10 Most FAQ’s of Nutrition Chapter in Class 10th Biology (TS/AP)

Find the top 10 FAQs for the Nutrition Chapter in Class 10th Biology (TS/AP) here. Our page simplifies complex concepts, making them easy to understand for students. It’s perfect for quick study, exam prep, and grasping key points in the curriculum.

8 Marks

LAQ-1: Write the experimental procedure and observation to prove that “Oxygen is released in photosynthesis by green plants”.

Introduction

• Aim: To demonstrate how green plants, specifically Hydrilla, produce oxygen during photosynthesis in the experiment.
• Purpose: The experiment aims to illustrate the process by which green plants, particularly the common aquatic plant Hydrilla, produce oxygen during photosynthesis.

Materials Required

1. Two beakers
2. Water
3. Hydrilla plant
4. Two Funnels
5. Two Test Tubes

Assembling the Setup:

1. Beaker with Water: Fill a beaker with water.
2. Submerge Hydrilla Plant: Put the Hydrilla plant into the water in the beaker.
3. Invert Funnel: Turn a funnel upside down and cover the plant with it.
4. Water-Filled Test Tube: Place a test tube filled with water over the stem of the funnel, sealing the setup.
5. Observation: This setup is important for watching how the Hydrilla plant does photosynthesis.

Setup Placement

• Positioning for Experiment: Position the setup under direct sunlight because sunlight is necessary for the Hydrilla plant to perform photosynthesis.
• Control Setup (Shade Setup): Create a Control Setup (Shade Setup) by covering a second setup with black paper and placing it in a shaded area. This control setup is crucial to demonstrate the absence of photosynthesis in the absence of light, serving as a comparison point for the experiment.

Observation

• Sunlight Setup: In the experiment, the observation of small bubbles forming in the test tube indicates gas production. To further confirm the nature of this gas, one can introduce a glowing matchstick near the mouth of the test tube. If the matchstick rekindles, it conclusively confirms the presence of oxygen.
• Shade Setup: No bubble formation will be observed, indicating no oxygen production due to the absence of sunlight.

Precautions

• Gas Leakage Prevention: When conducting the experiment, it’s crucial to ensure there’s no gas leakage while handling the test tube, maintaining safety and accuracy in the procedure.
• Securing the Test Tube: Additionally, when transferring the gas, it is important to secure the mouth of the test tube with your thumb to prevent the gas from escaping, thereby preserving the integrity of the experiment.

Summary

The experiment’s findings visually confirm that green plants release oxygen during photosynthesis, with the Hydrilla in the sunlight setup producing bubbles indicative of oxygen, while the shaded setup exhibits no such activity.

---

Introduction

Photosynthesis is a process used by plants to convert light energy into chemical energy. The light reaction, also known as the light-dependent reaction, is the first phase of photosynthesis. It occurs in the thylakoid membranes of chloroplasts in plant cells. This phase utilizes light energy, captured by chlorophyll and other pigments within the photosystems, to drive the subsequent steps.

Step 1: Absorption of Light Energy

Chlorophyll and other pigments, embedded in the photosystems of the thylakoid membranes, absorb photons of light. The absorbed light energy excites electrons in the chlorophyll molecules to higher energy levels.

Step 2: Photolysis (Hill’s Reaction)

Water molecules (H₂O) are split into oxygen (O₂), protons (H+), and electrons (e^-) in this stage. This process, known as photolysis, releases oxygen as a byproduct. The electrons released from water molecules are used to replace the excited electrons in the chlorophyll.

Step 3: Formation of ATP (Adenosine Triphosphate)

The light energy, captured and transferred by the electron transport chain, drives the movement of protons across the thylakoid membrane, creating a proton gradient. This gradient is used to phosphorylate ADP into ATP, a high-energy molecule essential for various cellular processes.

Step 4: Formation of NADPH (Nicotinamide Adenine Dinucleotide Phosphate)

NADP+ is reduced to NADPH by accepting electrons from the electron transport chain. NADPH, carrying high-energy electrons, is crucial for the Calvin cycle, the subsequent phase of photosynthesis.

Summary

The light reaction, occurring in the grana of chloroplasts, is a critical first step in photosynthesis. It involves the absorption of light energy by chlorophyll, leading to the photolysis of water molecules and the release of oxygen. This reaction converts light energy into chemical energy in the form of ATP and NADPH, which are vital for the Calvin cycle, where carbon dioxide is fixed and converted into glucose. The light reaction thus enables plants to harness light energy to produce food.

---

LAQ-3 : What process do you following the laboratory to study the presence of starch in leaves? (OR) Explain the procedure and precautions to prove “the presence of starch in leaves” experiment.

Introduction

This experiment aims to demonstrate the presence of starch in leaves, a carbohydrate produced during photosynthesis. By detecting starch, we can understand and visually confirm the process of photosynthesis in green plants.

Materials Required:

1. A soft and thin leaf from a plant, preferably one well exposed to sunlight
2. Test tube
3. Boiling water
4. Ethanol (commonly referred to as methylated spirit)
5. Water bath
6. Brush
7. Iodine or betadine solution
8. Petri dish

Procedure

1. Choose a Leaf: Select a leaf that has been well exposed to sunlight, as this increases the likelihood of it having undergone photosynthesis.
2. Blanch the Leaf: Blanch the leaf by boiling it in a test tube with water. This step kills the leaf, stops its internal chemical processes, and makes the leaf more permeable.
3. Transfer to Ethanol: After blanching, transfer the leaf using a brush to another test tube containing ethanol. The purpose here is to remove the chlorophyll, making the leaf pale.
4. Boil in Water Bath: Boil this test tube in a water bath. Handle the hot liquids and ethanol with care, as they are both flammable and hot.
5. Rinse and Place: After boiling, briefly rinse the leaf in warm water to soften it, then place it on a petri dish.
6. Iodine Solution: Finally, drop a few drops of iodine solution onto the leaf.

Observation

A bluish-black coloration on the leaf after applying iodine indicates the presence of starch. If no starch is present, the leaf will not change color.

Inference

The development of a bluish-black color on the leaf confirms the presence of starch, which is a product of photosynthesis. The iodine reacts with starch to produce this color.

Precautions

Handle hot liquids and ethanol with care. Ensure the leaf is fully immersed in ethanol, and transfer it gently to avoid damage. Be aware that ethanol is flammable, so perform the experiment away from open flames.

Summary

In this experiment, a leaf is blanched, decolorized, and then tested for starch with iodine solution. The appearance of a bluish-black color confirms the presence of starch, indicating that photosynthesis has occurred. This practical demonstration highlights the synthesis of starch during photosynthesis in green plants. Safety and accuracy are essential for the success of the experiment.

---

LAQ-4 : Mention different modes of nutrition. Explain the mode of nutrition in cuscuta.

Introduction

In nature, living organisms exhibit various modes of nutrition based on how they obtain and utilize their food. These can be broadly classified into two main types: autotrophic nutrition and heterotrophic nutrition. Autotrophs, like green plants and some bacteria, produce their own food, whereas heterotrophs, such as fungi, animals, and many bacteria, rely on consuming organic matter from other sources. An intriguing example of heterotrophic nutrition is seen in Cuscuta, commonly known as dodder, which is a parasitic plant.

Different Modes of Nutrition

1. Autotrophic Nutrition: Observed in green plants and some bacteria, these organisms synthesize their own food using sunlight, water, and carbon dioxide through photosynthesis.
2. Heterotrophic Nutrition: Found in organisms like fungi, animals, and many bacteria, these cannot produce their own food and depend on other organic matter. Heterotrophs can be further classified as saprophytes, parasites, or holozoic organisms, depending on their specific feeding habits.

Mode of Nutrition in Cuscuta – Parasitic Nutrition

1. Cuscuta – Unique Parasite: Cuscuta or dodder is a unique example of heterotrophic nutrition due to its parasitic lifestyle. This leafless plant lacks chlorophyll, the essential pigment for photosynthesis.
2. Lack of Chlorophyll: Since it lacks chlorophyll, Cuscuta is unable to conduct photosynthesis and doesn’t produce its own food.
3. Haustoria for Nutrient Absorption: Cuscuta has developed specialized structures called haustoria, which are root-like and penetrate the tissues of a host plant to access its vascular system.
4. Parasitic Lifestyle: Being a parasite, Cuscuta relies entirely on its host plants. It draws water, minerals, and nutrients, including sugars and carbohydrates, from its host.
5. Growth and Attachment: Initially growing from a seed, dodder develops a temporary anchoring root, then it elongates into a slender stem, spiraling around and attaching itself to a host plant.
6. Nutrient Extraction: As it twines around the host, dodder forms haustoria to penetrate the host’s vascular tissues, extracting essential nutrients from the xylem and phloem.

Summary

Cuscuta, or dodder, showcases parasitic nutrition, a form of heterotrophic nutrition. Without chlorophyll for photosynthesis, it relies on attaching to host plants and extracting nutrients through haustoria. This adaptation allows Cuscuta to survive and grow as a parasite, highlighting the diversity of nutritional strategies in plants. However, its parasitic nature often adversely affects the host plants.

---

LAQ-5 : How can you prove that sunlight is necessary for photosynthesis?

Introduction

Photosynthesis is a critical process in green plants, enabling them to synthesize food from sunlight, water, and carbon dioxide. Sunlight plays a pivotal role in this process, providing the energy necessary for transforming these raw materials into glucose and oxygen. Chlorophyll, the green pigment in plants, aids in absorbing sunlight. To illustrate the importance of sunlight in photosynthesis, a simple experiment can be carried out.

Aim: To demonstrate that sunlight is essential for the photosynthesis process in plants.

Materials Required

1. A de-starched plant (a plant that has been kept in the dark for 24 hours to remove any stored starch)
2. Black paper
3. Iodine solution

Procedure

1. Select a leaf from the de-starched plant.
2. Cut a piece of black paper in a specific design, such as an S shape.
3. Cover the chosen leaf with the black paper, ensuring part of it is shielded from sunlight.
4. Place the plant in bright sunlight for about 6 hours.
5. After exposure, remove the black paper and test the leaf for starch presence using iodine solution.

Observation

Examine the leaf, focusing on the portion covered by black paper (the shaded area) and the area exposed to sunlight (the S-shaped area). Before testing, the leaf should be boiled in alcohol to remove chlorophyll, making the starch test more visible.

Result and Inference

The area of the leaf exposed to sunlight (the S-shaped area) will show a bluish-black coloration upon testing with iodine, indicating the presence of starch. Conversely, the shaded area will show no such coloration, implying no starch formation.

Summary

This experiment clearly demonstrates that sunlight is crucial for photosynthesis in plants. Starch formation, a key product of photosynthesis, occurs only in the leaf areas exposed to sunlight. The absence of starch in the shaded area confirms sunlight’s essential role in enabling plants to convert light energy into chemical energy, thus producing food necessary for their growth and survival.

---

LAQ-6 : List out the materials required and the procedure to be followed to prove that “Carbon dioxide is essential for photosynthesis”.

Introduction

Photosynthesis is a vital process where plants convert carbon dioxide and water into glucose and oxygen, using sunlight as an energy source. An experiment using a de-starched plant and potassium hydroxide (KOH) solution is conducted to demonstrate the importance of carbon dioxide in this process.

Materials Required

1. De-starched plant: A healthy plant kept in darkness for at least 3 days to eliminate stored starch.
2. Potassium hydroxide (KOH) pellets or solution: To absorb carbon dioxide. If using a solution, specify the concentration.
3. Wide-mouthed transparent bottle.
4. Split cork: To seal the bottle opening.
5. Iodine solution: For testing the presence of starch.

Procedure

1. Fill the Bottle: Fill a wide-mouthed transparent bottle with KOH pellets or solution.
2. Seal the Bottle: Seal the bottle opening with a split cork.
3. Insert the Leaf: Partially insert a leaf from the de-starched plant into the bottle, making sure it does not touch the KOH solution.
4. Sunlight Exposure: Place the setup in a sunny location and leave it undisturbed for a few hours.
5. Remove the Leaves: After this period, remove the leaf from the bottle. Also, take another leaf from the same de-starched plant.
6. Boil the Leaves: Boil both leaves in water and then in alcohol to remove chlorophyll, making them suitable for the starch test.
7. Starch Test: Place each leaf in separate petri dishes and add iodine solution to test for the presence of starch.

Observation

In the experiment, the leaf that was inside the bottle and exposed to the KOH solution will remain colorless, signifying an absence of starch. In contrast, the other leaf, which was exposed to atmospheric air and sunlight, will turn bluish-black, a clear indication of the presence of starch. This contrast demonstrates the differing effects of environmental conditions on the presence of starch in plant leaves.

Summary

This experiment demonstrates that the leaf exposed to the KOH solution, which absorbed the carbon dioxide, did not produce starch. Conversely, the leaf exposed to atmospheric air and sunlight did produce starch, confirming that carbon dioxide is a crucial component of photosynthesis. This experiment underscores the essential role of carbon dioxide in enabling plants to synthesize glucose, their primary energy source and building block for growth and development.

---

LAQ-7 : Read the table and answer the following questions.
1. Name the anti-sterility vitamin from the above table.
2. Which vitamin deficiency causes the gums bleeding?
3. Name the fat soluble vitamins from the above.
4. Name the symptoms that appear due to deficiency of vitamin K.

Tocopherol (Vitamin E)

Tocopherol, commonly referred to as Vitamin E, is widely recognized for its role as the anti-sterility vitamin. Its importance lies in its crucial contribution to reproductive health and its function as an antioxidant, which helps in protecting body cells from damage. This dual role underscores Vitamin E’s significance in maintaining overall health and wellbeing.

Ascorbic Acid (Vitamin C)

A deficiency of ascorbic acid, known as Vitamin C, primarily leads to gums bleeding, a notable symptom of its lack. The role of Vitamin C is vital as it is essential for the repair of tissues and the enzymatic production of certain neurotransmitters. Additionally, it plays a significant role in immune system function and enhances the absorption of iron from food, highlighting its multifaceted importance in maintaining health.

Fat-Soluble Vitamins

The fat-soluble vitamins include Retinol (Vitamin A), Cholecalciferol (Vitamin D), Tocopherol (Vitamin E), and Phylloquinone (Vitamin K). These vitamins are characterized by their solubility in fats and oils and are stored in the body’s liver and fatty tissues. They are crucial for various body functions, including vision, bone health, blood clotting, and antioxidant activity, highlighting their diverse and vital roles in maintaining health.

Vitamin K Deficiency

A deficiency in Vitamin K can manifest as symptoms like delayed blood clotting and excessive bleeding. The role of Vitamin K is critical as it is essential for the formation of clotting factors in the blood, which is vital for preventing uncontrollable bleeding. Additionally, Vitamin K plays a significant role in bone metabolism, highlighting its importance in overall health and bodily functions.

---

LAQ-8 : Explain the process of Photosynthesis in with the help of a flow chart? (OR) Give the mechanism of photosynthesis along with diagram.

Introduction

Photosynthesis is a crucial process in green plants, where they form complex organic molecules from simple inorganic molecules using sunlight. This fundamental mechanism sustains life on Earth by producing oxygen and serving as a primary source of food for plants and other organisms. It comprises two main phases: the light-dependent phase and the light-independent phase (Calvin Cycle).

Light-Dependent Phase

The light-dependent phase occurs in the grana of chloroplasts and involves light-based reactions. Here, chlorophyll absorbs photons (light energy), leading to the production of oxygen, NADPH, and ATP.

• Step-I: Activation of chlorophyll by absorbing photons.
• Step-II: Photolysis of water molecules, releasing oxygen and forming NADPH and ATP.

Explanation

Chlorophyll absorbs light energy, which activates photosynthesis. The photolysis reaction splits water molecules into oxygen and hydrogen. Oxygen is released as a byproduct, while hydrogen aids in converting NADP to NADPH. ATP, an energy-rich compound, is also produced, fueling the next photosynthesis phase.

Light-Independent Phase (Calvin Cycle)

The light-independent phase occurs in the stroma of chloroplasts and does not require light. It uses hydrogen from NADPH, carbon dioxide (CO2), and ATP to produce glucose.

• Process: Hydrogen combines with CO2, using ATP energy, to form glucose (C6H12O6).
• Glucose serves as an energy source and can be converted into starch for storage.

Explanation

This phase involves the Calvin Cycle, a series of reactions converting CO2 into glucose using ATP and NADPH from the light-dependent phase. Several enzymes and intermediate compounds are involved, culminating in glucose production.

Summary

Photosynthesis is a process that transforms light energy into chemical energy, resulting in the formation of glucose from inorganic molecules. It consists of two phases: the light-dependent phase, producing oxygen, NADPH, and ATP, and the light-independent phase (Calvin Cycle), leading to glucose production. This process is essential for the sustenance of life on Earth, highlighting the interdependence of these phases.