12th Biology Biotechnology Principles and Processes Part 5Vista's Learning
The document discusses the process of obtaining a foreign gene product through recombinant DNA technology. It explains that a foreign gene is inserted into a cloning vector and transferred into a host cell, where it gets expressed under appropriate conditions. Large scale production of the protein requires optimizing expression conditions and using bioreactors, which provide optimal growth conditions for high yields. Downstream processing is then needed to separate and purify the protein into a final formulated product.
12th Biology Biotechnology Principles and Processes Part 4Vista's Learning
Recombinant DNA technology involves isolating DNA from organisms, cutting it with restriction enzymes, ligating the cut DNA fragments into vectors, inserting the recombinant DNA into host cells, culturing the host cells to produce multiple copies, and extracting the desired product. Key steps include isolating pure DNA, cutting source and vector DNA with the same enzyme, ligating the gene of interest into the vector, amplifying the gene using PCR, transforming host cells to incorporate the recombinant DNA, and using selective markers like antibiotic resistance to identify transformed cells.
12th Biology Biotechnology Principles and Processes Part 3Vista's Learning
This document discusses cloning vectors used for introducing foreign DNA into host cells. It describes the key features cloning vectors require, such as an origin of replication to allow replication of the inserted DNA, selectable markers to identify recombinant cells, and restriction sites for inserting DNA. Common vectors discussed include plasmids, bacteriophages, and modified pathogens like Agrobacterium tumifaciens that can transfer DNA to plant cells. The document also covers making host cells competent for DNA uptake and different transformation methods for introducing recombinant DNA.
12th Biology Biotechnology Principles and Processes Part 2Vista's Learning
This document discusses the key tools used in recombinant DNA technology: restriction enzymes, polymerase enzymes, ligases, vectors, and host organisms. It focuses on restriction enzymes, explaining that they cut DNA at specific recognition sequences, leaving sticky ends that allow fragments to be joined together. DNA fragments produced by restriction enzymes can be separated by gel electrophoresis based on their size and then isolated for use in recombinant DNA construction.
12th Biology Biotechnology Principles and Processes part 1Vista's Learning
The document discusses the principles and processes of biotechnology. It defines biotechnology as using live organisms or enzymes to produce useful products and processes. Modern biotechnology uses genetic engineering techniques like recombinant DNA and gene cloning to isolate desirable genes and introduce them into host organisms. The two core techniques that enabled modern biotechnology are genetic engineering and bioprocess engineering. Genetic engineering allows isolation of single genes without introducing undesirable genes. The first recombinant DNA was constructed in 1972 by linking an antibiotic resistance gene to a plasmid, allowing the gene to replicate in E. coli.
Class 9 bio ch 3 diversity in living organisms part 1Vista's Learning
The document discusses characteristics used for classifying living organisms, including whether they have eukaryotic or prokaryotic cells, whether they are unicellular or multicellular, their means of obtaining food (autotroph or heterotroph) and their body organization. Some key early classifiers, like Aristotle, grouped organisms based on their habitat of land, water or air.
Class 9 bio ch 3 diversity in living organisms part 2Vista's Learning
This document discusses diversity in living organisms and covers classification, biodiversity, evolution, and the relationship between classification and evolution. It introduces the concept of classification, which groups organisms based on common features, and biodiversity, which refers to the variety of life in a particular environment. Evolution is described as changes in organism characteristics over time due to environmental changes that allow organisms to survive. The hierarchy of classification is explained, with the five kingdoms of life - Monera, Protista, Fungi, Plantae, and Animalia - that are further divided into subgroups like phylum, class, order, genus, and species.
Class 9 bio ch 3 diversity in living organisms part 3Vista's Learning
This document discusses the three kingdoms of living organisms - Monera, Protista, and Fungi. Kingdom Monera contains prokaryotic, unicellular organisms like bacteria and blue-green algae. Kingdom Protista is made up of eukaryotic, unicellular organisms like Paramecium and Euglena that may be photosynthetic or heterotrophic. Kingdom Fungi consists of eukaryotic, multicellular organisms with cell walls containing chitin, including mushrooms, lichens, and parasitic fungi.
12th Biology Biotechnology Principles and Processes Part 5Vista's Learning
The document discusses the process of obtaining a foreign gene product through recombinant DNA technology. It explains that a foreign gene is inserted into a cloning vector and transferred into a host cell, where it gets expressed under appropriate conditions. Large scale production of the protein requires optimizing expression conditions and using bioreactors, which provide optimal growth conditions for high yields. Downstream processing is then needed to separate and purify the protein into a final formulated product.
12th Biology Biotechnology Principles and Processes Part 4Vista's Learning
Recombinant DNA technology involves isolating DNA from organisms, cutting it with restriction enzymes, ligating the cut DNA fragments into vectors, inserting the recombinant DNA into host cells, culturing the host cells to produce multiple copies, and extracting the desired product. Key steps include isolating pure DNA, cutting source and vector DNA with the same enzyme, ligating the gene of interest into the vector, amplifying the gene using PCR, transforming host cells to incorporate the recombinant DNA, and using selective markers like antibiotic resistance to identify transformed cells.
12th Biology Biotechnology Principles and Processes Part 3Vista's Learning
This document discusses cloning vectors used for introducing foreign DNA into host cells. It describes the key features cloning vectors require, such as an origin of replication to allow replication of the inserted DNA, selectable markers to identify recombinant cells, and restriction sites for inserting DNA. Common vectors discussed include plasmids, bacteriophages, and modified pathogens like Agrobacterium tumifaciens that can transfer DNA to plant cells. The document also covers making host cells competent for DNA uptake and different transformation methods for introducing recombinant DNA.
12th Biology Biotechnology Principles and Processes Part 2Vista's Learning
This document discusses the key tools used in recombinant DNA technology: restriction enzymes, polymerase enzymes, ligases, vectors, and host organisms. It focuses on restriction enzymes, explaining that they cut DNA at specific recognition sequences, leaving sticky ends that allow fragments to be joined together. DNA fragments produced by restriction enzymes can be separated by gel electrophoresis based on their size and then isolated for use in recombinant DNA construction.
12th Biology Biotechnology Principles and Processes part 1Vista's Learning
The document discusses the principles and processes of biotechnology. It defines biotechnology as using live organisms or enzymes to produce useful products and processes. Modern biotechnology uses genetic engineering techniques like recombinant DNA and gene cloning to isolate desirable genes and introduce them into host organisms. The two core techniques that enabled modern biotechnology are genetic engineering and bioprocess engineering. Genetic engineering allows isolation of single genes without introducing undesirable genes. The first recombinant DNA was constructed in 1972 by linking an antibiotic resistance gene to a plasmid, allowing the gene to replicate in E. coli.
Class 9 bio ch 3 diversity in living organisms part 1Vista's Learning
The document discusses characteristics used for classifying living organisms, including whether they have eukaryotic or prokaryotic cells, whether they are unicellular or multicellular, their means of obtaining food (autotroph or heterotroph) and their body organization. Some key early classifiers, like Aristotle, grouped organisms based on their habitat of land, water or air.
Class 9 bio ch 3 diversity in living organisms part 2Vista's Learning
This document discusses diversity in living organisms and covers classification, biodiversity, evolution, and the relationship between classification and evolution. It introduces the concept of classification, which groups organisms based on common features, and biodiversity, which refers to the variety of life in a particular environment. Evolution is described as changes in organism characteristics over time due to environmental changes that allow organisms to survive. The hierarchy of classification is explained, with the five kingdoms of life - Monera, Protista, Fungi, Plantae, and Animalia - that are further divided into subgroups like phylum, class, order, genus, and species.
Class 9 bio ch 3 diversity in living organisms part 3Vista's Learning
This document discusses the three kingdoms of living organisms - Monera, Protista, and Fungi. Kingdom Monera contains prokaryotic, unicellular organisms like bacteria and blue-green algae. Kingdom Protista is made up of eukaryotic, unicellular organisms like Paramecium and Euglena that may be photosynthetic or heterotrophic. Kingdom Fungi consists of eukaryotic, multicellular organisms with cell walls containing chitin, including mushrooms, lichens, and parasitic fungi.
Class 9 bio ch 3 diversity in living organisms part 4Vista's Learning
This document discusses the five kingdoms of multicellular plants - Thallophyta, Bryophyta, Pteridophyta, Gymnosperms, and Angiosperms. It describes their classification based on characteristics like their differentiated body structures, transport tissues, seeds, and fruits. Specific examples are provided for each division, including algae for Thallophyta, mosses for Bryophyta, and ferns for Pteridophyta. Reproductive structures and life cycles are compared between cryptogams and phanerogams.
Class 9 bio ch 3 diversity in living organisms part 5Vista's Learning
The document discusses two divisions of plants - gymnosperms, which have naked seeds, and angiosperms, which have covered seeds. Gymnosperms are evergreen, woody plants like pines and deodars. Angiosperms are also called flowering plants and have a well differentiated plant body and cotyledons or seed leaves, and are classified as monocotyledons or dicotyledons based on the number of cotyledons.
Class 9 bio ch 3 diversity in living organisms part 6Vista's Learning
The document discusses the classification of organisms within the Kingdom Animalia. It describes how Animalia is divided into invertebrates and vertebrates. Several phyla are listed for each group. Specific details are provided about the phyla Porifera and Coelenterata. Porifera includes sponges, which are non-motile marine organisms with pores, chambers, and silicon/calcium skeletons. Coelenterata includes cnidarians like hydra and corals, which are aquatic animals with exoskeletons and internal cavities formed from two cell layers.
Class 5 Subject - EVS, CH Our India - Political and CulturalVista's Learning
India has great religious and cultural diversity. The major religions in India are Hinduism, Islam, Christianity, Sikhism, Buddhism, and Jainism. People of other faiths also live in India. The national flag of India represents this diversity with its saffron, white, and green colors. It also features the Ashoka Chakra in the center. India's national emblem is a four-faced lion from the Ashoka pillar at Saranath. India's culture varies greatly across states, each with their own unique dance, music, art, and literature traditions that represent India's rich heritage.
The document discusses the planets of the solar system and other celestial bodies. It provides details about each planet from Mercury to Neptune, including their composition, size, and notable features. It also describes meteoroids, asteroids, comets, and the moon - our only natural satellite. The moon revolves around Earth and reflects sunlight, causing its phases to change from new to full moon each month.
Class 5 Subject - EVS, CH - Our India - Physical DiversityVista's Learning
This document provides an overview of the physical geography and features of India. It describes the major physical regions of India, including the Northern Mountains (Himalayas), Northern Plains, Peninsular Plateau, and Coastal Plains. For each region, it outlines the geographic characteristics, major rivers, climate, vegetation, and how the natural environment has influenced human settlement patterns and way of life. The document uses maps and diagrams to illustrate the various mountain ranges, plateaus, plains, and river systems that make up India's diverse physical landscape.
1) The Thar Desert, located in northwest India, extends across parts of Rajasthan, Punjab, Haryana, and Gujarat.
2) Deserts are characterized by very little vegetation, high temperatures, dry climate, and scanty rainfall except for oases where water reaches the ground surface.
3) Camels are well-adapted to desert conditions, able to go long periods without food or water thanks to their broad toes, humps that store fat, and ability to carry goods and passengers, earning them the name "ship of the desert".
1) Matter expands when heated as demonstrated by an iron bob being able to pass through a ring only after being heated. Ice also melts when heated, changing from a solid to a liquid state.
2) The three common states of matter - solid, liquid, and gas - can change between each other when heated or cooled. For example, solids change to liquids when heated and liquids change to gases.
3) Some substances like naphthalene balls sublime by changing directly from solid to gas when heated without passing through the liquid state.
Class 5 Subject - EVS, CH - Nature of Matter Part2Vista's Learning
This document provides an overview of the nature of matter. It discusses that matter is made up of small particles and exists in three states: solid, liquid, and gas. The key points covered are:
- Matter is anything that occupies space and has mass. It is composed of tiny particles that are invisible to the naked eye.
- Solids have a definite shape and volume, liquids have a definite volume but take the shape of their container, while gases fill their container evenly.
- The document explores various properties of matter like occupying space, having mass, and existing in different states depending on the arrangement of particles. It provides examples to illustrate solid, liquid and gas states.
Class 5 Subject - EVS, CH - Elements, Compounds and MixturesVista's Learning
This document discusses the classification of matter into elements, compounds, and mixtures. It defines elements as substances made of identical atoms that cannot be broken down further. Compounds are formed by the chemical combination of two or more elements together in fixed ratios, with the constituents losing their individual properties. Mixtures are physical combinations of elements or compounds that retain their own properties and can be separated easily. Examples of each are given like gold as an element, water as a compound, and soil as a mixture.
The document discusses different forms of energy: electrical, bio, chemical, and fuel. It provides examples of each type. Bio energy is gas from decaying agricultural waste without air. Chemical energy comes from chemical reactions, like those in batteries. Fuel energy comes from combustible natural sources like firewood that produce heat and light. The document emphasizes that energy cannot be created or destroyed, only converted from one form to another, like fuel to mechanical or heat energy. It concludes that energy from natural sources like sun and wind should be used moderately to conserve it.
Class 12, subject chemistry chapter name solutions, topic name - solubility...Vista's Learning
1) The document discusses key concepts related to solutions including expressing concentration through mole fraction, molarity, and molality.
2) It also discusses solubility and how it is affected by factors like the nature of the solute and solvent, temperature, and pressure. When a solid solute dissolves in a liquid, it reaches a dynamic equilibrium where the concentration remains constant.
3) The document provides examples of how solubility is affected by temperature depending on whether the dissolution process is endothermic or exothermic based on Le Chatelier's principle. Pressure does not significantly impact solubility of solids in liquids.
Class 9 bio ch 3 diversity in living organisms part 4Vista's Learning
This document discusses the five kingdoms of multicellular plants - Thallophyta, Bryophyta, Pteridophyta, Gymnosperms, and Angiosperms. It describes their classification based on characteristics like their differentiated body structures, transport tissues, seeds, and fruits. Specific examples are provided for each division, including algae for Thallophyta, mosses for Bryophyta, and ferns for Pteridophyta. Reproductive structures and life cycles are compared between cryptogams and phanerogams.
Class 9 bio ch 3 diversity in living organisms part 5Vista's Learning
The document discusses two divisions of plants - gymnosperms, which have naked seeds, and angiosperms, which have covered seeds. Gymnosperms are evergreen, woody plants like pines and deodars. Angiosperms are also called flowering plants and have a well differentiated plant body and cotyledons or seed leaves, and are classified as monocotyledons or dicotyledons based on the number of cotyledons.
Class 9 bio ch 3 diversity in living organisms part 6Vista's Learning
The document discusses the classification of organisms within the Kingdom Animalia. It describes how Animalia is divided into invertebrates and vertebrates. Several phyla are listed for each group. Specific details are provided about the phyla Porifera and Coelenterata. Porifera includes sponges, which are non-motile marine organisms with pores, chambers, and silicon/calcium skeletons. Coelenterata includes cnidarians like hydra and corals, which are aquatic animals with exoskeletons and internal cavities formed from two cell layers.
Class 5 Subject - EVS, CH Our India - Political and CulturalVista's Learning
India has great religious and cultural diversity. The major religions in India are Hinduism, Islam, Christianity, Sikhism, Buddhism, and Jainism. People of other faiths also live in India. The national flag of India represents this diversity with its saffron, white, and green colors. It also features the Ashoka Chakra in the center. India's national emblem is a four-faced lion from the Ashoka pillar at Saranath. India's culture varies greatly across states, each with their own unique dance, music, art, and literature traditions that represent India's rich heritage.
The document discusses the planets of the solar system and other celestial bodies. It provides details about each planet from Mercury to Neptune, including their composition, size, and notable features. It also describes meteoroids, asteroids, comets, and the moon - our only natural satellite. The moon revolves around Earth and reflects sunlight, causing its phases to change from new to full moon each month.
Class 5 Subject - EVS, CH - Our India - Physical DiversityVista's Learning
This document provides an overview of the physical geography and features of India. It describes the major physical regions of India, including the Northern Mountains (Himalayas), Northern Plains, Peninsular Plateau, and Coastal Plains. For each region, it outlines the geographic characteristics, major rivers, climate, vegetation, and how the natural environment has influenced human settlement patterns and way of life. The document uses maps and diagrams to illustrate the various mountain ranges, plateaus, plains, and river systems that make up India's diverse physical landscape.
1) The Thar Desert, located in northwest India, extends across parts of Rajasthan, Punjab, Haryana, and Gujarat.
2) Deserts are characterized by very little vegetation, high temperatures, dry climate, and scanty rainfall except for oases where water reaches the ground surface.
3) Camels are well-adapted to desert conditions, able to go long periods without food or water thanks to their broad toes, humps that store fat, and ability to carry goods and passengers, earning them the name "ship of the desert".
1) Matter expands when heated as demonstrated by an iron bob being able to pass through a ring only after being heated. Ice also melts when heated, changing from a solid to a liquid state.
2) The three common states of matter - solid, liquid, and gas - can change between each other when heated or cooled. For example, solids change to liquids when heated and liquids change to gases.
3) Some substances like naphthalene balls sublime by changing directly from solid to gas when heated without passing through the liquid state.
Class 5 Subject - EVS, CH - Nature of Matter Part2Vista's Learning
This document provides an overview of the nature of matter. It discusses that matter is made up of small particles and exists in three states: solid, liquid, and gas. The key points covered are:
- Matter is anything that occupies space and has mass. It is composed of tiny particles that are invisible to the naked eye.
- Solids have a definite shape and volume, liquids have a definite volume but take the shape of their container, while gases fill their container evenly.
- The document explores various properties of matter like occupying space, having mass, and existing in different states depending on the arrangement of particles. It provides examples to illustrate solid, liquid and gas states.
Class 5 Subject - EVS, CH - Elements, Compounds and MixturesVista's Learning
This document discusses the classification of matter into elements, compounds, and mixtures. It defines elements as substances made of identical atoms that cannot be broken down further. Compounds are formed by the chemical combination of two or more elements together in fixed ratios, with the constituents losing their individual properties. Mixtures are physical combinations of elements or compounds that retain their own properties and can be separated easily. Examples of each are given like gold as an element, water as a compound, and soil as a mixture.
The document discusses different forms of energy: electrical, bio, chemical, and fuel. It provides examples of each type. Bio energy is gas from decaying agricultural waste without air. Chemical energy comes from chemical reactions, like those in batteries. Fuel energy comes from combustible natural sources like firewood that produce heat and light. The document emphasizes that energy cannot be created or destroyed, only converted from one form to another, like fuel to mechanical or heat energy. It concludes that energy from natural sources like sun and wind should be used moderately to conserve it.
Class 12, subject chemistry chapter name solutions, topic name - solubility...Vista's Learning
1) The document discusses key concepts related to solutions including expressing concentration through mole fraction, molarity, and molality.
2) It also discusses solubility and how it is affected by factors like the nature of the solute and solvent, temperature, and pressure. When a solid solute dissolves in a liquid, it reaches a dynamic equilibrium where the concentration remains constant.
3) The document provides examples of how solubility is affected by temperature depending on whether the dissolution process is endothermic or exothermic based on Le Chatelier's principle. Pressure does not significantly impact solubility of solids in liquids.
4. 4
10ನೇ ತರಗತಿ, ಪ್ರಥಮ ಭಾಷೆ ಕನ್ನಡ
ಪ್ದ್ಯ 01
ಸಂಕಲ್ಪಗೇತೆ
ಚರಣ 02
ಕಲ್ುಷಿತವಾದಿೇ ನ್ದಿೇಜಲ್ಗಳಿೆ
ಮುಂಗಾರನ್ ಮಳೆಯಾೆ ೇಣ.
ಬರಡಾಗರುವಿೇ ಕಾಡುಮೇಡುಗಳಗ
ವಸಂತವಾಗುತ ಮುಟ ಟೇಣ.
ಕಲ್ುಷಿತ: ಮಾಲಿನ್ಯ ಆಗರುವ
ವಸಂತ: ಚಿಗುರುವ ಸಮಯ
“ಸಾರಾಂಶ”
ಪ್ರಸರಕೆೆ ಸಹಾಯ
ಮಾಡುತ್ಾತ ನಿೇರನ್ುನ,
ಕಾಡುಗಳಗನ್ುನ
ಸ ಂಪಾಗಸುವ
ಸಂಕಲ್ಪ
ಮಾಡಬೆೇಕು.
5. 5
10ನೇ ತರಗತಿ, ಪ್ರಥಮ ಭಾಷೆ ಕನ್ನಡ
ಪ್ದ್ಯ 01
ಸಂಕಲ್ಪಗೇತೆ
ಚರಣ 03
ಬಿದ್ುಾದ್ನ್ುನ ಮೇಲೆಬಿಿಸಿ ನಿಲಿಿಸಿ
ಹ ಸ ಭರವಸಗಳಗ ಕಟ ಟೇಣ.
ಮನ್ುಜರ ನ್ಡುವಣ ಅಡಡೆ ೇಡೆಗಳಗ
ಕೆಡವುತ ಸೇತುವೆಯಾೆ ೇಣ.
ಅಡಡೆ ೇಡೆ: ಅಡ್ಡಡಮಾಡುವ ಅಂಶಗಳಗು
ಸೇತುವೆ: ಎರಡನ್ುನ ಒಟ್ುಟ ಸೇರಸುವ ವಿಷ್ಯ
“ಸಾರಾಂಶ”
ಕುಗಿರುವ ಜನ್ರನ್ುನ
ಪ್ರೇತ್ಾಾಹಿಸಿ. ಜನ್ರನ್ುನ
ದ್ ರ ಮಾಡುವ
ಅಂಶಗಳಗನ್ುನ ಬಿೇಳಿಸಿ
ಎಲ್ಿರನ್ ನ
ಸೇರಸಿಕೆ ಳಗುುವ ಸಂಕಲ್ಪ
ಮಾಡಬೆೇಕು.
7. 7
10ನೇ ತರಗತಿ, ಪ್ರಥಮ ಭಾಷೆ ಕನ್ನಡ
ಪ್ದ್ಯ 01,
ಸಂಕಲ್ಪಗೇತೆ 02 “ಸಾರಾಂಶ”
ಧಮಮಗಳಗು ಬೆೇರ
ಬೆೇರ ದಾರಗಳಗು.
ನಾಳಿನ್ ಬೆಿ ಭಯ
ಇರುವವರೆ
ನಿರೇಕ್ಷೆಯನ್ುನ
ಮ ಡ್ಡಸುವ ಸಂಕಲ್ಪ
ಮಾಡಬೆೇಕು.
“01 ಸಾರಾಂಶ”
ಕೆಟ್ಟಗುಣಗಳಗಂಥ
ಕತತಲೆಯ ಮಧ್ಯಯ ಪ್ರೇತಿ
ಹಂಚುವ ಬೆಳಗಕಿನ್
ದಿೇಪ್ ನಾವಾಗುವ
ಸಂಕಲ್ಪ ಮಾಡಬೆೇಕು.
03 “ಸಾರಾಂಶ”
ಕುಗಿರುವ ಜನ್ರನ್ುನ
ಪ್ರೇತ್ಾಾಹಿಸಿ. ಜನ್ರನ್ುನ
ದ್ ರ ಮಾಡುವ
ಅಂಶಗಳಗನ್ುನ ಬಿೇಳಿಸಿ
ಎಲ್ಿರನ್ ನ
ಸೇರಸಿಕೆ ಳಗುುವ
ಸಂಕಲ್ಪ ಮಾಡಬೆೇಕು.
04 “ಸಾರಾಂಶ”
ಧಮಮಗಳಗು ಬೆೇರ
ಬೆೇರ ದಾರಗಳಗು.
ನಾಳಿನ್ ಬೆಿ ಭಯ
ಇರುವವರೆ
ನಿರೇಕ್ಷೆಯನ್ುನ
ಮ ಡ್ಡಸುವ ಸಂಕಲ್ಪ
ಮಾಡಬೆೇಕು.
8. 8
10ನೇ ತರಗತಿ, ಪ್ರಥಮ ಭಾಷೆ ಕನ್ನಡ
ಪ್ದ್ಯ 01
ಸಂಕಲ್ಪಗೇತೆ ಕವಿ ಪ್ರಚಯ
ಜಿ. ಎಸ್. ಶಿವರುದ್ರಪ್ಪ
ಜನ್ನ್ : 1926
ಸಥಳಗ : ಶಿಕಾರಪ್ುರ
ಕೃತಿಗಳಗು: ಸಾಮಗಾನ್,
ಚಲ್ುವು-ಒಲ್ವು,
ದೇವಶಿಲ್ಪ, ದಿೇಪ್ದ್ ಹಜ್ಜೆ,
ಅನಾವರಣ, ಸ ಂದ್ಯಮ
ಸಮೇಕ್ಷೆ ಇತ್ಾಯದಿ
ಆಯಾಭಾಗ: ಎದತುಂಬಿ
ಹಾಡ್ಡದನ್ು