NIOS Class 12 Biology Chapter 9 Solution – Nutrition in Plants – Mineral Nutrition
NIOS Class 12 Biology Solution Chapter 9 Nutrition in Plants – Mineral Nutrition . NIOS Class 12 Biology Chapter 9 Question Answers Download PDF. NIOS Class 12 Biology Notes.
Board |
NIOS |
Class |
12th (Higher Secondary) |
Subject |
Biology |
Topic |
Question Answer, Solution, Notes |
INTEXT 9.1
1.) What are nutrients ?
Ans: Nutrients are the chemical components of food, such as CO2, water, minerals, carbohydrates, protein, and lipids.
2.) Define aeroponics.
Ans: Aeroponics is a technique of growing plants with their roots supplied with moisture present in the air. The shoots of the rooted plants are exposed to air and the roots are inside the box having computer controlled humid atmosphere
3.) Why is it necessary to aerate nutrient solution in water culture?
Ans: It is necessary to aerate nutrient solution in water culture to supply oxygen in sufficient quantity.
INTEXT 9.2
1.) In which form do plants get oxygen?
Ans: Oxygen is absorbed in the molecular form from air or from water. It is also generated within a green plant during photosynthesis
2.) Molybdenum is a micronutrient. Give reason.
Ans: Molybdenum is a micronutrient because it is required by plant in very small quantity. 0.1 mg per gram of dry matter or less , while macronutrients are required in relatively large quantities.
3.)Why are carbon, oxygen, potassium and sulphur called macronutrients
Ans: Carbon, oxygen, potassium and sulphur called are calles macronutrients because macronutrients are required in relatively large quantities like one to 10 milligram per gram of dry matter.
INTEXT 9.3
1.) State any two metabolic processes for which mineral nutrition is required.
Ans: Different functions are carried out by essential components. They perform a variety of metabolic functions in plant cells, including the upkeep of cell turgidity, electron transport, membrane permeability, and enzyme activity.
2.) Which element is provided by NO2 and NH4 when taken up by plants?
Ans: Nitrogen is the element provided by NO2 and NH4 when taken up by plants.
3.) State any two functions of Ca2+ in plants
Ans: (i) The central lamella of cell walls, which connects the adjacent cells, is made up of calcium pectate.
(ii) Activates the enzymes necessary for the root and shoot tip to grow.
(iii ) Needed for the formation of a normal cell wall
INTEXT 9.4
1.) What is meant by ‘passive absorption’ of minerals by plants?
Ans: Passive Absorption is the initial and rapid phase wherein ions are absorbed
into the “outer space” of the cells, through the apoplast pathway. It does not require use of any metabolic energy.
2.) Name the minerals whose deficiency affects normal cell division.
Ans: Inhibition of cell division is caused due to lack or deficiency of N, K, B, S and Mo
3.) “Deficiency of K, Ca and Mg causes necrosis of leaves”. What does this statement mean
Ans: “ Deficiency of K, Ca and Mg causes necrosis of leaves means, The deficiency causes death of leaf tissues.
INTEXT 9.5
1.) Give one point of difference between autotrophic and heterotrophic nutrition.
Ans (i) Autotrophs synthesize their own food while heterotrophs depend on others for food
(ii) Green plants obtain energy from sunlight and therefore are called photoautotrophs while the mode of nutrition is called heterotrophic nutrition in heterotrops.
2.) Name a plant which exhibits parasitic mode of nutrition.
Ans: Parasitic plant are those that lacks both chlorophyll and leaves .eg. Cuscuta (dodder)
3.) Why does pitcher plant eat insects when it is capable of carrying out Photosynthesis
Ans: Pitcher plant eat insects when it is capable of carrying out Photosynthesis because it grows in a nitrogen deficient habitat.
TERMINAL EXERCISE
1.) Which element can be obtained from both mineral and non-mineral sources.
Ans: Oxygen can be obtained from both mineral and non-mineral sources.
2.) Deficiency of which essential element causes yellowing of leaves in certain plants and why?
Ans: element causes yellowing of leaves in certain plants are K, Mg, N, S, Fe, Mn, Zn and Mo. These elements are required to make chlorophyll , absence of chlorophyll is called chlorosis.
3.) Why is magnesium included among essential elements?
Ans: Magnesium is a component of the chlorophyll molecule. opens up the enzymes ofPhosphorus metabolism. crucial for the production of DNA and RNA. necessary for the ribosomal subunits to bind.
4.) What are the criteria of essentiality of elements?
Ans: A essential element serves a variety of purposes. They perform a variety of metabolic tasks in plant cells, including maintaining the rigidity of the cell, moving electrons, maintaining membrane permeability, and enzymatic activity. Important components of coenzymes and biomolecules are also essential elements.
5.) Differentiate between micro and macro nutrients
Ans:
Micro nutrients | Macro nutrients |
They required in negligible concentrations, such as 0.1 mg per gramme of dry matter or less. additionally known as trace elements. | They Relatively high concentrations, such as one to ten milligrammes per gramme, are necessary. |
Eg : Manganese, Boron, cobatt | Eg: Carbon, Hydrogen, Oxygen |
6.) Why do biologists grow plants by hydroponics technique?
Ans: Hydroponics is a method for growing plants in a nutrient solution without any soil at all. Biologists grow plants by hydroponics technique because Symptoms of a deficiency arise when one or more of the required components is lacking. Hydroponics is a method for studying the symptoms.
7.) Explain the uptake of mineral nutrients by the plants.
Ans: Plants take up a lot of minerals from the soil. The roots’ uptake of mineral ions might be passive or Active. (a) Passive Absorption: This is the initial and quick phase of ion absorption into the cellular “outer space” via the apoplast route. It doesn’t need any metabolic energy to function. (b) The second stage of ion uptake is known as active absorption, The ions are gently absorbed into the ‘inner space’ of the symplast of cells. It requires the use of metabolic energy.
8.) Give the deficiency symptoms of nitrogen, phosphorus and potassium.
Ans: Retarded plant growth caused by the deficiency of nitrogen, phosphorus and potassium.
9.) Differentiate between the different modes of heterotrophic nutrition in plants.
Ans: the organisms whose organic nourishment depends on some other external sources. These organisms are known as heterotrophic plants, and their method of nutrition is known as heterotrophic nutrition.
a) Saprophytes are plants that thrive on dead organic matter, such as plant and animal remnants. The majority of these plants release enzymes that convert complicated chemical compounds into simpler ones. The plants then take up the simple form. Saprophytes include mainly fungi and bacteria.
b) Parasitic plant that lacks both chlorophyll and leaves. It is a yellow colour climber that attaches itself to the host. It gives out haustoria or the suckers that get attached to the phloem of the host and derive nutrition. Dodder (Cuscuta) known locally as Amarbel/Akashbel is a parasitic plant
10.) Write notes on :
(i) Aeroponics: Aeroponics is a method of producing plants where the moisture in the air is used to feed the roots.
(ii) Insectivorous plants: These are autotrophic plants that evolved insect-trapping characteristics to compensate for the soil’s lack of nitrogen. They eat insects for food.
(iii) Active absorption of minerals by plants: The second stage of ion uptake is known as active absorption, The ions are gently absorbed into the ‘inner space’ of the symplast of cells. It requires the use of metabolic energy.
Also See: Next Chapter No. 10 Question Answer