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1. All living organisms constantly need energy to be alive.

2. They get energy from the food they eat.

3. The food directly or indirectly comes from the green plants through photosynthesis.

4. Hence photosynthesis can be considered as the basic energy source for most of living world.

(D) all the above

B) small intestine

The ultimate source of energy is the Sun

The mesophyll cells of leaf containing palisade and spongy tissue photosynthesis takesplace

B) the absence of enzymes that act on them

Answer is (B) Grana

Answer is (A) Stomata

B) end products of light reactions

C) they occur in grana of chloroplast

CO₂ present in the atmosphere enters through stomata into the cells of leaf by diffusion.

1. The entire series of reactions involved in the conversion of CO₂ to glucose were identified by Melvin Calvin. 

2. The dark reactions are also called as Calvin Cycle.

Phosphoglyceric acid or PGA is the first stableproduct formed in dark reaction or photosynthesis.

1. The new leaves which look dark red in colour contain coloured chromoplasts. 

2. As the leaf grows the chromoplasts turns to chloroplasts and the leaf appears green in colour.

i) To prove that CO₂ is necessary for photosynthesis. 

ii) The leaf part kept in the bottle does not show colour change in iodine test, whereas the leaf exposed to air turns bluish-black in the iodine test

iii) To remove starch from leaves (destarching).

In the dark reaction, the hydrogen of the NADPH is used to combine with CO₂ by utilizing ATP energy and ultimately produce glucose.

1. Conversion of light energy to chemical energy. 

2. Splitting of water molecule. 

3. Reduction of carbon dioxide to carbohydrates.

The end products of fats are fatty acids and glycerol.

Answer is (C) A & B

(C) both A and B

C) O₂ , ATP, NADPH 

C) light, CO₂ , water and chlorophyll

(B) CO₂ is essential for photosynthesis. 

Given leaf is tested through Mohl’s experiment. The dark coloured part shows the presence of Starch.

Correct answer is (d) maltose

D) Pelletier and Caventou

(C) Von Sachs

Answer is (D) All

(C) Vitamin – A

Pellagra is caused due to the deficiency of Niacin

(C) Cyanocobalamin

Answer is (A) Biotin

(A) Ascorbic acid

The children appear with swollen legs, hands and other body parts. They have dry skin and suffering from diarrhoea. 

The reason for it is malnutrition and they are suffering from Kwashiorkor and Marasmus diseases.

 They are advised to take proteins and calorie rich foods like liver, meat, eggs, milk, fruits, cereals and leafy vegetables.

Priestly hypothesized that plants restore to the air whatever breathing animals and burning candles remove.

Priestly might have used convex lens through which beam of sun rays can light the candle from outside or he might have used long burning stick, to light the candle by lifting the jar partially.

Priestly’s experiment confirmed that gaseous exchange was going on and plants were giving out a gas that supported burning and was essential for the survival of animals. By combustion process candle releases carbondioxide. By respiration process rat also releases carbondioxide. During photosynthesis process mint plant uses this carbondioxide and releases oxygen. This oxygen will be used by rat to stay alive and for the candle to burn. So there is a relationship between respiration and photosynthesis by candle, rat and mint plant.

1. The plant is kept in the dark for nearly a week to remove the starch from the leaves. 

2. Then only we can understand that the starch is formed in the leaves or not after the experiment when the plant is kept in the sunlight.

C) To absorb CO₂ in bottle

Carbon dioxide, water, chlorophyll and sunlight are the essential factors required for photosynthesis.

(D) Light, Water, Chlorophyll, CO₂

C) Intensity of light

Note on light dependent reactions: 

1. Light dependent reactions are also called as photochemical phase. 

2. The light dependent reaction takes place in chlorophyll containing thylakoids called grana of chloroplasts. 

3. Several steps occur in the light dependent reaction. 

4. Step – 1: The chlorophyll on exposure to light energy becomes activated by absorbing photons.

5. Step – II: The energy is used in splitting the water molecule into two component ions named hydrogen (H⁺), hydroxyl ion (OH^-). This reaction is known as photolysis. 

6. Step – III: OH^- ions through a series of steps produce water (H₂O) and O₂. 

7. The end products of light reaction are ATP, NADPH and O₂. 

Note on dark reaction or light independent reaction: 

1. In light independent phase the hydrogen of the NADPH is used to combine it with CO₂, by utilizing ATP energy and to produce glucose. 

2. This synthesis occurs in a number of steps using certain special intermediate compounds (mainly RUBP – Ribulose hi phosphate) and enzymes. Finally glucose is converted to starch. 

3. All these reactions occur in the stroma region of the chloroplast.

The light reaction takes place in chlorophyll-containing thylakoids called grana of chloroplasts.

Carbohydrates, proteins and lipids are produced from simple inorganic substances like water and CO₂ .

The events that occur in chloroplasts during photosynthesis are

1. Conversion of light energy to chemical energy.
2. Splitting of the water molecule and
3. Reduction of carbon dioxide to carbohydrates.

(C) 250 to 400