- The document discusses the different types of plant tissues, including meristematic tissue, protective tissue, parenchyma tissue, mechanical tissue, and vascular or conductive tissue.
- Meristematic tissue contains undifferentiated cells that can divide rapidly through mitosis. There are primary and secondary meristems. Primary meristems are located at tips and cause primary growth, while secondary meristems cause lateral or secondary growth.
- Protective tissues include epidermal tissue, periderm, and cork which cover the outer surfaces and protect against water loss, pathogens, and mechanical damage.
- Parenchyma is the least specialized tissue found in all plant organs and performs many functions including photosynthesis
2.2.4 cell wall UEC Senior 1 Biology 独中高一生物Yee Sing Ong
(1) The cell wall is a structure found outside the plasma membrane of plant cells that is made mainly of cellulose. (2) It functions to protect the cell and maintain its shape. (3) The primary cell wall is thin and flexible, while the secondary cell wall is thicker and laid down in mature cells.
The document provides information about the structure and function of cells. It discusses:
- The basic parts of prokaryotic and eukaryotic cells, including their genetic material, organelles, size, and whether they are unicellular or multicellular.
- The key structures of animal and plant cells, such as the cell membrane, nucleus, mitochondria, vacuoles, and in plant cells, the cell wall and chloroplasts.
- The functions of important organelles like the nucleus, which houses DNA; ribosomes, which produce proteins; and the endoplasmic reticulum and Golgi apparatus, which are involved in protein transport.
- Differences between animal and plant cells
Ch 08 - Cell : The unit of Life || Class 11 ||SAQIB AHMED
- Robert Hooke first observed cells in 1665 when examining a slice of cork under a microscope. He saw small compartments separated by walls, which he called cells.
- The Cell Theory, developed by Schleiden and Schwann, states that the cell is the basic unit of structure and function of living things, new cells arise from existing cells, and all organisms are composed of one or more cells.
- Cells come in two main types - prokaryotic cells which lack a nucleus and membrane-bound organelles, and eukaryotic cells which have a nucleus surrounded by a nuclear membrane and other membrane-bound structures.
GOLGI APPARATUS, LYSOSOMES AND VACUOLES SMGsajigeorge64
The Golgi apparatus, lysosomes, and vacuoles are important cell organelles.
The Golgi apparatus packages and modifies proteins and lipids from the endoplasmic reticulum. It is made up of stacked flattened sacs called cisternae. Lysosomes contain digestive enzymes and break down materials through intracellular digestion and autophagy. Vacuoles store waste and help maintain plant cell turgor pressure. Each organelle plays a vital role in the transport and breakdown of cellular materials.
Parenchyma, collenchyma, sclerenchyma, phloem, and xylem are the fundamental tissues in plants. Parenchyma cells perform photosynthesis and store products. Collenchyma and sclerenchyma provide structural support. Phloem transports food throughout the plant via sieve tubes and companion cells. Xylem transports water and minerals upwards via tracheids and vessels. These tissues work together to support and transport nutrients and water in plants.
The document discusses the different tissues and cells found in plant organs like flowers, stems, leaves, and roots. It describes the four main types of plant tissues: meristematic tissues which are undifferentiated and divide actively; permanent tissues including epidermal, ground, and vascular tissues; epidermal tissue forms the outer layer; ground tissue includes parenchyma, collenchyma, and sclerenchyma cells; and vascular tissue contains xylem and phloem cells.
Stem cells are undifferentiated cells that can differentiate into specialized cell types and can divide extensively to replenish dying cells. There are several types of stem cells including totipotent, pluripotent, multipotent, and unipotent stem cells which differ in their differentiation potential. Sources of stem cells include embryonic stem cells from the inner cell mass of blastocysts, adult stem cells from bone marrow, adipose tissue, dental pulp and blood, and amniotic fluid stem cells. Stem cells offer potential for regenerative medicine but also face limitations from ethical concerns and risk of tumor formation.
All living things are made up of cells, the basic unit of structure and function. Robert Hooke first observed cells in 1655 using a microscope to view cork. Cells contain various organelles that carry out essential functions - the cell membrane contains and protects the cell, the nucleus controls cell processes, mitochondria produce energy, and plant cells also have a cell wall and chloroplasts. While animal and plant cells share many organelles, plant cells have a cell wall and larger vacuoles. Microorganisms like bacteria can be single-celled, while large organisms have many specialized cells.
2.2.4 cell wall UEC Senior 1 Biology 独中高一生物Yee Sing Ong
(1) The cell wall is a structure found outside the plasma membrane of plant cells that is made mainly of cellulose. (2) It functions to protect the cell and maintain its shape. (3) The primary cell wall is thin and flexible, while the secondary cell wall is thicker and laid down in mature cells.
The document provides information about the structure and function of cells. It discusses:
- The basic parts of prokaryotic and eukaryotic cells, including their genetic material, organelles, size, and whether they are unicellular or multicellular.
- The key structures of animal and plant cells, such as the cell membrane, nucleus, mitochondria, vacuoles, and in plant cells, the cell wall and chloroplasts.
- The functions of important organelles like the nucleus, which houses DNA; ribosomes, which produce proteins; and the endoplasmic reticulum and Golgi apparatus, which are involved in protein transport.
- Differences between animal and plant cells
Ch 08 - Cell : The unit of Life || Class 11 ||SAQIB AHMED
- Robert Hooke first observed cells in 1665 when examining a slice of cork under a microscope. He saw small compartments separated by walls, which he called cells.
- The Cell Theory, developed by Schleiden and Schwann, states that the cell is the basic unit of structure and function of living things, new cells arise from existing cells, and all organisms are composed of one or more cells.
- Cells come in two main types - prokaryotic cells which lack a nucleus and membrane-bound organelles, and eukaryotic cells which have a nucleus surrounded by a nuclear membrane and other membrane-bound structures.
GOLGI APPARATUS, LYSOSOMES AND VACUOLES SMGsajigeorge64
The Golgi apparatus, lysosomes, and vacuoles are important cell organelles.
The Golgi apparatus packages and modifies proteins and lipids from the endoplasmic reticulum. It is made up of stacked flattened sacs called cisternae. Lysosomes contain digestive enzymes and break down materials through intracellular digestion and autophagy. Vacuoles store waste and help maintain plant cell turgor pressure. Each organelle plays a vital role in the transport and breakdown of cellular materials.
Parenchyma, collenchyma, sclerenchyma, phloem, and xylem are the fundamental tissues in plants. Parenchyma cells perform photosynthesis and store products. Collenchyma and sclerenchyma provide structural support. Phloem transports food throughout the plant via sieve tubes and companion cells. Xylem transports water and minerals upwards via tracheids and vessels. These tissues work together to support and transport nutrients and water in plants.
The document discusses the different tissues and cells found in plant organs like flowers, stems, leaves, and roots. It describes the four main types of plant tissues: meristematic tissues which are undifferentiated and divide actively; permanent tissues including epidermal, ground, and vascular tissues; epidermal tissue forms the outer layer; ground tissue includes parenchyma, collenchyma, and sclerenchyma cells; and vascular tissue contains xylem and phloem cells.
Stem cells are undifferentiated cells that can differentiate into specialized cell types and can divide extensively to replenish dying cells. There are several types of stem cells including totipotent, pluripotent, multipotent, and unipotent stem cells which differ in their differentiation potential. Sources of stem cells include embryonic stem cells from the inner cell mass of blastocysts, adult stem cells from bone marrow, adipose tissue, dental pulp and blood, and amniotic fluid stem cells. Stem cells offer potential for regenerative medicine but also face limitations from ethical concerns and risk of tumor formation.
All living things are made up of cells, the basic unit of structure and function. Robert Hooke first observed cells in 1655 using a microscope to view cork. Cells contain various organelles that carry out essential functions - the cell membrane contains and protects the cell, the nucleus controls cell processes, mitochondria produce energy, and plant cells also have a cell wall and chloroplasts. While animal and plant cells share many organelles, plant cells have a cell wall and larger vacuoles. Microorganisms like bacteria can be single-celled, while large organisms have many specialized cells.
The document provides information about plant and animal cells. It defines cells as the basic unit of living things and notes that plants and animals are made of cells. The key differences between plant and animal cells are that plant cells contain a cell wall and chloroplasts, which allow them to perform photosynthesis, while animal cells do not have these structures. Both plant and animal cells share other common cellular components including the cell membrane, cytoplasm, mitochondria, nucleus, and vacuoles.
Cells are the basic unit of structure and function of all living things. They contain organelles that allow specific functions like protein production, energy generation, waste digestion, and more. The cell membrane controls what enters and leaves the cell and provides structure and protection. Plant and animal cells differ in their additional structures - plant cells have cell walls and chloroplasts, while animal cells do not have cell walls.
Prokaryotic and Eukaryotic Algal cell structuregkumarimahesh
The document summarizes the cell structure of prokaryotic and eukaryotic algal cells. Prokaryotic cells like cyanobacteria have an outer cellular covering including a mucilaginous sheath and cell wall, as well as a cytoplasm differentiated into a pigmented chromoplasm and central colorless centroplasm containing DNA. Eukaryotic algal cells have a cell wall, plasma lemma, and protoplast containing organelles like a chloroplast, mitochondria, and flagella. The chloroplast contains thylakoids and pyrenoids and the cell has structures like an eyespot.
2.1 type of cells UEC Senior 1 Biology 独中高一生物 Yee Sing Ong
This document discusses the differences between prokaryotic and eukaryotic cells. Prokaryotic cells, such as bacteria and archaea, lack a nucleus and organelles. They have simpler DNA not organized into chromosomes and smaller ribosomes. Eukaryotic cells, which include plants, animals, fungi and protists, have a nucleus enclosed in a membrane as well as other membrane-bound organelles. They have larger DNA-protein complexes called chromosomes and larger ribosomes. The document provides examples of different types of prokaryotic and eukaryotic cells and outlines their key similarities and differences.
In this power point presentation Viewer will be able to know about the Plant Cell Constituents. How plants cells Composed with different organelles. What are the functions they have during the growth of particular plant. Plant cells are primary unit of the plant body and from here only we get medicinal value chemical constituents.
Portion Covered:
1. Plant Cells
2. Plant Cell Diagram
3. Plant cell Structure
4. Plant cell type
5. Plant cell Functions
This document defines cell modification and describes the three main types: apical, basal, and lateral modifications. It provides examples of each type of modification and their functions. Apical modifications include cilia, flagella, microvilli, and pseudopods, which increase surface area. Basal modifications are hemidesmosomes, which anchor the cell. Lateral modifications are tight junctions, adhering junctions, and gap junctions, which regulate movement between cells and allow cell-to-cell communication.
Cell: The Unit of Life
The document discusses the key aspects of cells. It can be summarized as follows:
1. A cell is the smallest and fundamental unit of life, capable of independent function and reproduction.
2. The invention of the microscope allowed Hooke and others to discover cells and establish the cell theory - that cells are the fundamental unit of structure and function for all living things.
3. Cells come in various shapes and sizes depending on their function, and contain specialized internal structures like the nucleus, mitochondria, endoplasmic reticulum, and chloroplasts that allow cells to carry out essential life processes.
UEC Senior 1 Biology 独中高一生物 2.2 microstructure of the cellsYee Sing Ong
Cells are the basic building blocks of life and can exist as single-celled organisms or as parts of multicellular organisms. They come in diverse shapes, sizes and functions but all contain a cell membrane, nucleus for eukaryotic cells, cytoplasm, and some have an additional cell wall. The document provides information on the microstructure of cells and their role as the fundamental unit of life.
This document summarizes the key differences between prokaryotic and eukaryotic cells. Prokaryotic cells do not have a nucleus or membrane-bound organelles, while eukaryotic cells have a nucleus enclosed by a nuclear membrane and various membrane-bound organelles. Some key organelles present in eukaryotic but not prokaryotic cells include mitochondria, chloroplasts, the endoplasmic reticulum and Golgi apparatus. Prokaryotic cells are typically smaller than eukaryotic cells and lack complex internal structures like the cytoskeleton. Their DNA is also not bound in histones and they do not have linear chromosomes with centromeres.
This document describes the key components of plant cells. It notes that plant cells contain a cell wall, cell membrane, protoplasm, cytoplasm, mitochondria, endoplasmic reticulum, golgi complex, plastids, nucleus, ribosomes, vacuoles, and cytoskeleton. Each of these components serves an important function, such as the cell wall providing structure and protection, the mitochondria producing energy, the nucleus regulating the cell, and the vacuoles storing materials. The document concludes that plant cells were first discovered by Schleiden and that they contain many specialized organelles to carry out their functions.
This document summarizes the key differences between plant and animal cells. It states that plant cells have a cell wall and chloroplasts for photosynthesis, while animal cells lack a cell wall. The document outlines several organelles common to both cell types, such as the nucleus, mitochondria, and endoplasmic reticulum. It also notes that plant cells are generally larger than animal cells and have specific roles in transport and photosynthesis.
The plant cell contains several organelles that carry out essential functions. It has a cell wall made of cellulose that provides structure and support. Inside the plasma membrane are organelles including the nucleus that contains DNA, mitochondria and chloroplasts that have their own DNA, the endoplasmic reticulum that transports materials, and vacuoles for storage. Ribosomes produce proteins, and the Golgi apparatus packages cell products. Together these organelles allow the plant cell to grow, carry out photosynthesis and respiration, and transport materials.
This document discusses cell diversity based on origin, size, shape, and other characteristics. It describes two main types of cells: prokaryotic cells which lack a nucleus and organelles, and eukaryotic cells which have a nucleus enclosed by a nuclear membrane and various membrane-bound organelles. Cell size can vary greatly from 0.1 micrometers in some bacteria to meters in some plant and animal cells. Cell shape also varies significantly between cell types and can change based on cell function.
The document summarizes key components and functions of the cell. It describes how the cell membrane controls what enters and exits the cell, such as water, nutrients, and waste. It also mentions that plant, fungi, and most bacteria cells have cell walls that provide structure and protection outside the cell membrane. The document briefly outlines functions of several cellular organelles, including ribosomes that produce proteins, mitochondria that supply energy, and vacuoles that provide storage space for water, food, and enzymes.
The document discusses the key characteristics of life and provides an overview of different types of living organisms. It outlines that all living things share the characteristics of being cellular, metabolic, homeostatic, able to grow and develop, sensitive, able to reproduce, and having heredity. It then describes the hierarchy of biological organization from the cellular to organism level. The rest of the document provides details on the characteristics of different types of organisms, including viruses, prokaryotes, bacteria, eukaryotes, fungi, protists, animals, and plants.
This document provides an overview of cell structure and function. It begins by listing the key objectives, which are to describe plant and animal cell structure, differentiate between the two cell types, and explain the functions of selected cell organelles. It then discusses the components of cells, comparing plant and animal cells and identifying common structures like the cell membrane, nucleus, cytoplasm, and vacuoles. The document explains how cells vary in size but are generally microscopic, and discusses cell functions like diffusion, osmosis, and active transport. It also introduces the concepts of tissues, organs, and organ systems being composed of many cells working together.
This document provides information on different types of cells and organisms across the three domains of life - Bacteria, Archaea, and Eukarya. It describes the key differences between prokaryotic and eukaryotic cells, and notes that prokaryotic cells are more primitive. The domains of Bacteria and Archaea contain organisms with prokaryotic cells, while the domain Eukarya contains eukaryotic cells. Within the domain Eukarya, the kingdom Protista is described which contains a great diversity of single and multi-celled microscopic organisms, including photosynthetic algae and heterotrophic protists that exhibit different modes of movement and nutrition.
Cell (The function and structural unit of life) Class-8thAbhinav Maurya
The document discusses the structure and functions of cells. It begins by summarizing the discovery of cells in the 17th century by Robert Hooke and the development of the cell theory in the 19th century. It then defines the cell as the basic unit of life and discusses variations in cell number, shape, and size between organisms. The main parts of the cell are then described in detail, including the cell membrane, cytoplasm, nucleus, and various organelles. Key differences between plant and animal cells are also highlighted.
Plant and animal cells differ in several key ways. Plant cells are typically rectangular in shape and larger than animal cells, which are usually spherical and smaller. Plant cells have a thick cell wall made of cellulose and hemicellulose, while animal cells only have a thin cell membrane. A prominent vacuole is present in plant cells but small and temporary in animal cells. Plastids are found only in plant cells, while centrosomes are present in animal cells to aid cell division. Mitochondria are more numerous in animal cells compared to plant cells. Plant cells can synthesize all amino acids whereas animal cells can only synthesize some kinds. Cell division occurs via cell plate in plants but by furrow in animals.
This document provides information about plant tissues. It discusses the two main types of plant tissues - meristems and permanent tissues. Meristems are tissues with cell division abilities and include apical, lateral, and intercalary meristems. Permanent tissues do not divide and include simple tissues like parenchyma, collenchyma, and sclerenchyma, as well as complex tissues like xylem and phloem. It also describes the functions and characteristics of epidermis, cork, and other specific plant tissue types. Various activities provide examples and questions to test understanding of plant tissue organization and functions.
Plant tissues are divided into meristematic and permanent tissues. Meristematic tissues include apical and vascular cambium, which are responsible for growth. Apical meristem promotes primary growth at tips while vascular cambium promotes secondary growth by increasing diameter. Permanent tissues derive from meristematic tissues and include simple tissues like parenchyma, collenchyma and sclerenchyma, as well as complex tissues like xylem and phloem. Xylem transports water and minerals upwards while phloem transports food materials horizontally. Transpiration creates a pull that drives the movement of water through xylem vessels via capillary action from roots to shoots.
The document provides information about plant and animal cells. It defines cells as the basic unit of living things and notes that plants and animals are made of cells. The key differences between plant and animal cells are that plant cells contain a cell wall and chloroplasts, which allow them to perform photosynthesis, while animal cells do not have these structures. Both plant and animal cells share other common cellular components including the cell membrane, cytoplasm, mitochondria, nucleus, and vacuoles.
Cells are the basic unit of structure and function of all living things. They contain organelles that allow specific functions like protein production, energy generation, waste digestion, and more. The cell membrane controls what enters and leaves the cell and provides structure and protection. Plant and animal cells differ in their additional structures - plant cells have cell walls and chloroplasts, while animal cells do not have cell walls.
Prokaryotic and Eukaryotic Algal cell structuregkumarimahesh
The document summarizes the cell structure of prokaryotic and eukaryotic algal cells. Prokaryotic cells like cyanobacteria have an outer cellular covering including a mucilaginous sheath and cell wall, as well as a cytoplasm differentiated into a pigmented chromoplasm and central colorless centroplasm containing DNA. Eukaryotic algal cells have a cell wall, plasma lemma, and protoplast containing organelles like a chloroplast, mitochondria, and flagella. The chloroplast contains thylakoids and pyrenoids and the cell has structures like an eyespot.
2.1 type of cells UEC Senior 1 Biology 独中高一生物 Yee Sing Ong
This document discusses the differences between prokaryotic and eukaryotic cells. Prokaryotic cells, such as bacteria and archaea, lack a nucleus and organelles. They have simpler DNA not organized into chromosomes and smaller ribosomes. Eukaryotic cells, which include plants, animals, fungi and protists, have a nucleus enclosed in a membrane as well as other membrane-bound organelles. They have larger DNA-protein complexes called chromosomes and larger ribosomes. The document provides examples of different types of prokaryotic and eukaryotic cells and outlines their key similarities and differences.
In this power point presentation Viewer will be able to know about the Plant Cell Constituents. How plants cells Composed with different organelles. What are the functions they have during the growth of particular plant. Plant cells are primary unit of the plant body and from here only we get medicinal value chemical constituents.
Portion Covered:
1. Plant Cells
2. Plant Cell Diagram
3. Plant cell Structure
4. Plant cell type
5. Plant cell Functions
This document defines cell modification and describes the three main types: apical, basal, and lateral modifications. It provides examples of each type of modification and their functions. Apical modifications include cilia, flagella, microvilli, and pseudopods, which increase surface area. Basal modifications are hemidesmosomes, which anchor the cell. Lateral modifications are tight junctions, adhering junctions, and gap junctions, which regulate movement between cells and allow cell-to-cell communication.
Cell: The Unit of Life
The document discusses the key aspects of cells. It can be summarized as follows:
1. A cell is the smallest and fundamental unit of life, capable of independent function and reproduction.
2. The invention of the microscope allowed Hooke and others to discover cells and establish the cell theory - that cells are the fundamental unit of structure and function for all living things.
3. Cells come in various shapes and sizes depending on their function, and contain specialized internal structures like the nucleus, mitochondria, endoplasmic reticulum, and chloroplasts that allow cells to carry out essential life processes.
UEC Senior 1 Biology 独中高一生物 2.2 microstructure of the cellsYee Sing Ong
Cells are the basic building blocks of life and can exist as single-celled organisms or as parts of multicellular organisms. They come in diverse shapes, sizes and functions but all contain a cell membrane, nucleus for eukaryotic cells, cytoplasm, and some have an additional cell wall. The document provides information on the microstructure of cells and their role as the fundamental unit of life.
This document summarizes the key differences between prokaryotic and eukaryotic cells. Prokaryotic cells do not have a nucleus or membrane-bound organelles, while eukaryotic cells have a nucleus enclosed by a nuclear membrane and various membrane-bound organelles. Some key organelles present in eukaryotic but not prokaryotic cells include mitochondria, chloroplasts, the endoplasmic reticulum and Golgi apparatus. Prokaryotic cells are typically smaller than eukaryotic cells and lack complex internal structures like the cytoskeleton. Their DNA is also not bound in histones and they do not have linear chromosomes with centromeres.
This document describes the key components of plant cells. It notes that plant cells contain a cell wall, cell membrane, protoplasm, cytoplasm, mitochondria, endoplasmic reticulum, golgi complex, plastids, nucleus, ribosomes, vacuoles, and cytoskeleton. Each of these components serves an important function, such as the cell wall providing structure and protection, the mitochondria producing energy, the nucleus regulating the cell, and the vacuoles storing materials. The document concludes that plant cells were first discovered by Schleiden and that they contain many specialized organelles to carry out their functions.
This document summarizes the key differences between plant and animal cells. It states that plant cells have a cell wall and chloroplasts for photosynthesis, while animal cells lack a cell wall. The document outlines several organelles common to both cell types, such as the nucleus, mitochondria, and endoplasmic reticulum. It also notes that plant cells are generally larger than animal cells and have specific roles in transport and photosynthesis.
The plant cell contains several organelles that carry out essential functions. It has a cell wall made of cellulose that provides structure and support. Inside the plasma membrane are organelles including the nucleus that contains DNA, mitochondria and chloroplasts that have their own DNA, the endoplasmic reticulum that transports materials, and vacuoles for storage. Ribosomes produce proteins, and the Golgi apparatus packages cell products. Together these organelles allow the plant cell to grow, carry out photosynthesis and respiration, and transport materials.
This document discusses cell diversity based on origin, size, shape, and other characteristics. It describes two main types of cells: prokaryotic cells which lack a nucleus and organelles, and eukaryotic cells which have a nucleus enclosed by a nuclear membrane and various membrane-bound organelles. Cell size can vary greatly from 0.1 micrometers in some bacteria to meters in some plant and animal cells. Cell shape also varies significantly between cell types and can change based on cell function.
The document summarizes key components and functions of the cell. It describes how the cell membrane controls what enters and exits the cell, such as water, nutrients, and waste. It also mentions that plant, fungi, and most bacteria cells have cell walls that provide structure and protection outside the cell membrane. The document briefly outlines functions of several cellular organelles, including ribosomes that produce proteins, mitochondria that supply energy, and vacuoles that provide storage space for water, food, and enzymes.
The document discusses the key characteristics of life and provides an overview of different types of living organisms. It outlines that all living things share the characteristics of being cellular, metabolic, homeostatic, able to grow and develop, sensitive, able to reproduce, and having heredity. It then describes the hierarchy of biological organization from the cellular to organism level. The rest of the document provides details on the characteristics of different types of organisms, including viruses, prokaryotes, bacteria, eukaryotes, fungi, protists, animals, and plants.
This document provides an overview of cell structure and function. It begins by listing the key objectives, which are to describe plant and animal cell structure, differentiate between the two cell types, and explain the functions of selected cell organelles. It then discusses the components of cells, comparing plant and animal cells and identifying common structures like the cell membrane, nucleus, cytoplasm, and vacuoles. The document explains how cells vary in size but are generally microscopic, and discusses cell functions like diffusion, osmosis, and active transport. It also introduces the concepts of tissues, organs, and organ systems being composed of many cells working together.
This document provides information on different types of cells and organisms across the three domains of life - Bacteria, Archaea, and Eukarya. It describes the key differences between prokaryotic and eukaryotic cells, and notes that prokaryotic cells are more primitive. The domains of Bacteria and Archaea contain organisms with prokaryotic cells, while the domain Eukarya contains eukaryotic cells. Within the domain Eukarya, the kingdom Protista is described which contains a great diversity of single and multi-celled microscopic organisms, including photosynthetic algae and heterotrophic protists that exhibit different modes of movement and nutrition.
Cell (The function and structural unit of life) Class-8thAbhinav Maurya
The document discusses the structure and functions of cells. It begins by summarizing the discovery of cells in the 17th century by Robert Hooke and the development of the cell theory in the 19th century. It then defines the cell as the basic unit of life and discusses variations in cell number, shape, and size between organisms. The main parts of the cell are then described in detail, including the cell membrane, cytoplasm, nucleus, and various organelles. Key differences between plant and animal cells are also highlighted.
Plant and animal cells differ in several key ways. Plant cells are typically rectangular in shape and larger than animal cells, which are usually spherical and smaller. Plant cells have a thick cell wall made of cellulose and hemicellulose, while animal cells only have a thin cell membrane. A prominent vacuole is present in plant cells but small and temporary in animal cells. Plastids are found only in plant cells, while centrosomes are present in animal cells to aid cell division. Mitochondria are more numerous in animal cells compared to plant cells. Plant cells can synthesize all amino acids whereas animal cells can only synthesize some kinds. Cell division occurs via cell plate in plants but by furrow in animals.
This document provides information about plant tissues. It discusses the two main types of plant tissues - meristems and permanent tissues. Meristems are tissues with cell division abilities and include apical, lateral, and intercalary meristems. Permanent tissues do not divide and include simple tissues like parenchyma, collenchyma, and sclerenchyma, as well as complex tissues like xylem and phloem. It also describes the functions and characteristics of epidermis, cork, and other specific plant tissue types. Various activities provide examples and questions to test understanding of plant tissue organization and functions.
Plant tissues are divided into meristematic and permanent tissues. Meristematic tissues include apical and vascular cambium, which are responsible for growth. Apical meristem promotes primary growth at tips while vascular cambium promotes secondary growth by increasing diameter. Permanent tissues derive from meristematic tissues and include simple tissues like parenchyma, collenchyma and sclerenchyma, as well as complex tissues like xylem and phloem. Xylem transports water and minerals upwards while phloem transports food materials horizontally. Transpiration creates a pull that drives the movement of water through xylem vessels via capillary action from roots to shoots.
The document provides information on the anatomy and tissues of flowering plants. It discusses the basic plant tissues like meristematic tissues, permanent tissues, simple tissues and complex tissues. It describes the primary tissues - parenchyma, collenchyma and sclerenchyma. It also elaborates on the complex vascular tissues - xylem and phloem. Furthermore, it discusses the three tissue systems - epidermal, ground and vascular tissue systems. Lastly, it compares the anatomical differences between monocot and dicot plants in roots, stems and leaves.
Plant anatomy is the study of the internal structures of plant organs. The three main plant structures are roots, stems, and leaves. Roots absorb water and nutrients and anchor the plant. Stems provide structure and transport nutrients. Leaves are the main photosynthetic organs and sites of gas exchange. Internally, plant organs contain tissues including epidermis, ground tissues, and vascular bundles. The epidermis protects the plant while vascular bundles transport water and nutrients. Ground tissues provide structure and store nutrients. Roots, stems, and leaves show variations between monocots and dicots in their structures.
Cell specialization allows multicellular organisms to grow larger while dividing labor across specialized cell types and tissues. Tissues are groups of similar cells that work together to perform a common function. There are four main types of plant tissues - meristematic tissue which facilitates growth, permanent tissues including parenchyma for storage and transport, collenchyma for support and flexibility, and sclerenchyma for protection and strength. Animal tissues also specialize, with connective tissue binding other tissues, muscular tissue enabling movement, nervous tissue coordinating signals, and epithelial tissue covering and protecting organs.
Plant organs include leaves, stems, and roots. Leaves contain chloroplasts for photosynthesis and have an upper and lower epidermis, palisade mesophyll and spongy mesophyll tissue layers. Stems have vascular bundles containing xylem and phloem tissues. Roots absorb water and minerals and have root hairs, epidermis, cortex and stele tissues. Plant tissues include dermal tissue, ground tissue, and vascular tissue which transport water, minerals and sugars throughout the plant.
This document provides information on plant tissues and the differences between monocot and dicot plants. It begins with an introduction to plant tissues, including meristematic and permanent tissues. It then describes the key tissues like epidermis, parenchyma, collenchyma, sclerenchyma and vascular tissues. Next, it highlights the differences between monocots and dicots with regards to their seed leaves, vascular bundles, flower parts, mature leaves and roots. It also provides microscopic images of monocot and dicot structures. The document concludes with information about practical training on plant identification which includes a list of drugs and their powder and tissue section microscopic analysis.
1) Meristematic tissue contains undifferentiated cells that actively divide throughout a plant's life to form specialized structures like leaves, flowers, roots and shoots.
2) The tissue is usually found at root and shoot tips and helps increase plant length and girth.
3) Meristematic tissue is classified based on origin, development stage, position and function - including apical, intercalary and lateral meristems that contribute to height, internodal length and thickness.
The document discusses plant tissues and types of plant tissues. There are three main types of plant tissues: dermal tissue (epidermis), ground tissue (parenchyma, collenchyma, sclerenchyma), and vascular tissue (xylem and phloem). Meristematic tissue consists of actively dividing cells and is responsible for growth in plants. Meristematic tissue differentiates into permanent tissues, which include simple tissues like parenchyma, collenchyma, and sclerenchyma, as well as complex vascular tissues.
The document discusses plant tissues and meristems. It describes the three main types of meristems - apical, lateral, and intercalary meristems - and their roles in primary and secondary growth. It also outlines the simple permanent tissues of parenchyma, collenchyma, sclerenchyma, and epidermis. Complex vascular and dermal tissues like xylem, phloem, and periderm are also summarized. Secretory structures are briefly mentioned. Diagrams accompany the descriptions of tissue types and organization.
The document discusses the different types of plant tissues. There are three main types of plant tissues: dermal tissue (epidermis), ground tissue (parenchyma, collenchyma, sclerenchyma), and vascular tissue (xylem and phloem). Xylem tissue transports water and minerals throughout the plant. Phloem tissue transports sugars and nutrients. Meristematic tissue consists of actively dividing cells and is responsible for growth in plants. As cells differentiate, they take on specialized roles and functions as part of the permanent tissues that make up the main tissue systems in plants.
Plant tissues can be divided into 3 main categories - dermal, vascular and ground tissues. There are three types of plant tissues - meristematic, permanent and complex permanent tissues. Meristematic tissues are found in apical, lateral and intercalary meristems and allow for plant growth. Permanent tissues such as parenchyma, collenchyma and sclerenchyma do not divide. Complex permanent tissues include xylem and phloem which transport water and nutrients. Plant tissues have many economic uses including food, furniture, clothing fibers, horticulture, and conservation of endangered species.
Plant tissues can be divided into two main types - meristematic and permanent tissues. Meristematic tissues are actively dividing and responsible for growth. They are found in apical, lateral, and intercalary meristems. Permanent tissues have stopped dividing and perform specific functions. These include dermal tissues like epidermis and periderm, ground tissues like parenchyma and sclerenchyma, and vascular tissues for transport, like xylem and phloem. Xylem transports water and nutrients upward and is composed of tracheids and vessel elements. Phloem transports organic nutrients in all directions and contains sieve tube elements.
The document discusses plant anatomy and the different types of tissues that make up plant structures. It describes three main tissue systems - dermal tissue, ground tissue, and vascular tissue. Dermal tissue provides protection, ground tissue includes parenchyma cells, and vascular tissue contains xylem and phloem conducting elements. Tissues are further divided into meristematic and permanent tissues. Meristematic tissues include apical and lateral meristems that allow for growth, while permanent tissues like parenchyma, collenchyma, sclerenchyma, xylem and phloem have specialized functions.
Tissues are groups of cells that work together to perform specific functions. There are four main types of animal tissues - epithelial, muscular, connective, and nervous tissue. Epithelial tissue forms protective layers like skin and lines body cavities. It consists of closely packed cells with little extracellular space. Plant tissues include meristematic tissue for growth and permanent tissues like parenchyma, collenchyma, and sclerenchyma. Vascular tissues xylem and phloem transport water and nutrients throughout the plant. Tissues are made of groups of cells that carry out important roles in living organisms.
This document summarizes the different types of plant tissues. It explains that plants are made of cells organized into tissues with specific functions. There are two main types of tissues - permanent tissues which include dermal, ground, and vascular tissues that provide structure and transport; and meristematic tissues which are dividing cells that produce new cells and allow for plant growth. The document provides details on the characteristics and roles of each type of tissue.
This document discusses plant tissues and their classification. There are two main types of plant tissues: meristematic and permanent tissues. Meristematic tissues are dividing tissues found in regions of growth called meristems, including apical, lateral, and intercalary meristems. Permanent tissues have stopped dividing and take on specialized functions, including simple tissues like epidermis, parenchyma, chlorenchyma, and sclerenchyma, as well as complex vascular tissues like xylem and phloem which transport water and nutrients throughout the plant.
This document discusses the characteristics of vascular plants, specifically angiosperms. It describes that angiosperms have enclosed seeds protected inside a fruit. They have flowers, vascular tissue, and alternate between generations. Angiosperms are divided into monocots and dicots. Monocots have one cotyledon and parallel veins, while dicots have two cotyledons and branching veins. The document outlines the structures and functions of floral parts and how angiosperms reproduce through a process called double fertilization.
Meristematic tissue is a plant tissue that is undifferentiated and can divide to form other tissues. It is found in three main regions: the apical meristem at the tips of stems and roots, the intercalary meristem at the bases of leaves and stems, and the lateral meristem or cambium responsible for increasing the girth of stems and roots. Permanent tissues are differentiated tissues that do not divide, such as parenchyma, collenchyma and sclerenchyma. Epithelial tissue forms protective layers in animals, such as the skin and lining of organs, while connective tissue binds and supports other tissues.
This PPT contains a birds' eye view of the basic internal organization of the plant body comprising of tissue networks along with tissue systems to perform diverse functions for plants survival even in stress condition.
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2. Pre-reading Quiz
• Which of the following is not a type of plant tissue?
A. Epithelial tissue
B. Epidermis tissue
C. Shoot meristem tissue
D. Vascular cambium tissue
3. Why do we study plant
tissue?
• Plants have impressive diversity,
specialized structure, and biochemical
attributes.
• The histology of plant structure allows
us to understand how plants acclimate
适应 to the environment and what are
the factors that determine variations in
plant form follow.
• Types and organizations of tissues can
provide insight into speciation and the
phylogeny of plant groups.
4. Common themes in the
structure of plants
• Physical forces do impose limits on cell
sizes and shapes, hence there are only a
limited type of tissue though they may
looked different.
• Plant needs tissues to support as they
grow stems, branches with leaves or erect
reproductive structures with flowers.
• Most plants require tissues for transport,
to move water and nutrients from one
plant part to another.
Xylem cell types.
5. Types of plant tissue
• Plant tissues can be divided into
five main types based on their
morphological structure and
physiological functions:
• meristematic tissue
• protective tissue
• parenchyma tissue
• mechanical tissue
• conductive tissue
7. Meristematic tissue 分生组织
• Tissue that contains undifferentiated meristematic
cells分生细胞.
• Meristematic cells can divide rapidly through mitosis
有丝分裂 and they are indeterminate cells that are
not specialized yet.
• Meristem cells are small, thin-walled, closely
arranged, have relatively large nucleus, dense
cytoplasm and generally no vacuoles.
• Meristem are found in zones of the plant where
growth can take place.
Root meristem of onion.
8. Types of meristem
Based on the
location of
meristematic tissues
in plants, it can be
divided into:
• Primary (apical)
meristem 初生分
生组织/顶端分生
组织
• Secondary (lateral)
meristem 次生分
生组织
9. Primary and secondary growth
The increase in the
length of the shoot and
the roots
The increase in the
thickness or the girth of
the plant
Primary Growth
Secondary Growth
10. Primary (apical) meristem
• It is located at the tip of the roots and the shoots of plants.
• The root apical meristems give rise to future roots.
• The shoot apical meristems give rise to flower, fruit, leaf and stem.
11. Secondary (lateral) meristem
• It is located at the lateral side of roots and
stems and occurs as cylinders in older parts
of stem.
• It causes lateral growth (increase in
diameter)
• It includes the vascular cambium 维管束形
成层 and cork cambium 木栓形成层.
• Vascular cambium produces secondary
xylem 次生木质部 and secondary phloem
次生韧皮部.
• Cork cambium forms new layers of
protective tissue (periderm) on top of the
thicken surfaces of roots and shoots.
• Not all plants undergoes secondary growth.
16. Protective tissue
• It covers the outermost surface of plant
body for protection.
• Its cells are closely arranged, flattened
and irregular in shape, lack of
chloroplast and with thick cell wall.
• Its function is to reduce the loss of
water through transpiration, to prevent
invasion of diseases caused by
pathogens and mechanical injury etc.
• Examples: epidermal tissue, periderm
(form by the cork cambium) and cork.
Root hair is an extension of root
epidermal cells.
Periderm (yellow) of a stem
under light microscope (10x).
保护组织
17. Epidermal tissue
Top: The epidermal tissue on the abaxial side of the leaf:
epidermal cells, guard cells, subsidiary cells, and epidermal
hairs (trichomes 毛茸).
Left: Root hair as an extension of root epidermal cell/
• Greek ἐπιδερμίς, meaning “over-skin”
• A single layer of cells that covers the
leaves, flowers, roots and stems.
• Functions:
• Forms a boundary between the plant and
the external environment.
• Protects against water loss
• Regulates gas exchange
• Secretes metabolic compounds
• Absorbs water and mineral nutrients (roots)
trichomes
Guard cells around
stroma & pavement cells
表皮
18. Periderm and cork
• Periderm 周皮 includes cork 木栓
层, the cork cambium木栓形成层
(and the phelloderm 栓内层).
• Periderm is only found in plants
with secondary growth.
• Cork is an external, secondary
tissue that is impermeable to
water and gases.
• Function of cork:
• protects the stem against water loss
• Protects the invasion of insects into
the stem
• prevents infections by bacteria and
fungal spores
19. Quiz
• Which of the following is not a kind of epidermal cell or part of an
epidermal cell?
A) trichome
B) root hair
C) guard cell
D) cork
20. Conclusion
• Protective tissue covers the outermost surface of plant body for
protection.
• Its cells are closely arranged, flattened and irregular in shape, lack of
chloroplast and with thick cell wall.
• Its functions are to reduce the loss of water through transpiration, to
prevent invasion of diseases caused by pathogens and mechanical
injury etc.
• Epidermal tissue is found in all parts of the plant cells.
• Periderm, differentiated from the cork cambium, replace epidermal
tissue in plants with secondary growth.
22. Supporting tissue or
Packing tissue
• Parenchyma is the least specialised cell
types found in all organs of a plant.
• Greek word para meaning "beside",
chyma meaning "in filling
• Its cells are large, with relatively thin
primary cell walls and a large central
vacuole.
• The cells are loosely packed together
with large intercellular air spaces to allow
exchange of gases.
• Parenchyma cells can be found in the
ground tissue of pith and epidermal in
stems and roots, leaves, flowers and
many fruits and seeds.
薄壁組織
23. Functions of parenchyma tissue
• Wound repair and the potential for
renewed meristematic activity
• Photosynthesis (mesophyll
cells/chlorenchyma cells = parenchyma
cells with chloroplasts)
• The exchange of gases (guard cells)
• Storage of starch, protein, fats, oils and
water in roots, tubers (e.g. potatoes), seed
endosperm (e.g. cereals) and cotyledons
(e.g. pulses and peanuts)
• Secretion (e.g. the parenchyma cells lining
the inside of resin ducts)
• Aeration that provides buoyancy and helps
aquatic plants in floating (aerenchyma)
26. Collenchyma tissue
• Collenchyma tissue consists of living
elongated cells with irregularly
thickened walls.
• Collenchyma cells have only a thick
primary cell wall made up of cellulose
and pectin, with thickenings at the
corners of the cells.
• They provide structural support,
particularly in growing shoots and
leaves, and may be the main
supportive tissue for some herbaceous
plants.
厚角組織
27. Sclerenchyma tissue
• Sclerenchyma cells are the principal
supporting cells in plant tissues that have
ceased elongation.
• Sclerenchyma has thick secondary cell walls
which are completely lignified 木质化.
• The cell wall is impermeable to water, solutes
and gases, although pits are present in the cell
walls.
• When the cells are maturing, lignin 木质素 is
deposited gradually on the walls.
• At maturity, they contain no living protoplast,
i.e. they are dead at maturity.
• Sclerenchyma can be divided into fibres and
sclereids.
Lignin in sclerenchyma can be stained red with
safranin or phloroglucinol-hydrochloric acid.
厚壁組織
28. Fibre
• Fibers or bast are generally long,
slender, usually occurring in strands or
bundles.
• Fibres are mainly found in the roots
and the stems of plants.
• For example in stems of flax 亚麻,
hemp 麻 and jute 黄麻.
纖維細胞
Flax, hemp, and jute
29. Sclereids
• Sclereids are often found in the fruits
and the seeds of plants (though they
may be found in leaves as well).
• These are relatively short and generally
have a shape of a star.
• Sclereids protect other cells.
• For example, sclereids can be found as
white and hard granules in the pericarp
of pear, cores of apples.
石细胞
32. Quiz
• Plants grow throughout their entire lives because of ______ that
continues to divide.
A) vascular tissue
B) dermal tissue
C) meristem tissue
D) ground tissue
33. Quiz
• Which of the following cells protect the inner body parts and prevent
the plant from drying out?
A) epidermal cells
B) parenchymal cell
C) sclerenchymal cell
D) sieve-tube cell
E) tracheid cell
34. Quiz
• Which of the following cells are relatively unspecialized and
correspond best to the generalized plant cell?
A) epidermal cells
B) parenchymal cell
C) sclerenchymal cell
D) sieve-tube cell
E) tracheid cell
36. Conductive tissue
• Conductive tissue is also known
as the vascular tissue.
• It is a compound tissue which is
composed of several types of
cells.
• It can be divided into xylem and
phloem.
Cross-section of a leaf.
输导组织
维管组织
木质部韧皮部
37. Xylem
• derived from the Greek word ξύλον (xylon)
"wood"
• Xylem transports water and inorganic salts from
the roots to other parts of the plants.
• The movement of water is unidirectional.
• Xylem consists of three different types of cells:
xylem parenchyma cells and xylem fiber cells, and
the tracheary elements (TE).
• The TE are completely dead at maturity, and act
like pipes.
• The TE have a thick, strengthened cellulose cell
wall with a hollow lumen.
• There are two types of tracheary elements: vessel
elements and tracheids.
• Tracheids are longer.
• Vessel elements are shorter, and are connected
together into long tubes that are called vessels.
• Parenchyma cells store water, mineral nutrients
and carbohydrates, and respond to wounding.
• Fibers provide structural support.
38. Phloem
• derived from the Greek word φλοιός
(phloios) "bark".
• Phloem transport organic nutrients made
during photosynthesis (photosynthate) to all
parts of the plant where needed.
• The movement of photosynthate can be
bidirectional, but mostly are from source
tissues (eg. mesophyll cells) to sink tissues
(eg. non-photosynthetic cells).
• Phloem is composed of several cell types
including sclerenchyma, parenchyma, sieve
elements.
• Sieve element conducts the photosynthate.
• Parenchyma cells carried out metabolic
functions helps transfer materials between
phloem and other tissues.
• Sclerenchyma such as fibres and sclereids
provide structural support.
39.
40. Quiz
• Xylem and phloem belong to the ______ tissue system.
A) dermal
B) ground
C) vascular
41. Quiz
• Which of the following cells are hollow and nonliving at maturity?
A) epidermal cell
B) parenchymal cell
C) tracheid
D) sieve-tube cell
E) companion cell