Photosynthesis

Q.

Experiment to show that sunlight is essential for photosynthesis.

Q.

What is holozoic nutrition?

Q.

State any four differences between photosynthesis and respiration.

Q.

Why sleeping under a tree at night is not advisable?

1. At night, since photosynthesis does not occur, oxygen is not being produced by the trees. In addition to this, the trees continue respiring thereby causing the amount of carbon dioxide to be increased and the amount of oxygen to be reduced.

2. At night, trees produce a lot of water vapour which causes the area below the tree to be very humid. This will mean that there is lesser oxygen available in the area for breathing.

3. At night, since the stomata on a leaf are closed, there is no gas exchange taking place. Therefore, there is neither oxygen nor carbon dioxide present around a tree at night.

4. At night, trees give out some toxic gases such as sulphur dioxide. This can be harmful to humans as well as other life forms.

Q. What is translocation?
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Q.

Explain the process of synthesis of food in green plants.

Q.

Explain excretion in plants with full details

Q.

What is the light-harvesting complex?

Q.

Leaves are called the food factories of plants .

True

False

Q.

Two potted green plants of the same kind were taken to perform an experiment. One of them was kept in a dark room, while the other one was kept in sunlight for 3–4 days. A leaf from each of the plant was taken to perform the iodine test. Which of the leaves turned blue-black in colour and why? [5 MARKS]

Q.

Apart from carbon dioxide and water, name four other raw materials which are needed by the plants.

Q. The image given below shows the cross section of a leaf with labels (i) to (iv). Identify the option that correctly identifies the structure and corresponding function.

1. (i) Midrib: Attracts insects for pollination
2. (ii) Lower epidermis: Protects from mechanical damage
3. (iii) Waxy cuticle: Prevents loss of water
4. (iv) Chloroplasts: A cell organelle that conducts photosynthesis

Q.

Name the process by which plants make food.

Q.

Why is it necessary to place a plant in the dark before starting an experiment on photosynthesis? Explain.

Q.

Describe the events in the process of photosynthesis and give the chemical equation.

Q.

Which one chemical reaction occurs during photosynthesis ?

(a) Carbon dioxide is reduced and water is oxidised.

(b) Water is reduced and carbon dioxide is oxidised.

(c) Both carbon dioxide and water are oxidised.

(d) Both carbon dioxide and water are reduced.

Q. To show that oxygen is produced during photosynthesis, aquatic plants like Hydrilla is used.

1. True
2. False

Q.

Name the factors affecting photosynthesis.

Q. What is compensation point ?

Q.

What happens to the glucose formed during photosynthesis?

Q.

Why is redox potential important?

Q.

What is photo-oxidation?

Q.

Which light range is the least effective for the process of photosynthesis?

Q.

Name the organelle of plant cells in which photosynthesis occurs.

Q. In what form glucose is stored in animals and plants

Q.

Name two inorganic substances which are used by autotrophs to make food.

Q. Name the following :
(a) The process in plants which converts light energy into chemical energy.

Q.

(a) How does carbon dioxide from the air enter the leaves of a plant to be used in photosynthesis ?
(b) How does water from the soil reach the leaves of a plant to be used in photosynthesis ?

Q.

How would you demonstrate that green plants release oxygen when exposed to light ?

Q.

Which substance is used to remove chlorophyll from a green leaf during photosynthesis experiments?