I. Conceptual understanding

1. What is emulsification?

A: The digestion of fats by converting them into small globule like forms by the help of bile juice secreted from liver is emulsification.
 

2. What is photosynthesis?

A: It is the process by which green plants containing chlorophyll, produce food substances from carbon dioxide and water by using light as source of energy. The food produced consists of glucose and starch.
 

3. What is autotrophic nutrition?

A: The organism prepares food on its own without depending on any other organism. Food is prepared by the process of photosynthesis. Green plants and certain bacteria have autotrophic mode of nutrition.
 

4. Name the vitamins?

A: Vitamins are organic compounds which are needed in small quantities to sustain life.

Vitamins are two types. Water soluble vitamins and fat soluble vitamins.

Water soluble vitamins: B complex (Niacin-B6, Thiamine-B1) and vitamin C.

Fat soluble vitamins: vitamin A, D, E, K

       A- Retinol

       D- Calciferol

       E- Tocoferol

       K- Phylloquinone
 

5. What is chyme?

A: Chyme is soft slimy substance in which some proteins and carbohydrates have already broken down.
 

6. What is digestion?

A: The breaking down of complex food materials into simple substances so that the body with the help of enzymes can use them is called digestion.
 

7. What is ingestion?

A: The process of taking food into the body is called ingestion.
 

8. Where does photosynthesis take place in the plant?

A: Photosynthesis takes place in the chloroplasts of the cells.

     Light reactions occur in grand.

     Dark reactions occur in stroma region.

9. What are the products of light reaction?
A: The end products of light reaction are O₂, ATP and NADPH.
 

10. What are the products of dark reaction?
A: The product of dark reaction is glucose.
 

11. What is nutrition?
A: Procurement or intake of nutrients is nutrition.

II. Asking questions and making hypothesis

1. How do fungi and bacteria obtain their nourishment?
A: Bacteria and fungi are non-green plants. They cannot prepare their own food materials.
The feed on dead and decaying plant and animal bodies.
Thus, they are called saprophytes.
They break down the complex organic molecules present in dead and decaying matter and convert them into simpler substances outside the body.
Fungi and bacteria then absorb the substances that are converted into simpler substances as their food.
 

2. What is the function of the enzyme ptyalin or amylase?
A: Ptyalin or amylase is an enzyme that digests carbohydrates. It is produced in small intestine. Thus, the carbohydrates are digested in small intestine.

III. Experimentation and field investigation

1. Prove an experiment to show the presence of starch in leaves.
A:

     1. Take a leaf of a potted plant.
     2. Boil the leaf in methylated spirit over a water bath till it becomes pale-white due to the removal of chlorophyll . 
     3. Observe the leaf.
     4. Spread the leaf in a dish and add a few drops of tincture iodine/ betadine solution on it.
     5. Again observe the leaf.
     6. The presence of starch will be indicated by a blue-black colour.
 

2. How would you demonstrate that green plants release oxygen when exposed to light?
A:
                                    
 

Aim : To prove that oxygen is released during photosynthesis.
Apparatus : Hydrilla twigs, test tube, beaker with water
Experiment : Small pieces of Hydrilla twigs are placed in a funnel which kept in a beaker of water. A test tube is filled with water. Carefully it is inverted over the funnel. The entire set-up is kept in sunlight.
Observation : After sometime small gas bubbles come out of the leaves of hydrilla. These bubbles collect at the end of the test tube. When more gas is collected the test tube is taken out by closing its mouth with the thumb. When the gas is tested with a burning splinter it glows indicating that the gas released is oxygen.
Inference : By this experiment we can prove that oxygen is released during photosynthesis.

3. How do you prove that sunlight is necessary for photosynthesis?
A:

   

 Mohl's half leaf experiment

* Destarching a plant: To destarch a plant, we need to keep the plant in dark for about a week.
* Aim: To prove that Carbon dioxide is necessary for Photosynthesis
* Apparatus required: wide mouthed transparent bottle, destarched plant, potassium hydroxide pellets / potassium hydroxide solution, splitted cork.

* Procedure:
* Arrange the apparatus as shown in the figure.
* Take the wide mouthed transparent bottle.
* Put potassium hydroxide pellets / potassium hydroxide solution in the bottle. (Potassium hydroxide absorbs carbon dioxide)
* Insert splitted cork in the mouth of the bottle.
* Insert one of the leaves of destrached plant (through a split cork) into transparent bottle containing potassium hydroxide dioxide pellets/potassium hydroxide solution.
* Leave the plant in sunlight.
* After a few hours, test this leaf and any other leaf of this plant for starch.
* Observation: The leaf that was exposed to the atmospheric air becomes bluish black, and the one inside the flask containing potassium hydroxide that absorbs carbon dioxide in the bottle does not become blue-black.
* Inference: This shows that carbon dioxide is necessary for photosynthesis.

IV. Information skills and projects

1. What are the factors necessary for the process of photosynthesis? Write the details and your analysis on how they help in photosynthesis in a tabular form.
A:

Factor	Function
Sun Light	The radiation energy from the sun is used to activate electrons in the chlorophyll of the chloroplst in the leaves. These activated electrons' energy are used for 2 things. 1. To split a water molecule into H and O2. This process  is known as photolysis. The O2 is released as a product. The H is carried to the dark phase. 2. To form an ATP molecule out of ADP. This is known as phosphorilyzation.
Carbon dioxide	In higher concentrations, more carbon is incorporated into carbohydrate, therefore increasing the rate of photosynthesis in light-independent reactions.
Water and minerals	Chemicals and organic compounds which the plant-roots absorb from the soil are transported to the plant and used in photosynthesis.
Chlorophyll	Chlorophyll is vital for photosynthesis, which allows plants to absorb energy from light. Chlorophyll molecules are specifically arranged in and around photosystems that are embedded in the thylakoid membranes of chloroplasts.

2.  Write details about Dodder?
A:

Plant	Details
	Dodder or Cuscuta derives nourishment from host plant by producing haustoria into the host plant. It is parasitic on various agricultural and horticultural crops. Eg: potato

3. What are the food deficiency diseases?  

Answer:
Malnutrition is of three types 1. Calory malnutrition, 2. Protein malnutrition, 3. Protein calory malnutrition. Let us observe harmful effects of malnutrition in children.
1. Kwashiorkor disease: This is due to protein dificiency in diet. Body parts become swollen due to accumulation of water in the intercellular spaces. Very poor muscle development, swollen legs, fluffy face difficult to eat, diarea, dry skin are the symptoms of this disease.
2. Marasmus: This is due to deficiency of both proteins and calories.
Generally this disease occure when there is an immidiate second pregnancy or repeated child births. Lean and week, swelling limbs, less devoloped muscles, dry skin, diarea, etc., are the symptoms of this disease.
3. Obesity: This is due to over eating and excess of energy in take. It is a big health hazard. Obese children when grows of will be a target of many diseases like diabetes, cardio vascular, renal, gall bladder problems.
 

V. Communication through drawing, model making

1. Show photosynthesis through a diagram.
A:

 

2. Explain the structure of chloroplast with a neat labeled diagram?
A:
* It is a membrane bound organelle.
* It occurs mainly in the mesophyll cells of leaves.
* Typical chloroplast is disc shaped and is filled with colourless area called stroma.
* It is covered by two membranes.
* Stacks of thylakoid membranes are located in the stroma and are connected by stroma lamellae.
* It is green in colour due to the presence of a pigment called chlorophyll.
* The chlorophyll and other pigments of the chloroplasts are fat soluble and are located in the lipid part of the thylakoid membrane.
* It is organized to form the reaction centres called photosystem I and photosytem II.

 
 

3. See the diagram below. Describe the villi.
A: Villi are the finger-like projections formed from the walls of intestine.
They absorb the products of digestion.

 
 

4. See the picture below and write about it
A: Nutrition in Amoeba

 
 

VI. Appreciation and aesthetic sense, values

1. What is the function of stroma?
A: Stroma is a place for enzymatic reactions leading to the synthesis of glucose, which in turn join together to form starch.
 

2. Can you state some forms of nutrition in heterotrophic organisms?
A: The form of nutrition differs depending on the type and availability of food materials etc.
Some organisms break down food materials outside the body and then absorb it.
Eg: Bread mould, yeast, mushrooms etc.,
Some organisms take the whole material and break it down inside their bodies.
Eg: Animals
Some organisms derive nutrition from plants or animals without killing them.
Eg: Cuscuta, lice, leeches and tapeworms.
 

3. What are the important events that happen in chloroplasts?
A: Conversion of light energy to chemical energy
     Splitting of water molecule
    Reduction of carbon dioxide to carbohydrates.

VII. Application to daily life, concern to biodiversity

1. Why does vomiting occur?
A: Vomiting: it is the body’s method of ridding itself of un-wanted or harmful Substances from the stomach. The peristaltic movements of the stomach.
In addition, oesophagus reverses their normal direction and the food is expelled.
 

2. Explain about roughages?
A: Roughages are the fibres of either carbohydrates or proteins.
The intestine works properly due to roughages.
They help move the food quickly through the alimentary canal.
They keep a person healthy.
 

3. See the diagram below. Identify the diseases:
A:                  

 

 
4. What is malnutrition?
A: Eating of food that does not have one or more than one nutrients in required amount is known as malnutrition.
Types of malnutrition:
     1. Calorie malnutrition.
     2. Protein malnutrition.
     3. Protein calorie malnutrition.
 

5. What are peristaltic movements?
A: Food mixed with saliva passes through oesophagus by wave like movements called peristaltic movements to the stomach.
 

6. What is the difference between Autotrophic Nutrition and Heterotrophic Nutrition?
A:

Autotrophic Nutrition	Heterotrophic Nutrition
1. Autotrophs are the organisms capable of using light energy to synthesize chemical compounds.	1. Heterotrophs cannot synthesize their own food material.
2. They acquire nutrients like some minerals and water from the soil as well as some gases from the air.	2. Heterotrophs are the organisms that depend on autotrophs for food.
3. They are capable of producing large compounds like carbohydrates, proteins, lipids etc. from these very simple substances.	3. It may be holozoic, saprozoic, osmotrophic, parasitic, etc.
4. CO2 is taken and O2 is released.	4. O2 is taken and CO2 is released. In this process food is taken into body and undigested food is released outside of the body.
5. They depend directly on sunlight.	5. They depend indirectly on sunlight.
6. This type of nutrition takes place in plants.	6. This type of nutrition takes place in animals, bacteria etc.,