from atmosphere through stomata
2. H2O – From soil through roots.
3. Other raw materials like nitrogen, phosphorus, iron and magnesium are taken up from the soil. Nitrogen is the most important material which is absorbed in the form of NO3-, NO2-.or is taken in the form of organic compounds which are prepared by bacteria from atmospheric nitrogen is used to form protein.
Sunday, July 20, 2008
Sunday, May 18, 2008
Nutrition in Plants
Autotrophic Nutrition: In this type of nutrition organisms makes its food itself by the process of photosynthesis. The organism takes CO2 and H2O from the environment and in the presence of chlorophyll and sunlight makes its food in the form of carbohydrates (Glucose). It is the source of energy to the plants. Excess glucose is stored in the form of starch.
CO2 + H2O Chlorophyll C6H12O6 + 6H2O+ 6O2
Sunlight
Steps of photosynthesis:
1. Chlorophyll absorbs light energy and converts it into chemical energy.
2. Splitting of water molecule and O2 is released.
3. Carbon dioxide is reduced to form carbohydrates.
Site of photosynthesis:
Transverse Section of leaf: In leaf two surfaces are present, upper epidermis and lower epidermis. In between the two epidermises mesophyll cells are present which are rich in chloroplast. Chlorophyll pigments are present in the chloroplast. Photosynthesis occurs in the chlorolopast of mesophyll cell of leaf.
Stomata are minute pores present in the leaf epidermis. The opening and closing of stomata is regulated by two guard cells. Nucleus and cloroplasts are also present in the guard cells.They are protected by surrounding epidermal cells.
Q Write the mechanism of opening and closing of stomata?
Ans. When the guard cells gain water they become turgid or swollen and stomata opens. When the guard cells lose water they shrink and stomata closes.
Q When plants do close their stomata?
Ans. When plants do not need CO2 for plants their stomata are closed. This also prevents the loss of water from the plant by transpiration.
Q,. How do plants get other materials for its growth and developments?
Plants need other minerals like N, S, Mg, Zn, Ca, P etc .Plants take these materials from the soil with the help of roots. The most important mineral is N. It is absorbed in the form of nitrate or nitrite and are used to form proteins.
CO2 + H2O Chlorophyll C6H12O6 + 6H2O+ 6O2
Sunlight
Steps of photosynthesis:
1. Chlorophyll absorbs light energy and converts it into chemical energy.
2. Splitting of water molecule and O2 is released.
3. Carbon dioxide is reduced to form carbohydrates.
Site of photosynthesis:
Transverse Section of leaf: In leaf two surfaces are present, upper epidermis and lower epidermis. In between the two epidermises mesophyll cells are present which are rich in chloroplast. Chlorophyll pigments are present in the chloroplast. Photosynthesis occurs in the chlorolopast of mesophyll cell of leaf.
Raw materials required for photosynthesis
Carbon dioxide: The epidermis of leaf has minute pores called stomata through which exchange of gases takes place between leaf and environment. CO2 from environment enters into the leaf cells through stomata.
Water: Water is absorbed by roots of the plant from the soil. Water is conducted through xylem up to the leaves.
Q How do desert plants, in which the stomata are closed at day time, carry out photosynthesis?
Ans: In desert plants the stomata are closed during day time. At night stomata opens CO2 diffuses into the leaf cells and is converted into an intermediate compound called malic acid. In the day time CO2 is released from malic acid and used to form food in the presence light.
Q. Explain the structure of stomata with the help of diagram.
Carbon dioxide: The epidermis of leaf has minute pores called stomata through which exchange of gases takes place between leaf and environment. CO2 from environment enters into the leaf cells through stomata.
Water: Water is absorbed by roots of the plant from the soil. Water is conducted through xylem up to the leaves.
Q How do desert plants, in which the stomata are closed at day time, carry out photosynthesis?
Ans: In desert plants the stomata are closed during day time. At night stomata opens CO2 diffuses into the leaf cells and is converted into an intermediate compound called malic acid. In the day time CO2 is released from malic acid and used to form food in the presence light.
Q. Explain the structure of stomata with the help of diagram.
Stomata are minute pores present in the leaf epidermis. The opening and closing of stomata is regulated by two guard cells. Nucleus and cloroplasts are also present in the guard cells.They are protected by surrounding epidermal cells.Q Write the mechanism of opening and closing of stomata?
Ans. When the guard cells gain water they become turgid or swollen and stomata opens. When the guard cells lose water they shrink and stomata closes.
Q When plants do close their stomata?
Ans. When plants do not need CO2 for plants their stomata are closed. This also prevents the loss of water from the plant by transpiration.
Q,. How do plants get other materials for its growth and developments?
Plants need other minerals like N, S, Mg, Zn, Ca, P etc .Plants take these materials from the soil with the help of roots. The most important mineral is N. It is absorbed in the form of nitrate or nitrite and are used to form proteins.
Friday, May 16, 2008
Nuttrition
It is the process in which organisms obtains and utilize its food. It includes ingestion, digestion, absorption of digested food and egestion.
Functions of food
1. It provides energy to do work.
2. It provides raw materials necessary for growth, development, reproduction and for the synthesis of variety of substances in the body.
3. It helps in repairing damaged cells and tissues.
Modes of Nutrition:
1. Autotrophic Nutrition: In this type of nutrition organisms makes its food itself by the process of photosynthesis. The organism takes CO2 and H2O from the environment and in the presence of chlorophyll and sunlight makes its food in the form of carbohydrates (Glucose). It is the source of energy to the plants. Excess glucose is stored in the form of starch.
CO2 +H2O Chlorophyll C6H12O6 +6O2
Sunlight
2. Saprophytic Nutrition: The organisms feed on dead and decaying matter like fungi, molds, yeast, and mushroom. The enzymes are released outside the body from the dead organic matter. Enzymes break the complex organic matter into simple substances. Soluble forms of this substance are then absorbed by the organisms.
rtf
3. Parasitic Nutrition: When an organism takes its food from other living organisms without killing them. The organism is called parasite and from whom the food is taken is called host. The parasites live on or inside the body of their host e.g. round worm, tapeworm, ticks cuscuta etc.
Functions of food
1. It provides energy to do work.
2. It provides raw materials necessary for growth, development, reproduction and for the synthesis of variety of substances in the body.
3. It helps in repairing damaged cells and tissues.
Modes of Nutrition:
1. Autotrophic Nutrition: In this type of nutrition organisms makes its food itself by the process of photosynthesis. The organism takes CO2 and H2O from the environment and in the presence of chlorophyll and sunlight makes its food in the form of carbohydrates (Glucose). It is the source of energy to the plants. Excess glucose is stored in the form of starch.
CO2 +H2O Chlorophyll C6H12O6 +6O2
Sunlight
Heterotrophic Nutrition: It is the type Nutrition in which organisms can not make its own food directly and indirectly.
Types of heterotrophic nutrition:
1. Holozoic Nutrition: The animals engulf the food material which is a complex molecule and is broken down into simpler substances. It involves ingestion, digestion, absorption of digested food and egestion e.g. animals
2. Saprophytic Nutrition: The organisms feed on dead and decaying matter like fungi, molds, yeast, and mushroom. The enzymes are released outside the body from the dead organic matter. Enzymes break the complex organic matter into simple substances. Soluble forms of this substance are then absorbed by the organisms.
rtf
3. Parasitic Nutrition: When an organism takes its food from other living organisms without killing them. The organism is called parasite and from whom the food is taken is called host. The parasites live on or inside the body of their host e.g. round worm, tapeworm, ticks cuscuta etc.
Cuscuta
Friday, February 8, 2008
ASSIGNMENT
Management of Natural Resources
1. Define the term natural resource.
2. What is meant by the term ‘sustainable development?
3. What are the three R’s to save the environment?
4. Name the project launched to clean Ganga. ? Explain with one example each.
5. What does presence of coli form in water indicate?
6. What is the pH of neutral sample of water?
7. What do you mean by recycle?
8. What do you understand by re use of material?
9. What do you mean by re use? Explain it with example.
10.Name the 4 main of stake holders in the management of forest resources?
11. What is silvi culture? What are its advantages
12.Name the major industries which are based on forest produces?
13.Why should we conserve forest & wild life?
14.What changes would you suggest in your home or in school in order to be environment friendly?
15.How participation of the local people lead to efficient management of forest.
16.Give an account of the 4 stake holders of forest.
17.1. What are the main reasons why human beings are over exploiting the forest?
2.What are the effects of deforestation?
3.Name the different measures taken up for the conversation of forest.
18.Write a short note on Chipko Andolan
19.What is Amrita Devi Bishnoi National Award?
20.Name the major programmes started to replenish forest.
21.Name any 5 sources of water?
22.State the advantages of constructing dams across the river?
23.Explain why despite o good rains, we are not able to meet the demand for water or all the people in our country?
24.What is Ganga Action Plan? When was it implemented?
25.Name the irrigation project in M.P. that resulted in water logging?
26.Describe any three problems associated with construction of dams?
27.What is Narmada Bachao Andolan?
28.Name 2 factors which can be used to find whether river water has been contaminated?
29.What do you mean by rain water harvesting?
30.Name some of the common methods used or rain water harvesting by the rural people?
31.What are the various advantages of the water stored in the ground?
32.Describe the “ Khadin” System of rain water harvesting practiced in Rajasthan?
33.What are Fossils fuels? How are coal and petroleum formed? Why are they should be used judiciously?
34.Write the 4 steps which can be taken to conserve fossils fuel?
35.How do coal and petroleum based fuels affect us and our environment?
1. Define the term natural resource.
2. What is meant by the term ‘sustainable development?
3. What are the three R’s to save the environment?
4. Name the project launched to clean Ganga. ? Explain with one example each.
5. What does presence of coli form in water indicate?
6. What is the pH of neutral sample of water?
7. What do you mean by recycle?
8. What do you understand by re use of material?
9. What do you mean by re use? Explain it with example.
10.Name the 4 main of stake holders in the management of forest resources?
11. What is silvi culture? What are its advantages
12.Name the major industries which are based on forest produces?
13.Why should we conserve forest & wild life?
14.What changes would you suggest in your home or in school in order to be environment friendly?
15.How participation of the local people lead to efficient management of forest.
16.Give an account of the 4 stake holders of forest.
17.1. What are the main reasons why human beings are over exploiting the forest?
2.What are the effects of deforestation?
3.Name the different measures taken up for the conversation of forest.
18.Write a short note on Chipko Andolan
19.What is Amrita Devi Bishnoi National Award?
20.Name the major programmes started to replenish forest.
21.Name any 5 sources of water?
22.State the advantages of constructing dams across the river?
23.Explain why despite o good rains, we are not able to meet the demand for water or all the people in our country?
24.What is Ganga Action Plan? When was it implemented?
25.Name the irrigation project in M.P. that resulted in water logging?
26.Describe any three problems associated with construction of dams?
27.What is Narmada Bachao Andolan?
28.Name 2 factors which can be used to find whether river water has been contaminated?
29.What do you mean by rain water harvesting?
30.Name some of the common methods used or rain water harvesting by the rural people?
31.What are the various advantages of the water stored in the ground?
32.Describe the “ Khadin” System of rain water harvesting practiced in Rajasthan?
33.What are Fossils fuels? How are coal and petroleum formed? Why are they should be used judiciously?
34.Write the 4 steps which can be taken to conserve fossils fuel?
35.How do coal and petroleum based fuels affect us and our environment?
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