Photosynthesis and Respiration

1. Diagram of opened and closed stomata are given below:

2. During open stomata, guard cells are turgid as they absorb water. Conversely, when stomata are closed, guard cells are flaccid as the water is drawn out.

3. Stomata are found mainly on the lower surface of the leaves.

4. Three important processes of plants in which the stomata are involved are :

   1. Photosynthesis
   2. Transpiration
   3. Respiration

5. Stomata are open during the day and closed at night.

1. The given figure shows the process of Photosynthesis.
   Photosynthesis is the process by which green plants capture solar energy and use it to convert carbon dioxide and water into simple sugars and oxygen.

2. The balanced equation depicting Photosynthesis is given below:

Carbon dioxide + Water $\xrightarrow[\text{Sunlight}]{\text{Chlorophyll}}$ Glucose + Oxygen

3. The chloroplast is the organelle, and chlorophyll is the pigment, responsible for photosynthesis in plant cells. Chloroplasts contain chlorophyll, which captures light energy to convert carbon dioxide and water into glucose and oxygen.

4. Two by-products of Photosynthesis are Glucose (C₆ H₁₂ O₆) and Oxygen.

5. Photosynthesis is significant due to following reasons:

   1. Food for all — Plants prepare their own food by photosynthesis, and the plants in turn are eaten by the animals.
   2. Oxygen for respiration — All the free oxygen in the atmospheric air is the result of photosynthesis.

1. The aim of this experiment is to show that Oxygen is given out during Photosynthesis.

2. Hydrilla plants can be used for the experiment. Hydrilla plants belong to freshwater Aquatic habitat.

3. The gas formed is Oxygen. Oxygen is essential for the respiration of most living organisms.

4. To confirm the presence of Oxygen in the test tube, I will remove the test tube with the gas carefully, and insert a glowing matchstick inside it. If the matchstick starts burning, the gas is Oxygen.

5. The labelled diagram of this experiment in its 'initial stage' is given below:
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6CO₂ + 6H₂O $\xrightarrow[\text{Sunlight}]{\text{Chlorophyll}}$ C₆H₁₂O₆ + 6O₂

C₆H₁₂O₆ + 6O₂ $\xrightarrow{}$ 6CO₂ + 6H₂O + 38 ATP (Energy)

C₆H₁₂O₆ + 6O₂ $\xrightarrow{}$ 6CO₂ + 6H₂O + 38 ATP (Energy)

C₆H₁₂O₆ + 6O₂ $\xrightarrow{}$ 6CO₂ + 6H₂O + 38 ATP (Energy)

C₆H₁₂O₆ $\xrightarrow{}$ 2C₂H₅OH (Ethanol) + 2CO₂ + 2ATP (Energy)

Starch

Reason — Glucose is formed in leaves very rapidly during the photosynthesis and it cannot be transported to other parts with the same rapidity. So, several molecules of glucose join together to form insoluble starch for temporary storage.

Leaves

Reason — Stomata are present on the surface of leaves to facilitate exchange of gases between the leaf and the atmosphere.

Glucose

Reason — Fructose, Cellulose and lactose are polymers of glucose.

Photosynthesis

Reason — Photosynthesis is the process by which green plants capture solar energy and use it to convert carbon dioxide and water into simple sugars (glucose).

Chloroplast

Reason — Photosynthesis occurs in the mesophyll cells of the leaf. These cells contain numerous plastids called chloroplasts.

Glucose

Reason — Respiration is the process in which glucose is broken down to release energy.

Glucose

Reason — During photosynthesis, the plants first form simple soluble carbohydrates (glucose), and later, form complex insoluble carbohydrates (starch).

Ethanol

Reason — Anaerobic respiration in plants produces ethanol and carbon dioxide as end products.

Oxygen gas

Reason — A glowing matchstick starts burning in the presence of oxygen gas.

Iodine solution

Reason — The chemical used to identify the presence of starch is Iodine solution.

1. False
   Corrected Statement — Green plants prepare their food by using two raw materials; Carbon dioxide and water.

2. True

3. True

4. True

1. Taken in: Carbon dioxide
2. Given out: Oxygen

1. Guard cells
2. Adenosine Triphosphate (ATP)
3. Chlorophyll
4. Yeast
5. Transpiration

1. Photosynthesis : Day time :: Respiration : All day and night
2. Photo : light :: Synthesis : combining
3. Xylem : Water and minerals :: Phloem : Sucrose
4. Palisade cells : Barrel-shaped :: Guard cells : Bean-shaped
5. Photosynthesis : Chloroplast :: Respiration : All cells

1. Oxygen
2. Oxygen
3. Carbon dioxide
4. Alcohol
5. Starch

1. Autotrophic nutrition and Heterotrophic nutrition
2. Water, Carbon dioxide, Chlorophyll, Energy (from sunlight)
3. Palisade mesophyll and Spongy mesophyll
4. Xylem and Phloem
5. Aerobic respiration and Anaerobic respiration

1. Autotrophs — Green plants can prepare their own food, hence they are called autotrophs.

2. Photosynthesis — Photosynthesis is the process by which green plants capture solar energy and use it to convert carbon dioxide and water into simple sugars.

3. Respiration — Respiration is the process in which glucose is broken down to release energy.

4. Vascular system — All plants have a transport system called vascular system made of xylem, which carries water and minerals from roots to leaves, and phloem, which transports glucose from leaves to other parts of the plant.

5. Stomata — Stomata are tiny openings found mainly on the lower surface of the leaves that allow gases to pass in and out.

Leaves generally look green because of the presence of chlorophyll, a pigment that imparts green colour to leaves.

The source of energy for photosynthesis is Sunlight.

Plants respire all day and night as plants require a constant supply of energy for all the different processes that go on inside the cells of the plant body. Energy is required for the growth of the plant, for root cells to penetrate the soil and absorb water and minerals and so many other such activities. Thus, Respiration occurs continuously in plants, during both day and night.

The energy liberated during respiration is utilized for all the different processes that go on inside the cells of the plant body. Energy is required for the growth of the plant, for root cells to penetrate the soil and absorb water and minerals.

Chlorophyll is found in mesophyll cells of leaf, inside the plastids called chloroplast. Chlorophyll is very important as it absorbs the sunlight which provides energy for the process of photosynthesis. This energy is used to split water molecules (H₂O) into hydrogen ions (H⁺) and hydroxyl ions (OH^-). Oxygen from the hydroxyl ion is released into the air and hydrogen ions combine with carbon dioxide to form glucose.

Plants need oxygen for respiration. The source of oxygen is atmosphere.