Class 6 Science Chapter 1 Question Answers - Nutrition in Plants

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Autotrophic nutrition is the process by which organisms can produce their own food using simple inorganic substances such as water, carbon dioxide, and sunlight, without the need for external sources of nutrients.

Q.2. What is photosynthesis?

Photosynthesis is the process by which green plants and some other organisms convert light energy into chemical energy in the form of glucose, which is used as food by the organism.

Q.3. What is heterotrophic nutrition?

Heterotrophic nutrition is the process by which organisms obtain food by consuming other organisms or organic matter.

Q.4 What is nutrition?

Nutrition refers to the process by which organisms obtain food and convert it into energy for their growth, development, and other life processes.

Q.5. What is the difference between parasitic and saprophytic plants?

Parasitic plants obtain their nutrition by feeding on other living plants, while saprophytic plants obtain their nutrition by feeding on dead organic matter.

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Q.1. What is the importance of photosynthesis in plants? How does it contribute to the ecosystem? 

Photosynthesis is an important process in plants as it is responsible for the production of glucose, which is used as a source of energy for the plant. This energy is used for various metabolic processes, growth and development of the plant. Moreover, photosynthesis also produces oxygen, which is essential for the survival of all living organisms, including plants themselves.
Photosynthesis also plays a crucial role in the ecosystem. It is responsible for maintaining the balance of gases in the atmosphere, as it takes in carbon dioxide and releases oxygen. This oxygen is then utilized by animals for respiration, and the carbon dioxide produced by them is used by plants for photosynthesis. Thus, photosynthesis is a vital process that contributes to the proper functioning of the ecosystem.

Q.2.   Explain the process of nutrient absorption in plants. How do plants obtain nutrients from the soil? 

Nutrient absorption is the process by which plants take up essential nutrients from the soil. The root hairs present on the surface of the roots absorb these nutrients through the process of osmosis and diffusion.
Plants obtain nutrients from the soil in the form of ions. These ions enter the plant through the root hairs, which are in close contact with the soil. The absorption of these nutrients is facilitated by the presence of mycorrhizae, which are symbiotic associations between the roots of the plant and fungi. These fungi help in the absorption of nutrients by increasing the surface area of the roots and releasing enzymes that break down complex nutrients into simpler forms that can be absorbed by the plant.

Q.3. What are the necessary conditions for photosynthesis to occur? Explain each condition briefly.

Photosynthesis is a complex process that requires certain conditions to occur. These necessary conditions are as follows:
a. Light - Light is essential for photosynthesis to occur. It is absorbed by the pigments present in the chloroplasts, which convert the light energy into chemical energy.
b. Chlorophyll - Chlorophyll is the pigment responsible for absorbing light energy during photosynthesis. It is present in the chloroplasts of green plants.
c. Carbon dioxide - Carbon dioxide is the source of carbon used by plants to produce glucose during photosynthesis. It is taken in by the leaves of the plant through small openings called stomata.
d. Water - Water is another essential ingredient for photosynthesis to occur. It is taken in by the roots of the plant and transported to the leaves, where it is used in the light-dependent reactions of photosynthesis.
e. Temperature - Temperature affects the rate of photosynthesis. Optimum temperature ranges from 20-25°C. At lower temperatures, the rate of photosynthesis decreases, while at higher temperatures, enzymes can denature, leading to a decrease in the rate of photosynthesis.

Q.4.  Describe autotrophic nutrition in detail. Provide an example of an autotrophic plant and explain how it obtains its food.

Autotrophic nutrition is a mode of nutrition in which an organism is able to synthesize its own food from simple inorganic substances such as water and carbon dioxide. The organisms that follow this mode of nutrition are called autotrophs.
An example of an autotrophic plant is a green plant. Green plants are able to carry out photosynthesis and synthesize their own food using light energy, water, and carbon dioxide.
During photosynthesis, the chlorophyll present in the chloroplasts of the green plant absorbs light energy, which is used to convert water and carbon dioxide into glucose. This glucose is used by the plant as a source of energy and to build more complex molecules such as starch and cellulose.
Green plants obtain the water and carbon dioxide they need for photosynthesis through their roots and leaves, respectively. They are able to convert these simple inorganic substances into complex organic compounds through the process of photosynthesis.

Q.5. Explain the different types of heterotrophic plants.

There are four types of heterotrophic plants:
1. Parasitic plants: These plants obtain their food by tapping into the roots or stems of other plants. They use their specialized structures, called haustoria, to penetrate the host plant's tissues and extract water and nutrients.
Examples: Cuscuta (dodder), mistletoe, and Rafflesia.
2. Saprophytic plants: These plants obtain their food by decomposing dead organic matter. They secrete enzymes that break down the organic matter into simpler compounds, which are then absorbed by the plant.
Examples: Indian Pipe, Coral Root. 
3. Insectivorous plants: These plants obtain their food by trapping and digesting insects. They have adapted various mechanisms to trap insects, such as sticky surfaces, snap traps, and pitfall traps.
Examples: Venus Flytrap, Pitcher Plant
4. Symbiotic plants: These plants obtain their food by living in a mutually beneficial relationship with other organisms. For example, some plants have a mutualistic relationship with fungi, where the fungi provide the plant with nutrients in exchange for carbohydrates produced by the plant.