Table of Contents
Nutrition in Plants Questions with Answers – Short Answer Worksheet
Question – What is nutrition in plants?
Answer- Nutrition in plants refers to the process by which plants obtain and utilise essential substances for their growth, development, and metabolic activities.
Question – Why is proper nutrition vital for plants?
Answer- Proper nutrition is vital for plants because it provides them with the necessary energy, building materials, and nutrients to carry out essential functions such as photosynthesis, respiration, and reproduction. It also affects the overall health, strength, and resistance of plants to diseases and environmental stresses.
Question – How are nutrients broadly classified for plants?
Answer- Nutrients for plants can be broadly classified into two categories- macronutrients and micronutrients.
Question – What are macronutrients?
Answer- Macronutrients are nutrients needed in relatively large quantities by plants. They include carbon (C), hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg).
Question – What are micronutrients?
Answer- Micronutrients are nutrients required in smaller quantities by plants. They include iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), molybdenum (Mo), boron (B), and chlorine (Cl).
Question – Name two macronutrients necessary for photosynthesis.
Answer- Two macronutrients necessary for photosynthesis are carbon (C) and Nitrogen (N).
Question – Name two macronutrients necessary for protein synthesis in plants.
Answer- Two macronutrients necessary for protein synthesis in plants are nitrogen (N) and potassium (K).
Question – Which macronutrient is important for cell wall formation in plants?
Answer- Calcium (Ca) is important for cell wall formation in plants.
Question – Which macronutrient is an essential component of chlorophyll?
Answer- Magnesium (Mg) is an essential component of chlorophyll.
Question – What is photosynthesis?
Answer- Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy from the sun into chemical energy in the form of glucose.
Question – What is the role of chlorophyll in photosynthesis?
Answer- Chlorophyll is a green pigment found in chloroplasts that captures light energy from the sun. It absorbs light energy from the blue and red regions of the electromagnetic spectrum and reflects green light, allowing plants to utilise the absorbed energy for photosynthesis.
Question – What are the two main stages of photosynthesis?
Answer- The two main stages of photosynthesis are the light-dependent reactions and the light-independent reactions (Calvin cycle).
Question – Which molecules are converted into glucose and oxygen during photosynthesis?
Answer- Carbon dioxide (CO2) and water (H2O) are converted into glucose (C6H12O6) and oxygen (O2) during photosynthesis.
Question – Which region(s) of the electromagnetic spectrum does chlorophyll absorb light from?
Answer- Chlorophyll absorbs light energy from the blue and red regions of the electromagnetic spectrum.
Question – What is the function of photosystems in chloroplasts?
Answer- Photosystems are specific structures containing proteins and pigments that work together to convert light energy into chemical energy during photosynthesis.
Question – What is the primary source of energy for photosynthesis?
Answer- Sunlight.
Question – Which wavelengths of light do plants particularly absorb for photosynthesis?
Answer- Plants absorb light in the red and blue range of the spectrum.
Question – What are stomata, and what is their role in gas exchange?
Answer– Stomata are tiny openings found on the surfaces of leaves, stems, and other plant organs. They play a crucial role in the exchange of gases between plants and the environment.
Question – How does transpiration contribute to the process of photosynthesis?
Answer- Transpiration helps maintain the concentration of carbon dioxide in the leaf required for efficient photosynthesis.
Question – How do roots absorb water and minerals from the soil?
Answer- Roots absorb water through osmosis and minerals through active transport and passive diffusion.
Question – What is the photosynthesis equation?
Answer- 6CO2 + 6H2O -> C6H12O6 + 6O2.
Question – What are the reactants and products in the photosynthesis equation?
Answer– The reactants are carbon dioxide (CO2) and water (H2O), and the products are glucose (C6H12O6) and oxygen (O2).
Question – Where do plants get carbon dioxide from for photosynthesis?
Answer- Plants get carbon dioxide from the air through tiny openings called stomata.
Question – What is the main product of photosynthesis?
Answer- Glucose (C6H12O6).
Question – What happens to the oxygen produced during photosynthesis?
Answer- Oxygen is released into the atmosphere as a waste product.
Question – What are the three essential nutrients synthesised by plants other than carbohydrates?
Answer- The three essential nutrients synthesised by plants other than carbohydrates are proteins, fats (lipids), and vitamins.
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Question – What is the role of proteins in plant growth and development?
Answer- Proteins play a crucial role in plant growth and development as they are involved in various physiological processes, such as the function of enzymes, cell signalling, and the transport of molecules. They also contribute to the structure and functioning of cells.
Question – What are lipids and why are they important for plants?
Answer- Lipids, also known as fats, are important nutrients synthesised by plants. They serve as a source of energy and are involved in various metabolic processes. Lipids play a crucial role in membrane formation, energy storage, and protection from environmental stressors.
Question – Name two types of vitamins synthesised by plants.
Answer- Two types of vitamins synthesised by plants are vitamin C and various types of vitamin B.
Question – Why are proteins considered the building blocks of plant cells?
Answer- Proteins are considered the building blocks of plant cells because they are involved in numerous processes such as photosynthesis, respiration, DNA replication, and the regulation of plant growth hormones. They are necessary for the formation of new tissues and the repair of damaged tissues.
Question – Define heterotrophic nutrition in plants.
Answer- Heterotrophic nutrition is a form of nutrition in which plants obtain their food from external sources. Unlike autotrophic plants that can synthesise their own food, heterotrophic plants rely on preformed organic matter for their nutrition.
Question – Name three examples of parasitic plants.
Answer- Three examples of parasitic plants are mistletoe, dodder, and Rafflesia.
Question – How do insectivorous plants obtain essential nutrients?
Answer- Insectivorous plants obtain essential nutrients by capturing and digesting insects or other small organisms. They have specialised structures, such as modified leaves or pitchers, sticky glands, or trapping mechanisms, to catch their prey. Once trapped, they secrete enzymes to break down the captured organism and extract the nutrients.
Question – What is saprotrophic nutrition?
Answer- Saprotrophic nutrition is a type of nutrition in which plants obtain their food by decomposing dead organic matter. They secrete enzymes that break down complex organic compounds into simpler substances and absorb the resulting nutrients for their own growth and development.
Question – What is the role of decomposers in saprotrophic nutrition?
Answer- Decomposers play a crucial role in saprotrophic nutrition by recycling nutrients and breaking down organic material. They decompose dead plants, animals, and other organic materials, releasing important elements back into the soil and enriching it for the benefit of other organisms, including plants.
Question – What are symbiotic relationships in plant nutrition?
Answer- Symbiotic relationships in plant nutrition refer to mutually beneficial interactions between different species. Certain plants form symbiotic relationships with other organisms, such as nitrogen-fixing bacteria, mycorrhizal fungi, or cyanobacteria, to obtain essential nutrients while providing energy or protection in return.
Question – What is the symbiotic relationship involved in the formation of lichens?
Answer- Lichens are formed by a symbiotic association between a fungus and an alga or cyanobacterium.
Question – Name the two vascular tissues responsible for nutrient transport in plants.
Answer- Xylem and phloem are the two vascular tissues responsible for nutrient transport in plants.
Question – What is the function of xylem in plants?
Answer- Xylem transports water and minerals from the roots to the rest of the plant.
Question – Name the process through which food substances are transported in plants.
Answer- The process is called translocation.
Question – What is the pressure flow mechanism?
Answer- The pressure flow mechanism is the process through which sugars are transported in the phloem from sources to sinks.
Question – How do plants replenish the nutrient content in the soil?
Answer- Plants absorb minerals and nutrients from the soil through their roots, and farmers and gardeners replenish the nutrient content by adding fertilisers and manures to the soil.
Question – Name the bacteria responsible for nitrogen fixation in plants.
Answer- Rhizobium bacteria are responsible for nitrogen fixation in plants.
Question – What is the significance of the symbiotic relationship between Rhizobium bacteria and leguminous plants?
Answer- The symbiotic relationship allows leguminous plants to obtain fixed nitrogen from Rhizobium bacteria, reducing the need for synthetic nitrogen fertilisers and enriching the soil.
Question – Why are leguminous plants important in agriculture?
Answer- Leguminous plants can form a symbiotic relationship with Rhizobium bacteria, allowing them to acquire nitrogen from the atmosphere and enrich the soil. They are also a source of legumes (dals) that are important in the human diet.
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Nutrition in Plants Questions with Answers – Long Answer Worksheet
Question – Explain the process of photosynthesis in detail.
Answer- Photosynthesis is a complex biochemical process that occurs in the chloroplasts of plant cells. It involves two main stages- the light-dependent reactions and the light-independent reactions (Calvin cycle). During the light-dependent reactions, light energy is absorbed by chlorophyll and other pigments in the chloroplasts. This energy is used to split water molecules into oxygen and hydrogen ions, releasing oxygen as a byproduct. The energy from the absorbed light is also used to generate ATP (adenosine triphosphate), a molecule that stores energy. The hydrogen ions produced during the light-dependent reactions are used in the light-independent reactions, also known as the Calvin cycle. In the Calvin cycle, carbon dioxide is fixed and converted into glucose using the ATP and hydrogen ions generated earlier. The glucose produced serves as an energy source for the plant and is used for growth and other metabolic processes.
Question – Discuss the role of macronutrients in plant nutrition.
Answer- Macronutrients are essential nutrients required by plants in relatively large quantities. Carbon (C), hydrogen (H), and oxygen (O) are the primary elements needed for the formation of organic compounds such as carbohydrates, proteins, fats, and vitamins. Nitrogen (N) is crucial for the synthesis of proteins, enzymes, and chlorophyll. Phosphorus (P) is involved in energy transfer, DNA, RNA, and ATP synthesis. Potassium (K) plays a role in osmoregulation, enzyme activation, and protein synthesis. Calcium (Ca) is required for cell wall formation, membrane stability, and enzyme activation. Magnesium (Mg) is an essential component of chlorophyll and is involved in photosynthesis. These macronutrients provide the building blocks and energy necessary for plant growth, development, and metabolic activities.
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Question – Elaborate on the importance of micronutrients in plant metabolism.
Answer- Micronutrients, although required in smaller quantities, play crucial roles in various metabolic functions and enzyme activities in plants. Iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), molybdenum (Mo), boron (B), and chlorine (Cl) are micronutrients that are essential for enzyme activation, electron transport, and other metabolic reactions. For example, iron is involved in chlorophyll synthesis and electron transport in photosynthesis. Zinc is necessary for protein synthesis and enzyme activity. Copper functions as a cofactor for several enzymes involved in plant metabolism. Manganese is required for oxygen evolution in photosynthesis. Molybdenum is essential for nitrogen fixation and nitrate reduction. Boron plays a role in cell wall formation and carbohydrate transport. Chlorine is involved in photosynthesis and osmotic regulation. Although these micronutrients are required in smaller quantities, their deficiency can have significant impacts on plant growth, development, and overall health.
Question – Describe the role of chlorophyll in photosynthesis.
Answer- Chlorophyll is a green pigment found in the chloroplasts of plant cells. It plays a crucial role in capturing light energy from the sun during photosynthesis. Chlorophyll molecules absorb light energy from the blue and red regions of the electromagnetic spectrum while reflecting green light, giving plants their characteristic green colour. The absorbed light energy is then used to power the chemical reactions of photosynthesis. Chlorophyll molecules are arranged in specific structures called photosystems within the thylakoid membranes of chloroplasts. These photosystems contain proteins and other pigments that work together to convert light energy into chemical energy. Chlorophyll acts as the primary pigment in photosystems and captures photons, initiating the series of reactions that lead to the synthesis of glucose and the release of oxygen.
Question – Explain the process of nutrient absorption by plants.
Answer- Nutrient absorption by plants occurs primarily through the roots. Plant roots have specialised structures called root hairs, which increase the surface area for nutrient absorption. Nutrients, including minerals, are present in the soil in various forms. Plants take up these nutrients through active and passive mechanisms. Active absorption involves the expenditure of energy by the plant to transport specific ions against concentration gradients. Passive absorption occurs through diffusion, where nutrients move from an area of higher concentration to an area of lower concentration. The root system of plants also establishes symbiotic associations with beneficial soil microorganisms, such as mycorrhizal fungi, which enhance nutrient uptake. Once inside the root, nutrients are transported to other parts of the plant through the xylem and phloem tissues, ensuring their distribution to various tissues and organs.
Question – Explain the role of sunlight in photosynthesis and how it is converted into chemical energy.
Answer- Sunlight is the primary source of energy for photosynthesis. It provides the necessary light energy that chlorophyll pigments can absorb and convert into chemical energy. Plants absorb light in the red and blue range of the spectrum, while green light is reflected or transmitted. The absorbed light energy powers the light-dependent reactions of photosynthesis, where water molecules are split, releasing oxygen and producing energy-rich molecules such as ATP and NADPH. These energy carriers are then used in the light-independent reactions to convert carbon dioxide into glucose.
Question – Describe the role of stomata in gas exchange and how they control the entry of carbon dioxide and the exit of oxygen and water vapour.
Answer- Stomata are tiny openings found on the surfaces of leaves, stems, and other plant organs. They play a crucial role in the exchange of gases between plants and the environment. Each stoma consists of two specialised cells called guard cells that surround an opening known as the stomatal pore. When the guard cells take up water, they become turgid, causing the stomatal pore to open, allowing carbon dioxide to enter the leaf for photosynthesis. Conversely, the guard cells become flaccid when they lose water, causing the closure of the stomatal pore and reducing water loss through transpiration.
Question – Explain the process of transpiration in plants and its connection to photosynthesis.
Answer- Transpiration is the process by which plants lose water vapour through their leaves, mainly through the stomata. Transpiration serves several important functions in plants. Firstly, it helps cool the plant through evaporative cooling. Secondly, it creates a traction force known as transpiration pull, aiding the upward movement of water and minerals from the roots to the leaves through the xylem vessels. Thirdly, transpiration facilitates the transport of nutrients and minerals throughout the plant. Additionally, transpiration is closely connected to photosynthesis as plants open their stomata to allow the entry of carbon dioxide, leading to a loss of water vapour through transpiration. This loss of water is necessary for the plant to maintain the concentration of carbon dioxide required for efficient photosynthesis.
Question – Describe the process of water and mineral absorption through roots and their subsequent transport in plants.
Answer- Roots play an important role in absorbing water and minerals from the soil. They have root hairs that greatly increase the surface area for absorption. Water absorption occurs through osmosis, where the root hairs create a concentration gradient by actively transporting mineral ions from the soil into the root cells, increasing the solute concentration. This allows water from the soil to enter the roots by osmosis. Mineral absorption occurs through active transport and passive diffusion. Active transport involves the movement of mineral ions against the concentration gradient and requires energy. Passive diffusion occurs when mineral ions move from an area of higher concentration to an area of lower concentration without requiring energy. Once water and minerals are absorbed by the roots, they are transported upwards through the xylem vessels to the rest of the plant, driven by the transpiration pull.
Question – Explain the photosynthesis equation and the conversion of carbon dioxide and water into glucose and oxygen.
Answer- The photosynthesis equation is 6CO2 + 6H2O -> C6H12O6 + 6O2. In this equation, the reactants are carbon dioxide (CO2) and water (H2O), and the products are glucose (C6H12O6) and oxygen (O2). During photosynthesis, plants use light energy, chlorophyll, and other pigments to convert carbon dioxide and water into glucose and oxygen. Carbon dioxide is obtained from the air through stomata, while water is absorbed from the soil through the roots. Glucose is a simple sugar and the main product of photosynthesis, serving as an energy-rich molecule. Oxygen is released as a by-product and is essential for life on Earth.
Question – Explain the synthesis and importance of proteins in plant growth and development.
Answer- Proteins are macromolecules made up of amino acids that are crucial for the structure and functioning of cells. Plants synthesise proteins from amino acids they produce themselves or obtain from the soil. Proteins play a vital role in plant growth and development as they are involved in various physiological processes, such as the function of enzymes, cell signalling, and the transport of molecules. They act as building blocks of plant cells, tissues, and organs. Proteins are also involved in processes like photosynthesis, respiration, DNA replication, regulation of plant growth hormones, defence against pests and diseases, and the formation and repair of tissues.
Question – Discuss the role of fats (lipids) in plants, including their functions and significance.
Answer- Fats, also known as lipids, are another important class of nutrients synthesised by plants. They serve as a source of energy and are involved in various metabolic processes. Plants produce different types of lipids, including oils and waxes. Lipids play a crucial role in membrane formation, providing structural integrity to cells. They regulate the movement of substances in and out of cells. Additionally, lipids are involved in signalling processes within the plant. They also act as insulation against temperature fluctuations. Stored fats in plants are broken down during high energy demand, such as seed germination or growth spurts.
Question – Explain the synthesis and significance of vitamins in plant growth and development.
Answer- Plants synthesise certain vitamins, which are organic compounds necessary for various physiological functions. Vitamins act as coenzymes or cofactors that facilitate the activity of enzymes and support metabolic reactions in plants. They are involved in growth, reproduction, and defence mechanisms. Vitamins also help plants tolerate stress and play a role in the synthesis of other important compounds. For example, vitamin C is involved in the synthesis of plant hormones and acts as an antioxidant, protecting plants from oxidative damage. Vitamins are crucial for the overall growth, development, and defence against pathogens in plants.
Question – Explain the concept of heterotrophic nutrition in plants, including its definition and how it differs from autotrophic nutrition.
Answer- Heterotrophic nutrition is a form of nutrition in which plants obtain their food from external sources. Unlike autotrophic plants, which can synthesise their own food through processes like photosynthesis, heterotrophic plants rely on preformed organic matter for their nutrition. They are not capable of photosynthesis and thus cannot produce their own food. Instead, heterotrophic plants obtain nutrients by directly absorbing or ingesting organic substances from their surroundings.
Question – Describe the adaptations and examples of parasitic plants, including their mode of obtaining nutrients and survival in nutrient-poor environments.
Answer- Parasitic plants are plants that obtain their nutrients from attachment to other plants, called host plants. They make connections with the vascular system of the host plant to obtain water, nutrients, and other essential compounds. Parasitic plants have little or no chlorophyll, making them unable to perform photosynthesis effectively. Examples of parasitic plants include mistletoe, dodder, and Rafflesia. These plants have adaptations such as specialised roots or structures called haustoria that penetrate the host plant’s tissues to obtain water and nutrients. The parasitic lifestyle allows them to survive in nutrient-poor environments by relying on the host plant for their nutritional needs.
Question – Discuss the unique adaptations of insectivorous (carnivorous) plants, their role in nutrient acquisition, and their habitat preferences.
Answer- Insectivorous plants, also known as carnivorous plants, have evolved unique adaptations to capture and digest insects or other small organisms. These plants typically grow in habitats with nutrient-poor soils and have evolved carnivorous traits to find an alternative source of essential nutrients, especially nitrogen. Insectivorous plants have specialised structures such as modified leaves or pitchers, sticky glands, or trapping mechanisms to catch their prey. Once the prey is trapped, they secrete enzymes to break down the captured organism and extract the nutrients. Examples of insectivorous plants include the Venus flytrap, pitcher plants, and sundews.
Question – Explain saprotrophic nutrition in plants, including its definition, process, and the role of decomposers.
Answer- Saprotrophic nutrition is a type of nutrition in which plants obtain their food by decomposing dead organic matter. Saprotrophic plants, also known as decomposers, secrete enzymes that break down complex organic compounds into simpler substances. They absorb the resulting nutrients for their own growth and development. Decomposers play a crucial role in saprotrophic nutrition by recycling nutrients and breaking down organic material. They decompose dead plants, animals, and other organic materials, releasing important elements back into the soil. This process of nutrient recycling enriches the soil and makes nutrients available to other organisms, including plants. Common examples of saprotrophic plants are fungi such as mushrooms and moulds, as well as certain bacteria.
Question – Discuss the concept of symbiotic relationships in plant nutrition, providing examples and the benefits for the participating organisms.
Answer- Symbiotic relationships are mutually beneficial interactions between different species. In the context of plant nutrition, certain plants enter into symbiotic relationships with other organisms to obtain essential nutrients. Symbionts, which can include nitrogen-fixing bacteria, mycorrhizal fungi, or cyanobacteria, form these relationships. Symbionts provide nutrients such as nitrogen, phosphorus, or organic compounds to the host plant, and in return, they receive energy or protection. For example, nitrogen-fixing bacteria form nodules on the roots of leguminous plants, supplying them with nitrogen while utilising the plant’s carbohydrates. Mycorrhizal fungi form symbiotic associations with plant roots, increasing the plant’s nutrient uptake capabilities. These symbiotic relationships benefit both the host plant and the symbiont by enhancing nutrient acquisition and overall plant growth.
Question – Explain the mutualistic relationship between a fungus and an alga or cyanobacterium in lichens.
Answer- Lichens are formed by a symbiotic association between a fungus and an alga or cyanobacterium. The fungus provides a protective structure and absorbs water and minerals, while the alga or cyanobacterium performs photosynthesis and provides organic matter. This mutualistic relationship allows lichens to thrive in harsh environments and contribute to soil formation and nutrient cycling.
Question – Describe the structure and function of xylem in plants.
Answer- Xylem is a vascular tissue responsible for transporting water and minerals from the roots to the rest of the plant. It consists of elongated cells called tracheary elements, which are dead cells with lignified walls. These cells are arranged end-to-end and form long tubes. Xylem relies on the cohesive and adhesive properties of water as well as transpiration to create a pull that helps water move upwards against gravity.
Question – Discuss the process of translocation and its importance in distributing food throughout the plant.
Answer- Translocation is the process of moving food substances, primarily sugars, through the phloem from sources (sites of sugar production, usually leaves) to sinks (sites of sugar utilisation or storage, such as growing roots, fruits, or storage tissues). It occurs through a process called the pressure flow mechanism. Sugar, mainly in the form of sucrose, is actively transported from the cells of origin into the sieve tube elements. This creates a higher sugar concentration in the phloem at the source end, resulting in water moving into the phloem by osmosis and creating a high hydrostatic pressure. The pressure gradient drives the movement of sugars from the source to the sink, where they are either utilised or stored. Translocation is crucial for the distribution of synthesised food from leaves to other plant parts, ensuring an even supply of nutrients for growth, repair, reproduction, and storage.
Question – Explain the significance of the symbiotic relationship between Rhizobium bacteria and leguminous plants.
Answer- Rhizobium bacteria play a crucial role in the process of nitrogen fixation, converting atmospheric nitrogen gas into a usable form that plants can absorb. To obtain necessary nitrogen, Rhizobium bacteria form a symbiotic relationship with leguminous plants. Leguminous plants provide a suitable habitat for Rhizobium bacteria in their root nodules, and in return, the bacteria provide fixed nitrogen to the plants. This symbiotic relationship is significant for farmers as it allows them to reduce the use of nitrogenous fertilisers in fields where leguminous plants are grown. The bacteria provide a natural and sustainable source of nitrogen, reducing the need for synthetic fertilisers and promoting soil enrichment.
Question – Discuss the importance of leguminous plants in agriculture and their role in nutrient enrichment.
Answer- Leguminous plants play a crucial role in agriculture due to their ability to form a symbiotic relationship with Rhizobium bacteria. This relationship enables leguminous plants to acquire nitrogen from the atmosphere and enrich the soil with this essential nutrient. Nitrogen is often deficient in agricultural soils, and the ability of leguminous plants to fix atmospheric nitrogen reduces the reliance on synthetic nitrogen fertilisers. Additionally, leguminous plants are a source of many legumes (dals), which are an important part of the human diet, providing dietary protein and other essential nutrients.
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