The document discusses the cell cycle and cell reproduction. It describes the main stages as interphase, where the cell grows and prepares for division, and the M phase where the nucleus and cell divide. Interphase includes the G1, S, and G2 phases where the cell makes proteins, organelles and replicates DNA. The M phase consists of mitosis, where the nucleus divides, and cytokinesis, where the cell splits into two. Mitosis is further broken down into the prophase, metaphase, anaphase and telophase stages where the chromosomes align and separate. Cytokinesis differs in animal and plant cells in how the cell membrane pinches or a cell plate forms to divide the cell. The result of
This document provides information about cell division through mitosis and meiosis. It discusses the three main types of cell division - binary fission in prokaryotes, mitosis in eukaryotes for growth and repair, and meiosis in eukaryotes for sexual reproduction. The stages of mitosis (prophase, metaphase, anaphase, telophase) and meiosis I and II are described in detail. The cell cycle is also summarized, including the interphase and mitotic phases.
The ability of organisms to produce more of their own kind is the one characteristic that best distinguishes living things from nonliving matter. This unique capacity to procreate, like all biological functions, has a cellular basis. The continuity of life is based on the reproduction of cells, or cell division. Cell division plays several important roles which are giving rise to a new organism, enabling development, renewing and repairing and also replacing damaged tissue is multicellular organisms.
توانایی موجودات زنده در تولید بیشتر از نوع خود یکی از ویژگیهایی است که موجودات زنده را از مواد غیر زنده به بهترین وجه متمایز می کند. این ظرفیت منحصر به فرد برای تولید مثل، مانند همه عملکردهای بیولوژیک، دارای پایه سلولی است. تداوم زندگی براساس تولید مثل سلولها یا تقسیم سلولی است. تقسیم سلولی چندین نقش مهم را ایفا میکند که نه تنها باعث ایجاد یک ارگانیسم جدید میشود، همچنین امکان رشد، تجدید و ترمیم و همچنین جایگزینی بافت آسیب دیده موجودات چند سلولی را نیز فراهم می کند.
Cell division occurs through mitosis and meiosis. Mitosis produces two identical daughter cells and is important for growth and repair. It has four phases: prophase, metaphase, anaphase and telophase. Meiosis reduces the chromosome number by half and produces genetic variation important for sexual reproduction. Meiosis has two divisions and involves homologous chromosome pairing, crossing over and separation into four haploid cells. The key difference is that mitosis maintains ploidy levels while meiosis reduces them, resulting in genetic variation.
Cell division occurs through mitosis and meiosis. Mitosis produces two identical daughter cells and is used for cell growth and repair. Meiosis produces four haploid cells through two cell divisions and is involved in sexual reproduction to create sex cells. The key differences are that mitosis maintains chromosome number while meiosis reduces it, and meiosis involves homologous chromosome pairing and genetic recombination during prophase I.
This document provides an overview of cell division, specifically mitosis and meiosis. It begins with definitions of the key types of cell division - amitosis, mitosis, and meiosis. It then covers the stages and processes of mitosis, including interphase and the four stages of mitosis (prophase, metaphase, anaphase, telophase). The document also discusses the cell cycle and DNA content during cell division. Meiosis is then introduced, focusing on its production of gametes and halving of chromosome number compared to mitosis.
Cells divide through the cell cycle in order to grow, replace old cells, and make organisms grow. The cell cycle involves cell growth, DNA replication, and cell division through mitosis or meiosis. Mitosis produces two identical daughter cells through the phases of interphase, prophase, metaphase, anaphase, telophase, and cytokinesis. Meiosis reduces the chromosome number by half and produces genetically distinct gametes for sexual reproduction.
The document discusses the cell cycle and cell reproduction. It describes the main stages as interphase, where the cell grows and prepares for division, and the M phase where the nucleus and cell divide. Interphase includes the G1, S, and G2 phases where the cell makes proteins, organelles and replicates DNA. The M phase consists of mitosis, where the nucleus divides, and cytokinesis, where the cell splits into two. Mitosis is further broken down into the prophase, metaphase, anaphase and telophase stages where the chromosomes align and separate. Cytokinesis differs in animal and plant cells in how the cell membrane pinches or a cell plate forms to divide the cell. The result of
This document provides information about cell division through mitosis and meiosis. It discusses the three main types of cell division - binary fission in prokaryotes, mitosis in eukaryotes for growth and repair, and meiosis in eukaryotes for sexual reproduction. The stages of mitosis (prophase, metaphase, anaphase, telophase) and meiosis I and II are described in detail. The cell cycle is also summarized, including the interphase and mitotic phases.
The ability of organisms to produce more of their own kind is the one characteristic that best distinguishes living things from nonliving matter. This unique capacity to procreate, like all biological functions, has a cellular basis. The continuity of life is based on the reproduction of cells, or cell division. Cell division plays several important roles which are giving rise to a new organism, enabling development, renewing and repairing and also replacing damaged tissue is multicellular organisms.
توانایی موجودات زنده در تولید بیشتر از نوع خود یکی از ویژگیهایی است که موجودات زنده را از مواد غیر زنده به بهترین وجه متمایز می کند. این ظرفیت منحصر به فرد برای تولید مثل، مانند همه عملکردهای بیولوژیک، دارای پایه سلولی است. تداوم زندگی براساس تولید مثل سلولها یا تقسیم سلولی است. تقسیم سلولی چندین نقش مهم را ایفا میکند که نه تنها باعث ایجاد یک ارگانیسم جدید میشود، همچنین امکان رشد، تجدید و ترمیم و همچنین جایگزینی بافت آسیب دیده موجودات چند سلولی را نیز فراهم می کند.
Cell division occurs through mitosis and meiosis. Mitosis produces two identical daughter cells and is important for growth and repair. It has four phases: prophase, metaphase, anaphase and telophase. Meiosis reduces the chromosome number by half and produces genetic variation important for sexual reproduction. Meiosis has two divisions and involves homologous chromosome pairing, crossing over and separation into four haploid cells. The key difference is that mitosis maintains ploidy levels while meiosis reduces them, resulting in genetic variation.
Cell division occurs through mitosis and meiosis. Mitosis produces two identical daughter cells and is used for cell growth and repair. Meiosis produces four haploid cells through two cell divisions and is involved in sexual reproduction to create sex cells. The key differences are that mitosis maintains chromosome number while meiosis reduces it, and meiosis involves homologous chromosome pairing and genetic recombination during prophase I.
This document provides an overview of cell division, specifically mitosis and meiosis. It begins with definitions of the key types of cell division - amitosis, mitosis, and meiosis. It then covers the stages and processes of mitosis, including interphase and the four stages of mitosis (prophase, metaphase, anaphase, telophase). The document also discusses the cell cycle and DNA content during cell division. Meiosis is then introduced, focusing on its production of gametes and halving of chromosome number compared to mitosis.
Cells divide through the cell cycle in order to grow, replace old cells, and make organisms grow. The cell cycle involves cell growth, DNA replication, and cell division through mitosis or meiosis. Mitosis produces two identical daughter cells through the phases of interphase, prophase, metaphase, anaphase, telophase, and cytokinesis. Meiosis reduces the chromosome number by half and produces genetically distinct gametes for sexual reproduction.
The document summarizes the processes of mitosis and meiosis in eukaryotic cells. It describes the stages of the cell cycle including interphase and mitosis. Mitosis is divided into prophase, metaphase, anaphase and telophase where chromosomes are aligned and separated. Meiosis produces gametes through two cell divisions and a single DNA replication. This reduces the chromosome number by half to maintain genetic diversity between generations. Crossing over and random chromosome segregation in meiosis lead to genetic variation important for evolution.
CELL CYCLE , MITOSIS ,MEIOSIS AND CELL REGULATIONLIFE SCIENCES
The document discusses the cell cycle and its regulation. It describes the main phases of the cell cycle including interphase with G1, S, and G2 phases, and mitosis. It also covers meiosis and the key differences between mitosis and meiosis. Cell cycle checkpoints are mentioned which allow the cell cycle to be halted at certain points if conditions are not favorable for progression.
Cytokinesis involves the division of the cytoplasm following mitosis to form two daughter cells. It begins before nuclear division is complete. In animal cells, actin filaments contract to form a cleavage furrow that deepens and separates the cell into two daughters. In plant cells, membrane vesicles gather at the equator and fuse to form a cell plate, which grows outward and fuses with the parent cell's membrane to produce new cell walls.
The cell cycle is the series of growth and division steps that cells undergo. It includes interphase, where the cell grows and duplicates its DNA, and mitosis, where the cell separates its DNA and divides into two daughter cells. Interphase consists of G1 phase, S phase where DNA replicates, and G2 phase. Mitosis then occurs in four phases - prophase, metaphase, anaphase and telophase - where the duplicated chromosomes separate and the cell divides. Cytokinesis then divides the cytoplasm, forming two new identical daughter cells to complete the cell cycle.
This document defines key terms related to cell division and DNA, describes the main stages of the cell cycle and mitosis, and explains the significance of mitosis. It states that mitosis results in two daughter cells that are genetically identical to the parent cell, ensuring genetic stability. It occurs in two phases: nuclear division and cytoplasm division. The four stages of mitosis are prophase, metaphase, anaphase and telophase. Cytokinesis then divides the cytoplasm through cleavage or cell plate formation in animal and plant cells respectively.
This document defines key terms related to cell division, DNA, chromosomes, and genetics. It describes the two main types of cell division - mitosis and meiosis. Mitosis is defined as nuclear division that results in daughter cells with the same number of chromosomes as the parent cell, while meiosis results in daughter cells with half the number of chromosomes. The stages of the cell cycle are explained as G1, S phase, G2, and mitosis. The stages of mitosis and differences between plant and animal cell cytokinesis are summarized. Significance of mitosis includes genetic stability, growth, cell replacement, regeneration, and asexual reproduction.
This document provides an overview of cell division through mitosis and meiosis. It explains that all living things are made of cells, and cells must divide for organisms to grow and replace old cells. The cell cycle is described, including the main stages of interphase, mitosis, and cytokinesis. Interphase consists of G1, S, and G2 phases where the cell grows and duplicates its DNA. During mitosis, duplicated chromosomes separate and the cell divides into two daughter cells. Meiosis produces gametes through two cell divisions, resulting in four haploid cells each with half the number of chromosomes as the original cell. Crossing over in meiosis contributes to genetic variation between cells.
4. Cell division - Anatomy - BSc Nursing 1st Semester - by M. Thirumurugan.pptxthiru murugan
It is the process by which a parent cell divides into two or more daughter cells. Cell division usually occurs as part of a larger cell cycle.
It is an essential biological process in many organisms. It is the means used by multicellular organisms in order to grow, repair, and reproduce.
Types of Cell division:
Mitosis
Meiosis
Mitosis: Mitosis is a division of the nucleus to produce two new daughter cells containing chromosomes identical to the parent cell.
Phases of Mitosis:
Mitosis is a continuous process and divided into different phases based on the appearance and behavior of the chromosomes.
Prophase
Prometaphase
Metaphase
Anaphase
Telophase
Cytokinesis
1.Prophase:
Early prophase:
During prophase chromatin (the complex of DNA and proteins contained in the nucleus), condense and become visible in a light microscope
Nucleolus disappears & Paired centrioles move to opposite ends of the cell.
The replicated chromosomes have an X shape and are called sister chromatids. The sister chromatids are joined at a point called the centromere.
Late prophase:
Nuclear membrane disappears
a structure called the mitotic spindle begins to form at opposite ends of the cell (responsible for separating the sister chromatids into two cells)
2. Prometaphase: Prometaphase is the second stage of mitosis. In prometaphase,
Chromosomes continue to condense
Kinetochores appear at the centromeres
Mitotic spindle attach to kinetochores
Centrosomes move toward opposite poles
3. Metaphase:
Metaphase is the third step in mitosis.
Mitotic spindle is fully developed
Sister chromatids line up at the spindle equator
At the end of metaphase, the centromeres start to divide
4.Anaphase:
Anaphase begin with the separation of the centromeres
Sister chromatids together break down
Sister chromatids (now called chromosomes) are pulled toward opposite poles
The sister chromatids are drawn to opposite poles of the cell by contraction of spindle fibers
5.Telophase:
Telophase begin when the two sets of daughter chromosomes have reached the two poles of the cell.
The spindle fibers breaks down,
The nuclear membrane forms around each set of daughter chromosomes and the nucleoli reappear
The chromosomes uncoil and become less visible under the light microscope
6. Cytokinesis:
Cytokinesis is the sixth and final step of mitosis & A cleavage furrow separates the daughter cells
Cytokinesis is the process of cytoplasmic division to form two daughter cells.
Cytokinesis takes place when the Cytoplasm divides and two cells with identical genetic material are formed Daughter Cells
Meiosis:
Meiosis Takes place in the Gametes of an organism
People have a Chromosome count of 46
When an egg joins a sperm the count must stay at 46 to remain human
So, the egg can only have 23 chromosomes, and the sperm can only have 23 chromosomes
But, the integrity of the organism must be maintained.
During Meiosis diploid cells are reduced to haploid cells
Diploid (2n) to Haploid (n):
During Meiosis gamete (sex
Cell division occurs through either mitosis or meiosis. Mitosis produces two identical daughter cells during somatic cell division. It has four phases: prophase, metaphase, anaphase and telophase. Meiosis produces gametes through two cell divisions that result in four haploid cells each with one copy of each chromosome. Meiosis has two rounds: meiosis I which separates homologous chromosomes, and meiosis II which separates sister chromatids. Both ensure genetic variation between offspring.
The study of the cell cycle focuses on mechanisms that regulate the timing and frequency of DNA duplication and cell division. As a biological concept, the cell cycle is defined as the period between successive divisions of a cell. During this period, the contents of the cell must be accurately replicated.
The cell cycle is regulated by cyclins and cyclin-dependent kinases.
How long is one cell cycle?
Depends. Eg. Skin cells every 24 hours. Some bacteria every 2 hours. Some cells every 3 months. Cancer cells very short. Nerve cells never.
Programmed cell death:
Each cell type will only do so many cell cycles then die. (Apoptosis)
M-phase consists of mitosis and cytokinesis. Mitosis is divided into prophase, metaphase, anaphase and telophase where the chromosomes condense and duplicate, align at the metaphase plate, separate into daughter chromosomes, and decondense. Cytokinesis then occurs, where in animal cells the cell membrane invaginates at the cleavage furrow to divide the cytoplasm, and in plant cells a cell plate forms between nuclei that fuses with the parent cell membrane to divide the cell.
Chapter 5 cell division SPM Biology Form 4Yee Sing Ong
Mitosis and meiosis both involve cell division, but have key differences:
Mitosis produces two identical diploid daughter cells through one nuclear division, while meiosis produces four non-identical haploid gametes through two nuclear divisions. Meiosis involves homologous chromosome pairing and crossing over during prophase I, which introduces genetic variation. The first meiotic division reduces the chromosome number by half to produce haploid cells, and the second division separates sister chromatids. Meiosis is essential for sexual reproduction to generate egg and sperm cells.
Cell division is the process by which a parent cell divides into two or more daughter cells. There are two main types of cell division: mitosis and meiosis. Mitosis produces two identical daughter cells during growth and repair of the body. It ensures the genetic makeup remains the same. Meiosis produces gametes with half the number of chromosomes and involves two cell divisions. It results in genetic diversity that is important for sexual reproduction.
Cell division occurs through binary fission in prokaryotes, where the genetic material duplicates and the cell splits into two identical daughter cells. Eukaryotes undergo the more complex processes of mitosis and meiosis. Mitosis produces two identical daughter cells during normal cell growth and replacement. Meiosis results in four haploid cells through two cell divisions, reducing the chromosome number by half and allowing for genetic variation in sexual reproduction.
This document provides an overview of cell division and the cell cycle. It begins with acknowledging various universities and organizations. It then lists the course objectives which are to explain the importance of cell division, discuss the cell cycle stages of mitosis and interphase, describe the four stages of mitosis, and discuss cell cycle control mechanisms. The document proceeds to define key terms, describe the stages of interphase and mitosis, and explain chromosomes, the mitotic spindle apparatus, and control of the cell cycle through cyclins and CDKs. It concludes by noting some key points about mitosis and introducing meiosis.
The cell cycle consists of 4 main phases - G1, S, G2, and M phase. During interphase (G1, S, G2 phases), the cell grows and duplicates its DNA. Mitosis (M phase) then follows, which divides the cell into two identical daughter cells through four stages: prophase, metaphase, anaphase and telophase. Cytokinesis subsequently divides the cytoplasm.
Chromosomes contain DNA and proteins. During cell division, the DNA is copied and organized into chromosomes. Mitosis produces identical daughter cells while meiosis reduces the chromosome number by half to produce gametes. Meiosis involves two cell divisions, resulting in four haploid cells. Genetic recombination occurs during meiosis, increasing genetic variation in offspring.
The document discusses cell division through the cell cycle, mitosis, and meiosis. The cell cycle consists of interphase (G1, S, and G2 phases) and mitosis, which produces two daughter cells with identical chromosomes to the parent cell. Mitosis involves four stages - prophase, metaphase, anaphase, and telophase. Meiosis produces haploid cells through two nuclear divisions and involves prophase I, metaphase I, anaphase I, telophase I, prophase II, metaphase II, anaphase II and telophase II.
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
The document summarizes the processes of mitosis and meiosis in eukaryotic cells. It describes the stages of the cell cycle including interphase and mitosis. Mitosis is divided into prophase, metaphase, anaphase and telophase where chromosomes are aligned and separated. Meiosis produces gametes through two cell divisions and a single DNA replication. This reduces the chromosome number by half to maintain genetic diversity between generations. Crossing over and random chromosome segregation in meiosis lead to genetic variation important for evolution.
CELL CYCLE , MITOSIS ,MEIOSIS AND CELL REGULATIONLIFE SCIENCES
The document discusses the cell cycle and its regulation. It describes the main phases of the cell cycle including interphase with G1, S, and G2 phases, and mitosis. It also covers meiosis and the key differences between mitosis and meiosis. Cell cycle checkpoints are mentioned which allow the cell cycle to be halted at certain points if conditions are not favorable for progression.
Cytokinesis involves the division of the cytoplasm following mitosis to form two daughter cells. It begins before nuclear division is complete. In animal cells, actin filaments contract to form a cleavage furrow that deepens and separates the cell into two daughters. In plant cells, membrane vesicles gather at the equator and fuse to form a cell plate, which grows outward and fuses with the parent cell's membrane to produce new cell walls.
The cell cycle is the series of growth and division steps that cells undergo. It includes interphase, where the cell grows and duplicates its DNA, and mitosis, where the cell separates its DNA and divides into two daughter cells. Interphase consists of G1 phase, S phase where DNA replicates, and G2 phase. Mitosis then occurs in four phases - prophase, metaphase, anaphase and telophase - where the duplicated chromosomes separate and the cell divides. Cytokinesis then divides the cytoplasm, forming two new identical daughter cells to complete the cell cycle.
This document defines key terms related to cell division and DNA, describes the main stages of the cell cycle and mitosis, and explains the significance of mitosis. It states that mitosis results in two daughter cells that are genetically identical to the parent cell, ensuring genetic stability. It occurs in two phases: nuclear division and cytoplasm division. The four stages of mitosis are prophase, metaphase, anaphase and telophase. Cytokinesis then divides the cytoplasm through cleavage or cell plate formation in animal and plant cells respectively.
This document defines key terms related to cell division, DNA, chromosomes, and genetics. It describes the two main types of cell division - mitosis and meiosis. Mitosis is defined as nuclear division that results in daughter cells with the same number of chromosomes as the parent cell, while meiosis results in daughter cells with half the number of chromosomes. The stages of the cell cycle are explained as G1, S phase, G2, and mitosis. The stages of mitosis and differences between plant and animal cell cytokinesis are summarized. Significance of mitosis includes genetic stability, growth, cell replacement, regeneration, and asexual reproduction.
This document provides an overview of cell division through mitosis and meiosis. It explains that all living things are made of cells, and cells must divide for organisms to grow and replace old cells. The cell cycle is described, including the main stages of interphase, mitosis, and cytokinesis. Interphase consists of G1, S, and G2 phases where the cell grows and duplicates its DNA. During mitosis, duplicated chromosomes separate and the cell divides into two daughter cells. Meiosis produces gametes through two cell divisions, resulting in four haploid cells each with half the number of chromosomes as the original cell. Crossing over in meiosis contributes to genetic variation between cells.
4. Cell division - Anatomy - BSc Nursing 1st Semester - by M. Thirumurugan.pptxthiru murugan
It is the process by which a parent cell divides into two or more daughter cells. Cell division usually occurs as part of a larger cell cycle.
It is an essential biological process in many organisms. It is the means used by multicellular organisms in order to grow, repair, and reproduce.
Types of Cell division:
Mitosis
Meiosis
Mitosis: Mitosis is a division of the nucleus to produce two new daughter cells containing chromosomes identical to the parent cell.
Phases of Mitosis:
Mitosis is a continuous process and divided into different phases based on the appearance and behavior of the chromosomes.
Prophase
Prometaphase
Metaphase
Anaphase
Telophase
Cytokinesis
1.Prophase:
Early prophase:
During prophase chromatin (the complex of DNA and proteins contained in the nucleus), condense and become visible in a light microscope
Nucleolus disappears & Paired centrioles move to opposite ends of the cell.
The replicated chromosomes have an X shape and are called sister chromatids. The sister chromatids are joined at a point called the centromere.
Late prophase:
Nuclear membrane disappears
a structure called the mitotic spindle begins to form at opposite ends of the cell (responsible for separating the sister chromatids into two cells)
2. Prometaphase: Prometaphase is the second stage of mitosis. In prometaphase,
Chromosomes continue to condense
Kinetochores appear at the centromeres
Mitotic spindle attach to kinetochores
Centrosomes move toward opposite poles
3. Metaphase:
Metaphase is the third step in mitosis.
Mitotic spindle is fully developed
Sister chromatids line up at the spindle equator
At the end of metaphase, the centromeres start to divide
4.Anaphase:
Anaphase begin with the separation of the centromeres
Sister chromatids together break down
Sister chromatids (now called chromosomes) are pulled toward opposite poles
The sister chromatids are drawn to opposite poles of the cell by contraction of spindle fibers
5.Telophase:
Telophase begin when the two sets of daughter chromosomes have reached the two poles of the cell.
The spindle fibers breaks down,
The nuclear membrane forms around each set of daughter chromosomes and the nucleoli reappear
The chromosomes uncoil and become less visible under the light microscope
6. Cytokinesis:
Cytokinesis is the sixth and final step of mitosis & A cleavage furrow separates the daughter cells
Cytokinesis is the process of cytoplasmic division to form two daughter cells.
Cytokinesis takes place when the Cytoplasm divides and two cells with identical genetic material are formed Daughter Cells
Meiosis:
Meiosis Takes place in the Gametes of an organism
People have a Chromosome count of 46
When an egg joins a sperm the count must stay at 46 to remain human
So, the egg can only have 23 chromosomes, and the sperm can only have 23 chromosomes
But, the integrity of the organism must be maintained.
During Meiosis diploid cells are reduced to haploid cells
Diploid (2n) to Haploid (n):
During Meiosis gamete (sex
Cell division occurs through either mitosis or meiosis. Mitosis produces two identical daughter cells during somatic cell division. It has four phases: prophase, metaphase, anaphase and telophase. Meiosis produces gametes through two cell divisions that result in four haploid cells each with one copy of each chromosome. Meiosis has two rounds: meiosis I which separates homologous chromosomes, and meiosis II which separates sister chromatids. Both ensure genetic variation between offspring.
The study of the cell cycle focuses on mechanisms that regulate the timing and frequency of DNA duplication and cell division. As a biological concept, the cell cycle is defined as the period between successive divisions of a cell. During this period, the contents of the cell must be accurately replicated.
The cell cycle is regulated by cyclins and cyclin-dependent kinases.
How long is one cell cycle?
Depends. Eg. Skin cells every 24 hours. Some bacteria every 2 hours. Some cells every 3 months. Cancer cells very short. Nerve cells never.
Programmed cell death:
Each cell type will only do so many cell cycles then die. (Apoptosis)
M-phase consists of mitosis and cytokinesis. Mitosis is divided into prophase, metaphase, anaphase and telophase where the chromosomes condense and duplicate, align at the metaphase plate, separate into daughter chromosomes, and decondense. Cytokinesis then occurs, where in animal cells the cell membrane invaginates at the cleavage furrow to divide the cytoplasm, and in plant cells a cell plate forms between nuclei that fuses with the parent cell membrane to divide the cell.
Chapter 5 cell division SPM Biology Form 4Yee Sing Ong
Mitosis and meiosis both involve cell division, but have key differences:
Mitosis produces two identical diploid daughter cells through one nuclear division, while meiosis produces four non-identical haploid gametes through two nuclear divisions. Meiosis involves homologous chromosome pairing and crossing over during prophase I, which introduces genetic variation. The first meiotic division reduces the chromosome number by half to produce haploid cells, and the second division separates sister chromatids. Meiosis is essential for sexual reproduction to generate egg and sperm cells.
Cell division is the process by which a parent cell divides into two or more daughter cells. There are two main types of cell division: mitosis and meiosis. Mitosis produces two identical daughter cells during growth and repair of the body. It ensures the genetic makeup remains the same. Meiosis produces gametes with half the number of chromosomes and involves two cell divisions. It results in genetic diversity that is important for sexual reproduction.
Cell division occurs through binary fission in prokaryotes, where the genetic material duplicates and the cell splits into two identical daughter cells. Eukaryotes undergo the more complex processes of mitosis and meiosis. Mitosis produces two identical daughter cells during normal cell growth and replacement. Meiosis results in four haploid cells through two cell divisions, reducing the chromosome number by half and allowing for genetic variation in sexual reproduction.
This document provides an overview of cell division and the cell cycle. It begins with acknowledging various universities and organizations. It then lists the course objectives which are to explain the importance of cell division, discuss the cell cycle stages of mitosis and interphase, describe the four stages of mitosis, and discuss cell cycle control mechanisms. The document proceeds to define key terms, describe the stages of interphase and mitosis, and explain chromosomes, the mitotic spindle apparatus, and control of the cell cycle through cyclins and CDKs. It concludes by noting some key points about mitosis and introducing meiosis.
The cell cycle consists of 4 main phases - G1, S, G2, and M phase. During interphase (G1, S, G2 phases), the cell grows and duplicates its DNA. Mitosis (M phase) then follows, which divides the cell into two identical daughter cells through four stages: prophase, metaphase, anaphase and telophase. Cytokinesis subsequently divides the cytoplasm.
Chromosomes contain DNA and proteins. During cell division, the DNA is copied and organized into chromosomes. Mitosis produces identical daughter cells while meiosis reduces the chromosome number by half to produce gametes. Meiosis involves two cell divisions, resulting in four haploid cells. Genetic recombination occurs during meiosis, increasing genetic variation in offspring.
The document discusses cell division through the cell cycle, mitosis, and meiosis. The cell cycle consists of interphase (G1, S, and G2 phases) and mitosis, which produces two daughter cells with identical chromosomes to the parent cell. Mitosis involves four stages - prophase, metaphase, anaphase, and telophase. Meiosis produces haploid cells through two nuclear divisions and involves prophase I, metaphase I, anaphase I, telophase I, prophase II, metaphase II, anaphase II and telophase II.
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
LAND USE LAND COVER AND NDVI OF MIRZAPUR DISTRICT, UPRAHUL
This Dissertation explores the particular circumstances of Mirzapur, a region located in the
core of India. Mirzapur, with its varied terrains and abundant biodiversity, offers an optimal
environment for investigating the changes in vegetation cover dynamics. Our study utilizes
advanced technologies such as GIS (Geographic Information Systems) and Remote sensing to
analyze the transformations that have taken place over the course of a decade.
The complex relationship between human activities and the environment has been the focus
of extensive research and worry. As the global community grapples with swift urbanization,
population expansion, and economic progress, the effects on natural ecosystems are becoming
more evident. A crucial element of this impact is the alteration of vegetation cover, which plays a
significant role in maintaining the ecological equilibrium of our planet.Land serves as the foundation for all human activities and provides the necessary materials for
these activities. As the most crucial natural resource, its utilization by humans results in different
'Land uses,' which are determined by both human activities and the physical characteristics of the
land.
The utilization of land is impacted by human needs and environmental factors. In countries
like India, rapid population growth and the emphasis on extensive resource exploitation can lead
to significant land degradation, adversely affecting the region's land cover.
Therefore, human intervention has significantly influenced land use patterns over many
centuries, evolving its structure over time and space. In the present era, these changes have
accelerated due to factors such as agriculture and urbanization. Information regarding land use and
cover is essential for various planning and management tasks related to the Earth's surface,
providing crucial environmental data for scientific, resource management, policy purposes, and
diverse human activities.
Accurate understanding of land use and cover is imperative for the development planning
of any area. Consequently, a wide range of professionals, including earth system scientists, land
and water managers, and urban planners, are interested in obtaining data on land use and cover
changes, conversion trends, and other related patterns. The spatial dimensions of land use and
cover support policymakers and scientists in making well-informed decisions, as alterations in
these patterns indicate shifts in economic and social conditions. Monitoring such changes with the
help of Advanced technologies like Remote Sensing and Geographic Information Systems is
crucial for coordinated efforts across different administrative levels. Advanced technologies like
Remote Sensing and Geographic Information Systems
9
Changes in vegetation cover refer to variations in the distribution, composition, and overall
structure of plant communities across different temporal and spatial scales. These changes can
occur natural.
Beyond Degrees - Empowering the Workforce in the Context of Skills-First.pptxEduSkills OECD
Iván Bornacelly, Policy Analyst at the OECD Centre for Skills, OECD, presents at the webinar 'Tackling job market gaps with a skills-first approach' on 12 June 2024
Communicating effectively and consistently with students can help them feel at ease during their learning experience and provide the instructor with a communication trail to track the course's progress. This workshop will take you through constructing an engaging course container to facilitate effective communication.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) CurriculumMJDuyan
(𝐓𝐋𝐄 𝟏𝟎𝟎) (𝐋𝐞𝐬𝐬𝐨𝐧 𝟏)-𝐏𝐫𝐞𝐥𝐢𝐦𝐬
𝐃𝐢𝐬𝐜𝐮𝐬𝐬 𝐭𝐡𝐞 𝐄𝐏𝐏 𝐂𝐮𝐫𝐫𝐢𝐜𝐮𝐥𝐮𝐦 𝐢𝐧 𝐭𝐡𝐞 𝐏𝐡𝐢𝐥𝐢𝐩𝐩𝐢𝐧𝐞𝐬:
- Understand the goals and objectives of the Edukasyong Pantahanan at Pangkabuhayan (EPP) curriculum, recognizing its importance in fostering practical life skills and values among students. Students will also be able to identify the key components and subjects covered, such as agriculture, home economics, industrial arts, and information and communication technology.
𝐄𝐱𝐩𝐥𝐚𝐢𝐧 𝐭𝐡𝐞 𝐍𝐚𝐭𝐮𝐫𝐞 𝐚𝐧𝐝 𝐒𝐜𝐨𝐩𝐞 𝐨𝐟 𝐚𝐧 𝐄𝐧𝐭𝐫𝐞𝐩𝐫𝐞𝐧𝐞𝐮𝐫:
-Define entrepreneurship, distinguishing it from general business activities by emphasizing its focus on innovation, risk-taking, and value creation. Students will describe the characteristics and traits of successful entrepreneurs, including their roles and responsibilities, and discuss the broader economic and social impacts of entrepreneurial activities on both local and global scales.
2. INTRODUCTION
• Living matter – able to reproduce
• Unicellular – duplication – cell division – enlarge
to get original size
• multicellular- - zygote – cell division - growth and
development – adult.
• History:
• Prevost and Dumas – 1824 – cleavage of zygote
• Remak – 1841 - new cells from pre-existing cells
• Rudolf Virchow – 1855, 1859 – cell lineage theory
3. • Strasburger – 1873 – two nuclei develop from pre-
existing one
• Boveri and Flemming – 1879-80 – somatic cell division
• Flemming – 1882 – coined the term ‘MITOSIS’
• Braur, Sutton, Van-Benden, Strasburger and Winiwater
– 1887-1900 – studied meiosis
• Farmer and Moore – 1905 – coined the term ‘MEIOSIS’
• Gregorie – Meiosis I and Meiosis II
• Howard and Pele – 1953 – Cell Cycle
• Montegomery – coined term ‘synapsis’
• Montose J. Moses – 1955 – Synaptonemal complex
4. • Cell cycle -> sequence of growth and division
-> formation of cell from parent cell -> division
-> daughter cell -> cell cycle
• Generation time -> period between two
divisions -> depends upon various factors.
• Generation time of E.coli - 20 minutes
• Epithelial cells – 8 to 10 hours
• Onion root tip meristems – 20 hours
5. • Phases of cell cycle:
• 1. long undividing state – interphase
• 2. short phase of nuclear division,
Multiplication or M phase
6. • Interphase:
• Preparing for mitosis
• Doubling of DNA, studied using autoradiography
with labelled thymidine
• Synthesis of DNA in synthetic period or S phase
• Followed by two “gaps” – G1 and G2
• Not a resting period
• Intense metabolism
• DNA uncoiled , visible as chromatin
• Volume of nucleus increases
• Nucleolus maximum size
7. • More ATP form from biomolecules
• Molecules needed stored
• Period 10 – 20 hours – 75 to 90% of
generation time
• Damaged DNA repaired
• FISH can be done – Fluoresccence in situ
hybridization. Fluorophore, sulfoindocyasin is
used to visualize DNA
8. • Starting point – gap1 (G1) active, make cell
components needed for cell progeny
• Next S phase – synthesis of DNA and proteins
like spindle fibres
• Next gap 2 (G2) – additional proteins, no DNA
synthesis
• No DNA synthesis in G1 and G2.
9. • M. phase - Multiplication phase – actual cell
division
• Karyokinesis
• Stages – Prophase, metaphase, anaphase,
telophase and cytokinesis
• Then daughter cell enters G1 or Go phase
• G1 phase is also called antephase
• Go phase –discovered by Lajtha – 1963
• If DNA is damaged P53 protein block cell cycle
leads to cell death or apoptosis
10.
11.
12. Cell Division
• Formation of daughter cell from parent cell
• Continuity from one generation to another
• Hereditary materials copied
• In sex cells division daughter cell may differ
• Prokaryotic cells divide by binary fission
• Single DNA – replicate – separated to cells – identical –
except mutation
• Multi cellular organisms replace worn out cells by cell
division
• Cell division halts – senescence – deterioration – death
• Telomere degeneration – cannot protect chromosomes
• Cancer cells – telomere allows continuous division
13. • Amitosis:
• Direct cell division
• No equal division of nucleus, no differentiation of
chromosomes and spindle
• Nuclear membrane does not disappear
• Nucleus elongate and divide by constriction
• Centripetal constriction of cytoplasm
• Examples: Protozoa, mammalian cartilage,
bacteria
• Unequal distribution may leads to structural and
functional abnormalities
14.
15. Mitosis
• Means – ‘thread of fibres’ in Greek
• Formation of identical cells, cellular xerox
• Fleming coined the term
• Phases:
• Interphase: period between two mitosis, resting
and preparatory phase
• Replication of DNA, synthesis of nuclear proteins,
formation of centriole, synthesis of ATP,
formation of spindle
• Duplication of chromosome – monads to dyad
16.
17. • Prophase:
• Cell become spheroid
• Increase in viscosity, and refractivity
• Chromatin reticulum disappears
• Shortening and thickening of chromosome fibers
• Outside the nucleus two centrosomes formed by
microtubules of tubilin protein
• Due to repulsive interaction of tubules centrosomes
push to the opposite ends of the cell
• In animal cells and fungi fibrils form like a spokes of a
wheel called aster
18. • Centriole participate – centric mitosis
• Plants no centriole – acentric mitosis
• Aster formation in animals and fungi –astral mitosis
• No aster – an-astral mitosis
• Spindle form between two poles
• Microtubules number 16 in yeast and 5000 in higher
plants
• Two types of centrioles – central spindle for
centrosome division during early prophase and
metaphasic centrioles for anaphasic movement of
chromosomes
19. • Disappearance of nuclear membrane and no
differentiation of cytoplasm and nucleoplasm
• Each chromosome form two kinetochore at
the centromere, one attached to each
chromatid for attachment of microtubules and
formation of spindle fibres
20.
21.
22.
23. • Metaphase:
• Chromosomes reaches central equatorial plane
• Smaller chromosomes at the center and larger chromosomes at the
periphery
• Centriole lie at the poles
• Continuous spindle fibres form fro pole to pole, not attached to
chromosomes, form stem-korper or pushing body and help in
separation
• Chromosomal fibres connect kinetochore and pole, pull
chromosomes
• Inter-zonal fibres connect centromere and pole, pull chromosomes
• Bringing chromosomes on the equator of the spindles is called
congression
• Spindle – 90-95% tubulin, 3-5% RNA and traces of actin, myosin and
lipid
24.
25. • Anaphase:
• Separation of centromere
• Pulling of chromosomes to poles by spindle
• At the end two groups of chromosomes with
equal number form at the pole equal to
parental cell
26.
27. • Telophase:
• Reversal of prophase
• Two nuclei form and nuclear membrane appear
• Spindle fibres and aster disappear
• Cytokinesis:
• Animal cell cleavage furrow form to become two
cells
• Plant cell - cellplate – cell wall and middle lamella
form to become two cells
30. MEIOSIS
• “Meio” means to lessen
• Farmer and Moore 1905 coined the term
• First studied by Van Benedin – 1887
• Strasburger – 1888, Sutton - !900,
Winiwater – 1900.
• Gregoire – Meiosis I and Meioisis II
• Diploid cell become haploid cells
31. • Haploid gametes form from diploid cell
• During sexual reproduction in eukaryotes.
• Male and female gametes fuse to form zygote
• One of the main reasons for variations
• Chromosome number constant
• Variations are the basis of evolution
32. • Types:
• 1. Zygotic life cycle: Initial Meiosis
• Haploid organism -> male and female gametes fusion -
> Zygote ( diploid) -> meiosis -> four haploid cells ->
new organism. Eg: Bryophytes
• 2. Gametic life cycle: Terminal Meiosis
• Organism diploid -> germ cells -> meiosis -> gametes ->
fusion of gametes -> zygote -> organism Eg: Human
beings
• 3. Sporic Meiosis: Diplohaplontic, intermediate meiosis
• Diploid sporophyte -> meiosis -> micro and
megaspores -> male and female gametes by mitosis ->
Zygote after fusion -> embryo -> that is meiosis
between zygote and gamete
33. • Phases of meiosis:
• Meiosis I:
• Prophase I:
• Leptotene : slender tread of chromatin become
chromosomes after condensation in nucleus
• It looks like thread of beads – chromomeres
• Irregularly arranged or towards centriole forming
a “ bouquet”. It is due to chromosome
attachment to nuclear membrane.
• In plant cells form tangle of threads – “Synezetic
knot”
34. • Zygotene: Mating thread
• Chromosome become shorter and thickened
• Pairing of homologous chromosomes “
Synapsis” or “Syndesis” or Synizesis”
• Pairing from centromere to ends – Procentric or
from end to centre – Proterminal pairing
• Combined homologous chromosomes – bivalent.
• It is also called tetrad because of four sister
chromatids.
35. • Synaptonemal complex formed during
zygotene.
• It is a ribbon like structure formed between
pairing homologous chromosomes.
• It has central and lateral elements – LC fibres
central fibres connects chromosomes and
lateral elements connects nuclear membrane
36. • Pachytene: Thick thread
• Longest stage
• It begins when synapsis is completed
• Chromosome as bivalent or tetrad, that is each
bivalent with four chromatids
• Each pair of chromatids attached by a centromere
called sister chromatids
• Chromatids of different pair called non-sister
chromatids.
• Breakage and reunion after interchange between
them is called crossing over.
37. • Diplotene: Double thread
• Beginning of separation of paired homologous
chromosomes
• Held together at one or two points called
chiasmata
• Number of chiasmata varies depends on length
• Terminal or intertidal chiasma
• Chiasma displaced along the length –
terminalization due to despiraling of
chromosomes – expressed as terminalization
coefficent {T}
• Synaptimal complex disappear
38. • Diakinesis:
• Chromosomes more contracted
• Bivalents move towards periphery
• Homologous remain in contact by terminal
chiasmata.
• Nucleolus detached or disappear
39.
40.
41. • Metaphase I :
• Chromosomes arranged at the centre
• Spindle formed and attached to centromere of
the two homologous chromosomes
• Two centromeres of each bivalent lie on
opposite sides of the equatorial plate
• It differs from mitosis, that is each bivalent has
two centromeres.
42.
43. • Anaphase I :
• Homologous chromosomes move towards
poles
• Due to crossing over separating chromosomes
are different.
• Centromere do not divide like mitosis
44.
45. • Telophase I :
• Centromere arrives pole
• Each cell has half the number of
chromosomes, each with two chromatids
• Spindle fibres disappear
• Nuclear membrane form
• Chromosomes uncoil and become chromatin
• It is followed by cytokinesis.
46.
47. • Meiosis II :
• Like mitosis, but DNA do not duplicate
• Prophase II :
• Nuclear membrane, nucleolus disappear.
• Shortening and thickening of chromatids.
• Centrioles move to the poles and spindle fibres
arranged
• New equatorial plane rotated by 90o, that is
perpendicular to the previous plane
48. Metaphase II :
• Like mitosis chromosomes oriented on the
equatorial plate and attached with spindle fibres
• Anaphase II :
• Centromeres cleaved
• Allow the kinetochore to pull the sister
chromatids apart.
• Now become sister chromosomes and pulled
toward opposite poles.
49. • Telophase II :
• Like telophase I uncoiling, lengthening and
disappearance of chromosomes
• Nuclear membrane form
• Finally four haploid cells formed
50.
51. • Non-disjunction :
• Normal separation of chromosomes called
disjunction.
• If they are not properly separated leads to non-
disjunction
• Leads to more or less amount of genetic material
• Example – trisomy or monosomy
• Downs syndrome - trisomy of 21 chromosome
• Klinefelder’s syndrome – one extra X cromosome
52. • Significance of Meiosis:
• 1. Sexual reproduction
• 2. Genetic variation
• 3. Mutation
• 4. Genetic information for gametes or
gametophytes and sporophytes.