The document discusses cell cycle regulation and its role in preventing cancer. It describes the key checkpoints in the cell cycle, including the G1, G2, and spindle assembly checkpoints, which ensure DNA replication and chromosome segregation are accurate before the cell divides or progresses to the next phase. Dysregulation of the cell cycle checkpoints can lead to uncontrolled cell division and cancer. Apoptosis (programmed cell death) is also discussed as another mechanism that eliminates damaged or abnormal cells to maintain genomic stability.
The document discusses cell reproduction through mitosis and meiosis. It provides details on:
1) The stages of the cell cycle including interphase and the phases of mitosis (prophase, metaphase, anaphase, telophase).
2) The key differences between mitosis, which produces identical daughter cells, and meiosis, which produces gametes with half the number of chromosomes.
3) The stages and outcomes of meiosis I and meiosis II, which reduce the chromosome number and lead to genetic diversity through independent assortment and crossing over.
The document discusses the cell nucleus, providing details on its history, characteristics, structure, and functions. It describes how the nucleus was discovered in 1831 and named by Robert Brown. The nucleus is a membrane-bound organelle found at the center of eukaryotic cells that can vary in shape and size depending on the cell. It houses genetic material in the form of chromatin and chromosomes and directs protein synthesis, cell growth and regulation, and transportation between the nucleus and cytoplasm. The nucleus contains a nuclear membrane, nucleolus, chromatin, and DNA and serves as the command center of the cell.
The vascular cambium is a lateral meristem that increases the diameter of stems and roots through secondary growth. It is composed of fusiform initials that divide to form vertical tissues and ray initials that form horizontal tissues. In dicots, intrafascicular cambium initially develops within vascular bundles and interfascicular cambium develops between bundles, eventually joining to form a complete cambial ring. The cambium divides to produce secondary xylem internally and secondary phloem externally. Its seasonal activity varies the structure of the tissues produced.
Chloroplasts are organelles found in plant cells and other eukaryotic cells that are the site of photosynthesis. They contain chlorophyll and have a double membrane structure, with stacks of internal membranes called thylakoids that are the site of the light-dependent reactions of photosynthesis. During photosynthesis, chloroplasts capture energy from sunlight and use it to convert carbon dioxide and water into oxygen and energy-rich molecules like glucose through a two-stage process of light-dependent and light-independent reactions.
The document summarizes the key components and functions of xylem and phloem tissue in plants. Xylem tissue conducts water and minerals throughout the plant and is composed of tracheids and vessels. Phloem tissue conducts sugars and transports them from leaves to other plant parts. Phloem consists of sieve tubes made of elongated living cells called sieve elements connected end to end to form columns. Each sieve element has an associated companion cell that provides energy and nutrients to keep the sieve element alive via plasmodesmata.
Meiosis is a type of cell division that occurs in gamete cells and results in four daughter cells each with half the number of chromosomes as the original parent cell. It has two divisions: Meiosis I which separates homologous chromosome pairs, and Meiosis II which separates sister chromatids. The stages of meiosis are prophase I, metaphase I, anaphase I, telophase I, prophase II, metaphase II, anaphase II and telophase II. Crossing over in prophase I results in genetic variation by exchanging DNA between nonsister chromatids.
This document summarizes the different types of meristematic tissue in plants. Meristematic tissue consists of actively dividing cells that allow plants to grow and develop different cell types. There are three main types of meristematic tissue based on origin: promeristem, primary meristem, and secondary meristem. Additionally, meristematic tissue can be categorized based on position as apical, intercalary, or lateral meristems. Finally, meristematic tissue types can be distinguished based on their function in forming epidermal, vascular, or ground tissues systems or based on their plane of cell division as rib, plate, or mass meristems.
Microsporogenesis involves the formation of pollen grains in the anthers. It begins with the formation of archesporial cells that develop into primary sporogenous cells. These cells undergo mitosis and differentiate into microspore mother cells. The microspore mother cells undergo meiosis to form microspores still connected in tetrads. The tetrads separate into individual microspores which are released from the anther as mature pollen grains. Key tissues involved include the sporogenous tissue, tapetum, and anther wall layers.
The document discusses cell reproduction through mitosis and meiosis. It provides details on:
1) The stages of the cell cycle including interphase and the phases of mitosis (prophase, metaphase, anaphase, telophase).
2) The key differences between mitosis, which produces identical daughter cells, and meiosis, which produces gametes with half the number of chromosomes.
3) The stages and outcomes of meiosis I and meiosis II, which reduce the chromosome number and lead to genetic diversity through independent assortment and crossing over.
The document discusses the cell nucleus, providing details on its history, characteristics, structure, and functions. It describes how the nucleus was discovered in 1831 and named by Robert Brown. The nucleus is a membrane-bound organelle found at the center of eukaryotic cells that can vary in shape and size depending on the cell. It houses genetic material in the form of chromatin and chromosomes and directs protein synthesis, cell growth and regulation, and transportation between the nucleus and cytoplasm. The nucleus contains a nuclear membrane, nucleolus, chromatin, and DNA and serves as the command center of the cell.
The vascular cambium is a lateral meristem that increases the diameter of stems and roots through secondary growth. It is composed of fusiform initials that divide to form vertical tissues and ray initials that form horizontal tissues. In dicots, intrafascicular cambium initially develops within vascular bundles and interfascicular cambium develops between bundles, eventually joining to form a complete cambial ring. The cambium divides to produce secondary xylem internally and secondary phloem externally. Its seasonal activity varies the structure of the tissues produced.
Chloroplasts are organelles found in plant cells and other eukaryotic cells that are the site of photosynthesis. They contain chlorophyll and have a double membrane structure, with stacks of internal membranes called thylakoids that are the site of the light-dependent reactions of photosynthesis. During photosynthesis, chloroplasts capture energy from sunlight and use it to convert carbon dioxide and water into oxygen and energy-rich molecules like glucose through a two-stage process of light-dependent and light-independent reactions.
The document summarizes the key components and functions of xylem and phloem tissue in plants. Xylem tissue conducts water and minerals throughout the plant and is composed of tracheids and vessels. Phloem tissue conducts sugars and transports them from leaves to other plant parts. Phloem consists of sieve tubes made of elongated living cells called sieve elements connected end to end to form columns. Each sieve element has an associated companion cell that provides energy and nutrients to keep the sieve element alive via plasmodesmata.
Meiosis is a type of cell division that occurs in gamete cells and results in four daughter cells each with half the number of chromosomes as the original parent cell. It has two divisions: Meiosis I which separates homologous chromosome pairs, and Meiosis II which separates sister chromatids. The stages of meiosis are prophase I, metaphase I, anaphase I, telophase I, prophase II, metaphase II, anaphase II and telophase II. Crossing over in prophase I results in genetic variation by exchanging DNA between nonsister chromatids.
This document summarizes the different types of meristematic tissue in plants. Meristematic tissue consists of actively dividing cells that allow plants to grow and develop different cell types. There are three main types of meristematic tissue based on origin: promeristem, primary meristem, and secondary meristem. Additionally, meristematic tissue can be categorized based on position as apical, intercalary, or lateral meristems. Finally, meristematic tissue types can be distinguished based on their function in forming epidermal, vascular, or ground tissues systems or based on their plane of cell division as rib, plate, or mass meristems.
Microsporogenesis involves the formation of pollen grains in the anthers. It begins with the formation of archesporial cells that develop into primary sporogenous cells. These cells undergo mitosis and differentiate into microspore mother cells. The microspore mother cells undergo meiosis to form microspores still connected in tetrads. The tetrads separate into individual microspores which are released from the anther as mature pollen grains. Key tissues involved include the sporogenous tissue, tapetum, and anther wall layers.
This document summarizes secondary growth in dicot roots. It begins by explaining the importance of secondary growth in increasing a plant's ability to absorb and transport water and minerals. It then describes the anatomy of a dicot root, including the epidermis, cortex, endodermis, pericycle, vascular strands, and pith. The document notes that secondary growth in roots occurs through the formation of a cambial ring, unlike in dicot stems. It also provides brief definitions of xylem and phloem tissue and explains that roots can form periderm through a similar process of secondary growth.
Viruses and bacteria have important economic roles. Viruses are used to produce vaccines, study evolution, and control harmful bacteria. They are also important research tools in genetics and genetic engineering. Bacteria play key roles in agriculture by decomposing organic matter, fixing nitrogen, and solubilizing phosphorus to act as biofertilizers. They are also crucial in many industries like dairy, tea processing, tanning leather, and producing chemicals, vitamins, solvents, and fuels through fermentation. Bacteria also have medical uses as sources of antibiotics.
Spirogyra is a common freshwater green alga that forms long, thin filaments. It reproduces both asexually through fragmentation and sexually through conjugation. During conjugation, projections grow out from adjacent cells in different filaments and their contents fuse, forming zygospores. The zygospores are resistant and may lie dormant before germinating into new haploid filaments.
The nucleus is a double-membrane organelle found in eukaryotic cells that contains most of the cell's genetic material. It has a spherical shape but can be other shapes depending on the cell. The nucleus contains chromatin with DNA, nucleolus, and is surrounded by a nuclear envelope. It acts as the control center of the cell by transmitting genetic information for protein synthesis, cell division, growth and differentiation.
Mitosis is the process of cell division into two identical daughter cells. It is divided into five phases: interphase, prophase, metaphase, anaphase, and telophase. During interphase the chromosomes condense and the centrioles move to opposite poles. In prophase the chromosomes attach to the spindle by their kinetochores. Metaphase aligns the chromosomes in the center. Anaphase separates the sister chromatids and moves them to opposite poles. Telophase reforms the nuclei around the separated chromosomes.
The nuclear envelope encloses the DNA and defines the nuclear compartment. It is composed of an inner and outer nuclear membrane with nuclear pores that regulate transport between the nucleus and cytoplasm. The nuclear pores have a diameter between 10-100nm and their number, or pore density, correlates with a cell's transcriptional activity. Transport through the pores is regulated by signal proteins that open the pores to precisely the right extent to allow passage of molecules and particles between the nuclear and cytoplasmic compartments.
This document summarizes key details about the freshwater green alga Chara. It describes the order, common species, occurrence in freshwater ponds and lakes, thallus structure including main axis, nodes, branches, rhizoids, and cell structure. Reproduction is both vegetative through structures like bulbils and sexually through oogamous fertilization. Chara has economic importance as food for aquatic animals, in purifying water, as green manure, and used dried as an insect repellent.
The plant cell wall is the outermost non-living structure of plant cells located outside the plasma membrane. It is composed primarily of cellulose microfibrils embedded in a matrix of pectin, hemicellulose, lignin and sometimes waxes. The cell wall has three layers - the middle lamella, primary wall and secondary wall. The middle lamella acts as a cement between adjacent cell walls. The primary wall is thin and elastic. The secondary wall is thicker and provides strength and rigidity through tightly packed cellulose microfibrils and sometimes lignin. It has three layers - S1, S2 and S3. The cell wall gives mechanical support and protection to plant cells and regulates the passage of materials
The document summarizes key parts and functions of the nucleus. The nucleus contains nuclear membrane, nucleoplasm, chromatin, and nucleolus. It is surrounded by a double membrane nuclear envelope that contains pores allowing transport between the nucleus and cytoplasm. The nucleus controls all cell functions and carries hereditary material. It was discovered in 1831 and is present in all eukaryotic cells except mature red blood cells and phloem cells.
description of different types of reproductive organs, developmental stages and process of reproduction in Cycas. Various internet sources have been used.
The document describes the internal structures of dicot and monocot leaves. Dicot leaves have a dorsiventral structure with two epidermal layers, palisade and spongy mesophyll tissue, and collateral vascular bundles surrounded by bundle sheath cells. Monocot leaves are isobilateral with similar epidermal layers and intercellular mesophyll but lack distinct palisade and spongy tissues; they contain multiple conjoint vascular bundles surrounded by a double-layered bundle sheath. Both leaf types share epidermal layers, mesophyll, vascular bundles and differences in their internal organization.
Cycas is a gymnosperm that reproduces both vegetatively and sexually. Vegetative reproduction occurs through adventitious buds on the stem base that develop into new plants. Sexual reproduction involves separate male and female plants that produce cones. Pollen from the male cone is transferred to female cones by wind. After fertilization, the ovule develops into a seed protected by a fleshy outer layer and stony middle layer. The seed germinates by rupturing at the micropyle and producing a radicle and plumule to form a new sporophyte plant.
• The membrane enclosing a cell is called cell membrane or plasma membrane (animal cells) and plasma lemma (plant cells).
• It contains proteins and lipids in the ratio of 80 : 20 in bacteria on one extreme and on the other extreme 20 : 80 in some nerve cells.
• The over all composition of most of the cell membranes is 40-50% protein and 50-60% lipids; both the components vary in their composition.
This document summarizes key information about plant cell walls. It begins by introducing the topic and providing background on the discovery of cell walls. It then describes the main components of plant cell walls, including the three layers (middle lamella, primary cell wall, and secondary cell wall). The structural organization and chemical composition of cell walls is also summarized. Finally, the main functions of the cell wall in providing structure, protection, and facilitating transport are outlined.
The document provides links to resources about meristematic tissue structure and classification including a detailed description and YouTube video. It also lists additional resources available on the easybiologyclass website such as lecture notes, video tutorials, PPTs, MCQs, and CSIR and GATE study materials. Visitors are directed to related sites for angiosperm taxonomy and job notifications.
The document provides an overview of cell cycle and cell division. It defines a cell and discusses the cell theory. The cell cycle consists of interphase and M-phase. Interphase includes G1, S, and G2 phases where the cell grows and replicates its DNA. M-phase is when the cell divides, including mitosis and cytokinesis. Mitosis involves prophase, metaphase, anaphase and telophase. Meiosis reduces the chromosome number by half and produces gametes through two divisions. Cell division through mitosis and meiosis is essential for growth, tissue repair, asexual reproduction, and sexual reproduction.
The nucleus is an organelle found in eukaryotic cells that houses the cell's genetic material. It was first observed by Anton van Leeuwenhoek in the 17th century and further described by Robert Brown in the 19th century. The nucleus is surrounded by a double membrane called the nuclear envelope and contains chromatin fibers, nucleoplasm, and one or more nucleoli. It controls cell functions and stores the cell's genetic information in the form of DNA.
Simple tissues are composed of similar cell types that have a common origin and function. There are three main types: parenchyma, collenchyma, and sclerenchyma. Parenchyma tissue is made of living cells and performs functions like photosynthesis, storage, and gas exchange. Collenchyma cells provide support and flexibility to plant structures. Sclerenchyma cells are dead at maturity and provide strength and structure through thick lignified cell walls. Each tissue type has subcategories that differ in cell shape, arrangement, and specific functions.
Vacuoles are membrane-bound organelles present in plant, fungal, and some protist and animal cells. There are three main types of vacuoles: storage vacuoles, contractile vacuoles involved in osmoregulation, and vacuoles involved in autophagy. Plant cell vacuoles occupy most of the cell volume and provide structural support and storage. Fungal vacuoles maintain a low pH through V-type ATPase pumps. During cell division, vacuoles are segregated into daughter cells through actin filament transport mediated by myosin motor proteins.
Growth occurs through three main ways: multiplicative growth through cell division, auxetic growth through increased cell size, and accretionary growth through accumulation of substances between cells. The cell cycle consists of interphase (G1, S, G2 phases) and the mitotic phase (M phase). Cell division occurs through either mitosis in somatic cells or meiosis in germ cells. Mitosis results in two identical daughter cells through karyokinesis and cytokinesis, passing through prophase, metaphase, anaphase and telophase. Meiosis results in four haploid gametes through two cell divisions and one DNA replication, with its own prophase I, metaphase I, anaphase I, and tel
This document summarizes secondary growth in dicot roots. It begins by explaining the importance of secondary growth in increasing a plant's ability to absorb and transport water and minerals. It then describes the anatomy of a dicot root, including the epidermis, cortex, endodermis, pericycle, vascular strands, and pith. The document notes that secondary growth in roots occurs through the formation of a cambial ring, unlike in dicot stems. It also provides brief definitions of xylem and phloem tissue and explains that roots can form periderm through a similar process of secondary growth.
Viruses and bacteria have important economic roles. Viruses are used to produce vaccines, study evolution, and control harmful bacteria. They are also important research tools in genetics and genetic engineering. Bacteria play key roles in agriculture by decomposing organic matter, fixing nitrogen, and solubilizing phosphorus to act as biofertilizers. They are also crucial in many industries like dairy, tea processing, tanning leather, and producing chemicals, vitamins, solvents, and fuels through fermentation. Bacteria also have medical uses as sources of antibiotics.
Spirogyra is a common freshwater green alga that forms long, thin filaments. It reproduces both asexually through fragmentation and sexually through conjugation. During conjugation, projections grow out from adjacent cells in different filaments and their contents fuse, forming zygospores. The zygospores are resistant and may lie dormant before germinating into new haploid filaments.
The nucleus is a double-membrane organelle found in eukaryotic cells that contains most of the cell's genetic material. It has a spherical shape but can be other shapes depending on the cell. The nucleus contains chromatin with DNA, nucleolus, and is surrounded by a nuclear envelope. It acts as the control center of the cell by transmitting genetic information for protein synthesis, cell division, growth and differentiation.
Mitosis is the process of cell division into two identical daughter cells. It is divided into five phases: interphase, prophase, metaphase, anaphase, and telophase. During interphase the chromosomes condense and the centrioles move to opposite poles. In prophase the chromosomes attach to the spindle by their kinetochores. Metaphase aligns the chromosomes in the center. Anaphase separates the sister chromatids and moves them to opposite poles. Telophase reforms the nuclei around the separated chromosomes.
The nuclear envelope encloses the DNA and defines the nuclear compartment. It is composed of an inner and outer nuclear membrane with nuclear pores that regulate transport between the nucleus and cytoplasm. The nuclear pores have a diameter between 10-100nm and their number, or pore density, correlates with a cell's transcriptional activity. Transport through the pores is regulated by signal proteins that open the pores to precisely the right extent to allow passage of molecules and particles between the nuclear and cytoplasmic compartments.
This document summarizes key details about the freshwater green alga Chara. It describes the order, common species, occurrence in freshwater ponds and lakes, thallus structure including main axis, nodes, branches, rhizoids, and cell structure. Reproduction is both vegetative through structures like bulbils and sexually through oogamous fertilization. Chara has economic importance as food for aquatic animals, in purifying water, as green manure, and used dried as an insect repellent.
The plant cell wall is the outermost non-living structure of plant cells located outside the plasma membrane. It is composed primarily of cellulose microfibrils embedded in a matrix of pectin, hemicellulose, lignin and sometimes waxes. The cell wall has three layers - the middle lamella, primary wall and secondary wall. The middle lamella acts as a cement between adjacent cell walls. The primary wall is thin and elastic. The secondary wall is thicker and provides strength and rigidity through tightly packed cellulose microfibrils and sometimes lignin. It has three layers - S1, S2 and S3. The cell wall gives mechanical support and protection to plant cells and regulates the passage of materials
The document summarizes key parts and functions of the nucleus. The nucleus contains nuclear membrane, nucleoplasm, chromatin, and nucleolus. It is surrounded by a double membrane nuclear envelope that contains pores allowing transport between the nucleus and cytoplasm. The nucleus controls all cell functions and carries hereditary material. It was discovered in 1831 and is present in all eukaryotic cells except mature red blood cells and phloem cells.
description of different types of reproductive organs, developmental stages and process of reproduction in Cycas. Various internet sources have been used.
The document describes the internal structures of dicot and monocot leaves. Dicot leaves have a dorsiventral structure with two epidermal layers, palisade and spongy mesophyll tissue, and collateral vascular bundles surrounded by bundle sheath cells. Monocot leaves are isobilateral with similar epidermal layers and intercellular mesophyll but lack distinct palisade and spongy tissues; they contain multiple conjoint vascular bundles surrounded by a double-layered bundle sheath. Both leaf types share epidermal layers, mesophyll, vascular bundles and differences in their internal organization.
Cycas is a gymnosperm that reproduces both vegetatively and sexually. Vegetative reproduction occurs through adventitious buds on the stem base that develop into new plants. Sexual reproduction involves separate male and female plants that produce cones. Pollen from the male cone is transferred to female cones by wind. After fertilization, the ovule develops into a seed protected by a fleshy outer layer and stony middle layer. The seed germinates by rupturing at the micropyle and producing a radicle and plumule to form a new sporophyte plant.
• The membrane enclosing a cell is called cell membrane or plasma membrane (animal cells) and plasma lemma (plant cells).
• It contains proteins and lipids in the ratio of 80 : 20 in bacteria on one extreme and on the other extreme 20 : 80 in some nerve cells.
• The over all composition of most of the cell membranes is 40-50% protein and 50-60% lipids; both the components vary in their composition.
This document summarizes key information about plant cell walls. It begins by introducing the topic and providing background on the discovery of cell walls. It then describes the main components of plant cell walls, including the three layers (middle lamella, primary cell wall, and secondary cell wall). The structural organization and chemical composition of cell walls is also summarized. Finally, the main functions of the cell wall in providing structure, protection, and facilitating transport are outlined.
The document provides links to resources about meristematic tissue structure and classification including a detailed description and YouTube video. It also lists additional resources available on the easybiologyclass website such as lecture notes, video tutorials, PPTs, MCQs, and CSIR and GATE study materials. Visitors are directed to related sites for angiosperm taxonomy and job notifications.
The document provides an overview of cell cycle and cell division. It defines a cell and discusses the cell theory. The cell cycle consists of interphase and M-phase. Interphase includes G1, S, and G2 phases where the cell grows and replicates its DNA. M-phase is when the cell divides, including mitosis and cytokinesis. Mitosis involves prophase, metaphase, anaphase and telophase. Meiosis reduces the chromosome number by half and produces gametes through two divisions. Cell division through mitosis and meiosis is essential for growth, tissue repair, asexual reproduction, and sexual reproduction.
The nucleus is an organelle found in eukaryotic cells that houses the cell's genetic material. It was first observed by Anton van Leeuwenhoek in the 17th century and further described by Robert Brown in the 19th century. The nucleus is surrounded by a double membrane called the nuclear envelope and contains chromatin fibers, nucleoplasm, and one or more nucleoli. It controls cell functions and stores the cell's genetic information in the form of DNA.
Simple tissues are composed of similar cell types that have a common origin and function. There are three main types: parenchyma, collenchyma, and sclerenchyma. Parenchyma tissue is made of living cells and performs functions like photosynthesis, storage, and gas exchange. Collenchyma cells provide support and flexibility to plant structures. Sclerenchyma cells are dead at maturity and provide strength and structure through thick lignified cell walls. Each tissue type has subcategories that differ in cell shape, arrangement, and specific functions.
Vacuoles are membrane-bound organelles present in plant, fungal, and some protist and animal cells. There are three main types of vacuoles: storage vacuoles, contractile vacuoles involved in osmoregulation, and vacuoles involved in autophagy. Plant cell vacuoles occupy most of the cell volume and provide structural support and storage. Fungal vacuoles maintain a low pH through V-type ATPase pumps. During cell division, vacuoles are segregated into daughter cells through actin filament transport mediated by myosin motor proteins.
Growth occurs through three main ways: multiplicative growth through cell division, auxetic growth through increased cell size, and accretionary growth through accumulation of substances between cells. The cell cycle consists of interphase (G1, S, G2 phases) and the mitotic phase (M phase). Cell division occurs through either mitosis in somatic cells or meiosis in germ cells. Mitosis results in two identical daughter cells through karyokinesis and cytokinesis, passing through prophase, metaphase, anaphase and telophase. Meiosis results in four haploid gametes through two cell divisions and one DNA replication, with its own prophase I, metaphase I, anaphase I, and tel
The document describes DNA replication and recombinant DNA. It discusses the three main steps of DNA replication: unzipping, complementary base pairing, and joining of adjacent nucleotides. Recombinant DNA is defined as DNA from two different organisms that is spliced together, and some of its main uses are listed, including producing hormones, proteins, vaccines, and developing pest/disease resistant crops. The document also provides an example of an anti-freeze gene being inserted into yeast to produce a protein added to ice cream to make it smoother.
The document discusses the cell cycle and cell division. It describes the stages of mitosis including interphase, prophase, metaphase, anaphase, telophase and cytokinesis. Chromosomes, kinetochores, spindle fibers and checkpoints are involved in regulating the accurate division of genetic material. Meiosis is also covered, which involves two cell divisions and a reduction in chromosome number important for sexual reproduction and genetic variation. Abnormal cell division can lead to cancer if cells escape normal cell cycle controls.
This document discusses key concepts in genetics including genotype and phenotype. It introduces Gregor Mendel, the Austrian monk who discovered the basic principles of heredity by breeding pea plants. Mendel noticed that pea traits like color and height were inherited in predictable patterns. The document defines genotype as an organism's genetic makeup, and phenotype as its observable traits. Genes determine traits, and alleles are different forms of the same gene. Dominant alleles mask recessive alleles. The Punnett square is used to predict offspring genotypes and phenotypes from parental genotypes. Heterozygous and homozygous refer to having different or same alleles. Codominance is when both alleles are partially expressed.
This document summarizes meiosis and sexual life cycles. It discusses how meiosis and fertilization produce genetic variation through independent assortment of chromosomes, crossing over, and random fertilization. This genetic variation is the raw material for evolution by natural selection and allows organisms to evolve and adapt to their environment. Sexual reproduction, through meiosis and fertilization, generates new combinations of genes not present in the parents, increasing genetic diversity within populations.
The document discusses cell growth and reproduction. It describes how cell size is limited by diffusion rate, DNA, and surface area to volume ratio. It explains that organisms cannot be just one cell due to these size limitations. The cell cycle, including interphase and the four phases of mitosis (prophase, metaphase, anaphase, telophase), is described. Chromosomes, made of DNA, replicate and separate during cell division. The cell cycle is tightly regulated by cyclins and cyclin-dependent kinases to ensure proper cell division and growth.
This document discusses the cell cycle and cell division. It begins by explaining the importance of cell division for reproduction and growth in both unicellular and multicellular organisms. It then describes the main stages and roles of the cell cycle, including interphase and the mitotic phase. Key details are provided on DNA replication in S phase, chromosome behavior, and the stages of mitosis. The document emphasizes the critical roles of the mitotic spindle and centrosomes in proper chromosome separation during cell division. Diagrams illustrate these various stages and structures discussed in the text.
Cell reproduction occurs through the cell cycle and mitosis. The cell cycle consists of interphase, where the cell grows and duplicates its DNA, and mitosis, where the cell divides into two identical daughter cells. Mitosis is used for growth, tissue repair, asexual reproduction, and occurs in somatic cells through four stages - prophase, metaphase, anaphase and telophase. All cells are derived from pre-existing cells and must reproduce for growth, repair, replacement and reproduction of the species.
This document outlines key concepts in transmission genetics and Mendelian inheritance. It defines important genetic terms like genes, alleles, homozygous, heterozygous, dominant, and recessive. It reviews Gregor Mendel's experiments with pea plants in the 1860s, which disproved earlier hypotheses about inheritance and established the discrete units of inheritance that are passed from parents to offspring. The document also explains the concept of a monohybrid cross using a simple example and how it can be used to predict offspring genotypes and phenotypes based on Mendel's theory of segregation.
B.Sc. Biochemistry II Cellular Biochemistry Unit 3 Cell CycleRai University
The document discusses the cell cycle and cell division. It begins by explaining that all cells come from pre-existing cells and that cells divide through mitosis or binary fission to grow, repair damage, or replace old cells. The cell cycle consists of interphase, where the cell grows and DNA replicates, and mitosis, where the cell divides. Meiosis produces gametes through two cell divisions and results in four haploid cells rather than two identical diploid cells as in mitosis. The key stages and purposes of the cell cycle, mitosis, and meiosis are summarized.
B.Sc. Microbiology/Biotech II Cell biology and Genetics Unit 5 microbial gene...Rai University
1. Genetic linkage refers to the tendency of alleles located near each other on a chromosome to be inherited together during meiosis. Linkage mapping uses recombination frequencies between genetic markers to construct genetic maps showing the relative positions of genes.
2. Physical mapping techniques like restriction mapping cut DNA into fragments to construct overlapping contig maps of chromosome regions without regard to specific genes.
3. Bacterial cells can exchange genetic material through three main processes: conjugation, transduction, and transformation. These processes aid genetic recombination and variation in bacteria.
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.
Meiosis is a type of cell division that produces gametes, such as sperm or egg cells, with half the number of chromosomes. It involves two cell divisions: Meiosis I and Meiosis II. In Meiosis I, homologous chromosomes pair up and undergo crossing over, then separate so each daughter cell gets one chromosome of each pair. Meiosis II separates the sister chromatids, resulting in four haploid daughter cells with half the original number of chromosomes. This ensures genetic variation between gametes and offspring through independent assortment and crossing over.
Chapter 18 Cell Division Lesson 4 - The Importance of Mitosisj3di79
The document discusses the stages of mitosis in animal and plant cells, including interphase, prophase, metaphase, anaphase and telophase. It notes the importance of mitosis for growth, repair and asexual reproduction. For plant cells, it notes that centrioles are absent and a cell plate forms instead of cleavage. Precise control of DNA replication and mitosis ensures genetically stable daughter cells, while mistakes can lead to cancerous uncontrolled cell division.
This document discusses a genetic condition where about 1 in 50,000 newborns are affected. Symptoms include a high-pitched cry, downward slanted eyes, low birth weight, intellectual disability, webbed fingers or toes, and other physical abnormalities. Doctors focus on managing individual symptoms rather than curing the underlying genetic cause.
Genetic variation occurs due to three processes during meiosis: 1) Independent assortment of chromosomes, which randomly distributes maternal and paternal chromosomes to gametes, resulting in 16 possible combinations. 2) Crossing over allows exchange of genetic material between homologous chromosomes, generating recombinant chromosomes. 3) Random fertilization, where a single egg is fertilized by one of millions of possible sperm, combining the genetic variation from both parents. Together, these three sources maximize genetic diversity.
Sexual reproduction involves the combination of genetic material from two parent cells to form a new cell. It occurs through meiosis which produces haploid sex cells with half the number of chromosomes and through fertilization where an egg and sperm join. This maintains the diploid number of chromosomes and generates genetic variation in offspring, providing advantages for adaptation and selective breeding.
This document discusses the cell cycle and its relevance to cancer. It begins by describing the basic components and organelles of the cell. It then explains the different phases of the cell cycle, including interphase (G1, S, G2 phases) and mitosis. Key control mechanisms like cyclin-dependent kinases and checkpoints are described. Alterations in cell cycle pathways and genes can lead to uncontrolled cell proliferation and cancer. Understanding the cell cycle provides opportunities to target specific phases with chemotherapy or radiotherapy to treat cancer.
Samuel Beckett was an Irish writer born in 1906 near Dublin. He studied languages at Trinity College Dublin and later taught French and English in Belfast and Paris. He began writing in the late 1920s and is best known for his plays Waiting for Godot and Happy Days, as well as novels like Molloy and Malone Dies. Beckett was a pioneer of absurdist theater and modernist literature, stripping down language and plot to focus on fundamental human experiences like waiting, memory, and death. He won the Nobel Prize for Literature in 1969 and continued writing until his death in 1989, leaving a profound influence on generations of writers, playwrights and artists.
Cellular division occurs through two main types - mitosis and meiosis. Mitosis produces two identical daughter cells through the division of the nucleus. It has four stages: prophase, metaphase, anaphase and telophase. Meiosis produces gametes like eggs and sperm through two cell divisions. It reduces the chromosome number by half to produce four haploid cells from one diploid parent cell.
This document provides information about cellular division in eukaryotic cells. It discusses mitosis, which produces two identical daughter cells used for growth and repair, and meiosis, which reduces the chromosome number by half and produces gametes like eggs and sperm used in sexual reproduction. Meiosis involves two cell divisions - Meiosis I and Meiosis II - while mitosis only involves one division. The key stages of each process, like prophase, metaphase, anaphase and telophase, are described in detail.
Cellular division occurs through mitosis and binary fission. Mitosis produces two identical daughter cells through the four stages of prophase, metaphase, anaphase and telophase. During prophase, chromosomes condense and the mitotic spindle forms. In metaphase, chromosomes line up at the center. In anaphase, sister chromatids are pulled apart to opposite poles. Telophase involves nuclear envelope reformation and cytokinesis separates the cell into two identical daughter cells. Binary fission similarly produces two identical prokaryotic cells.
-Cell Division Process In Prokaryotes & Eukaryotes
-Compacting DNA into Chromosomes
-Types of Cell Reproduction
-Phases of the Cell Cycle
-Mitosis
-Meiosis
-Oogenesis & Spermatogenesis
-Comparison of Divisions
Cell reproduction can occur through asexual or sexual reproduction. Asexual reproduction involves one cell dividing into two identical daughter cells through processes like mitosis and binary fission. Sexual reproduction involves the joining of two different cells - an egg and sperm - through meiosis to form a new cell called a zygote.
Prokaryotes like bacteria undergo binary fission, where the single chromosome duplicates and the cell divides into two identical daughter cells. Eukaryotic cell division involves mitosis, where the nucleus divides through prophase, metaphase, anaphase and telophase stages. Cytokinesis then divides the cytoplasm and forms two identical daughter cells with the same number of chromosomes as the parent cell. Un
Cell division can occur via mitosis or meiosis. Mitosis produces two identical daughter cells with the same number of chromosomes as the parent cell and is used for growth and repair. Meiosis produces four haploid gametes through two cell divisions, reducing the chromosome number by half to allow sexual reproduction. Fertilization of an egg and sperm restores the full chromosome number.
Chapter-6Cell Cycle and DivisionCell Divisio.docxchristinemaritza
Chapter-6
Cell Cycle and Division
Cell Division
Cells reproduce by cell division, in which a parent cell normally gives rise to two daughter cells
Each daughter cell receives a complete set of hereditary information (DNA) from the parent cell and about half its cytoplasm
The hereditary information DNA is usually identical with that of the parent cell
The cell division of eukaryotic cells by which organisms grow or increase in number is called mitotic cell division
After cell division, the daughter cells may differentiate, becoming specialized for specific functions
The repeating pattern of divide, grow, and differentiate, then divide again is called the cell cycle
Most multicellular organisms have three categories of cells
1. stem cells
2. Other cells capable of dividing
3. Permanently differentiated cells
1.Stem cells :
- have two important characteristics: self-renewal, and the ability to differentiate into a variety of cell types
-Stem cells self-renew because they retain the ability to divide, perhaps for the entire life of the organism
-Some stem cells in early embryos can produce any of the specialized cell types of the entire body
2. Other cells capable of dividing
-Some cells other than stem cells are capable of continuing to divide, but typically differentiate into only one or two different cell types
-Dividing liver cells, for example, can only become more liver cells
3. Permanently differentiated cells
-Permanently differentiated cells differentiate and never divide again
-For example, most heart and brain cells cannot divide
CELL CYCLE
Both prokaryotic and eukaryotic cells have cell cycles that include growth, metabolic activity, DNA replication, and cell division
However, they have major structural and functional differences
Eukaryotic chromosome
Eukaryotic chromosomes are separated from the cytoplasm by a membrane-bound nucleus
Eukaryotic cells always have multiple chromosomes
Eukaryotic chromosomes are longer and have more DNA than prokaryotic chromosomes (human chromosomes are 10 to 80 times longer and have 10 to 50 times more DNA)
Genes
Genes are segments of the DNA of a chromosome
Genes are sequences of DNA from hundreds to thousands of nucleotides long
Each gene occupies a specific place, or locus (plural, loci) on the chromosome
Two important parts of chromosome
Two telomeres
One centromere
It temporarily holds two daughter DNA double helices together after DNA replication
It is the attachment site for microtubules that move the chromosomes during cell division
Homologous
11
Chromosomes that contain the same genes are called homologous chromosomes, or homologues
Cells with pairs of homologous chromosomes are called diploid, which means “double”
Cells with half the number of chromosomes are called haploid
Human Chromosomes
A typical human cell has ...
Cell reproduction occurs through mitosis and meiosis. Mitosis produces identical daughter cells and occurs in somatic cells for growth and repair. Meiosis reduces the chromosome number by half and produces gametes involved in sexual reproduction, where the union of male and female gametes leads to fertilization and the formation of a new individual with a mix of genetic material.
This document summarizes the cell cycle and cell division. It explains that the cell cycle includes interphase, where the cell grows and DNA is replicated, and cell division which includes mitosis of the nucleus and cytokinesis of the cytoplasm. Mitosis produces two identical daughter cells through the stages of prophase, metaphase, anaphase and telophase. Meiosis reduces the chromosome number by half and produces gametes like sperm and egg cells through two cell divisions. Fertilization restores the full chromosome number in the zygote.
The document describes the process of cell division through mitosis and meiosis. It explains that mitosis produces two identical daughter cells through one round of division, while meiosis produces four non-identical gametes through two rounds of division, reducing the chromosome number by half. The key stages of each process - interphase, prophase, metaphase, anaphase and telophase - are outlined in detail. Mitosis is described as important for growth and repair of somatic cells, while meiosis occurs in germ cells at sexual maturity to create genetic diversity through recombination during gamete formation.
Cells divide through the processes of mitosis and meiosis. Mitosis produces two identical daughter cells from one parent cell and is used for growth and repair. Meiosis produces four haploid gametes from one diploid cell and reduces the chromosome number by half, which is necessary for sexual reproduction to create genetically unique offspring. The key stages and events of each process, such as chromosome behavior and cell division, help ensure each new cell has the proper genetic makeup.
Cells undergo mitosis and meiosis to divide. Mitosis produces two identical daughter cells through prophase, metaphase, anaphase and telophase and is used for growth and repair. Meiosis produces four non-identical haploid gametes through two divisions and crossing over, which contributes to genetic variation important for sexual reproduction. Regulators like cyclins and CDKs control the cell cycle.
This document discusses eukaryotic cell reproduction and the cell cycle. It begins by describing chromosomes, which store genetic information. It then explains the differences between chromosomes and chromatin, and the process of chromosome duplication. The document outlines the stages of the cell cycle, including interphase and the four stages of mitosis (prophase, metaphase, anaphase, telophase). It provides details about each mitotic stage and the purpose of cell division to produce two identical daughter cells through cytokinesis. In summary, the document covers the key processes and stages involved in eukaryotic cell reproduction and the cell cycle, with a focus on chromosome behavior and mitosis.
Cells undergo mitosis or meiosis to divide. Mitosis produces two identical daughter cells from one parent cell during normal cell growth and repair. Meiosis produces four haploid gametes from one diploid cell for sexual reproduction. During meiosis, homologous chromosomes pair up and may exchange DNA segments through crossing over, introducing genetic variation into the gametes. The first meiotic division separates homologous chromosomes, while the second division separates sister chromatids to produce four unique haploid cells.
DNA is replicated before cell division so each new cell receives a complete copy. The cell cycle consists of interphase, where the cell grows and DNA replicates, and mitosis, where the cell divides. During mitosis, the nucleus divides into two identical nuclei, each containing the full set of chromosomes. Meiosis produces gametes through two cell divisions, resulting in four cells each with half the number of chromosomes as the original cell. This allows for genetic variation in offspring.
The document discusses the three main steps of animal development: cell division, cell differentiation, and morphogenesis. It focuses on the process of cell division (mitosis), which includes the phases of interphase, prophase, metaphase, anaphase, and telophase. Mitosis allows organisms to grow, repair damaged cells/tissues, replace dead cells, and reproduce in some organisms. It results in two identical daughter cells that are formed after the nucleus and cytoplasm divide.
The cell cycle consists of interphase and the M phase. Interphase includes G1, S, and G2 phases where the cell grows and duplicates its DNA. The M phase includes mitosis and cytokinesis where the cell divides into two identical daughter cells. Mitosis consists of prophase, prometaphase, metaphase, anaphase, and telophase where the duplicated chromosomes separate and a new nuclear membrane forms around each set of chromosomes. Cytokinesis then divides the cytoplasm.
Rai University provides high quality education for MSc, Law, Mechanical Engineering, BBA, MSc, Computer Science, Microbiology, Hospital Management, Health Management and IT Engineering.
The document discusses various types of retailers including specialty stores, department stores, supermarkets, convenience stores, and discount stores. It then covers marketing decisions for retailers related to target markets, product assortment, store services, pricing, promotion, and store location. The document also discusses wholesaling, including the functions of wholesalers, types of wholesalers, and marketing decisions faced by wholesalers.
This document discusses marketing channels and channel management. It defines marketing channels as sets of interdependent organizations that make a product available for use. Channels perform important functions like information gathering, stimulating purchases, negotiating prices, ordering, financing inventory, storage, and payment. Channel design considers customer expectations, objectives, constraints, alternatives that are evaluated. Channel management includes selecting, training, motivating, and evaluating channel members. Channels are dynamic and can involve vertical, horizontal, and multi-channel systems. Conflicts between channels must be managed to balance cooperation and competition.
The document discusses integrated marketing communication and its various elements. It defines integrated marketing communication as combining different communication modes like advertising, sales promotion, public relations, personal selling, and direct marketing to provide a complete communication portfolio to audiences. It also discusses the communication process and how each element of the marketing mix communicates to customers. The document provides details on the key components of an integrated marketing communication mix and how it can be used to build brand equity.
Pricing is a key element in determining the profitability and success of a business. The price must be set correctly - if too high, demand may decrease and the product may be priced out of the market, but if too low, revenue may not cover costs. Pricing strategies should consider the product lifecycle stage, costs, competitors, and demand factors. Common pricing methods include penetration pricing for new products, market skimming for premium products, value pricing based on perceived worth, and cost-plus pricing which adds a markup to costs. Price affects demand through price elasticity, with elastic demand more sensitive to price changes.
The document discusses various aspects of branding such as definitions of a brand, brand positioning, brand name selection, brand sponsorship, brand development strategies like line extensions and brand extensions, challenges in branding, importance of packaging, labeling, and universal product codes. It provides examples of well-known brands and analyzes their branding strategies. The key points covered are creating emotional value for customers, building relationships and loyalty, using brands to project aspirational lifestyles and values to command premium prices.
This document outlines the key stages in the new product development (NPD) process. It begins with generating ideas for new products, which can come from internal or external sources. Ideas are then screened using criteria like market size and development costs. Successful concepts are developed and test marketed to customers. If testing goes well, the product proceeds to commercialization with a full market launch. The NPD process helps companies focus their resources on projects most likely to be rewarding and brings new products to market more quickly. It describes common challenges in NPD like defining specifications and managing resources and timelines, and how to overcome them through planning and cross-functional involvement.
A product is an item offered for sale that can be physical or virtual. It has a life cycle and may need to be adapted over time to remain relevant. A product needs to serve a purpose, function well, and be effectively communicated to users. It also requires a name to help it stand out.
A product hierarchy has multiple levels from core needs down to specific items. These include the need, product family, class, line, type, and item or stock keeping unit.
Products go through a life cycle with stages of development, introduction, growth, maturity, and decline. Marketing strategies must adapt to each stage such as heavy promotion and price changes in introduction and maturity.
This document discusses barriers between marketing researchers and managerial decision makers. It identifies three types of barriers: behavioral, process, and organizational. Specific behavioral barriers discussed include confirmatory bias, the difficulty balancing creativity and data, and the newcomer syndrome. Process barriers include unsuccessful problem definition and research rigidity. Organizational barriers include misuse of information asymmetries. The document also discusses ethical issues in marketing research such as deceptive practices, invasion of privacy, and breaches of confidentiality.
The document discusses best practices for organizing, writing, and presenting a marketing research report. It provides guidance on structuring the report with appropriate headings, formatting the introduction and conclusion/recommendation sections, effectively utilizing visuals like tables and graphs, and tips for an ethical and impactful oral presentation of the findings. The goal is to clearly communicate the research results and insights to the client to inform their decision-making.
This document discusses marketing research and its key steps and methods. Marketing research involves collecting, analyzing and communicating information to make informed marketing decisions. There are 5 key steps in marketing research: 1) define the problem, 2) collect data, 3) analyze and interpret data, 4) reach a conclusion, 5) implement the research. Common data collection methods include interviews, surveys, observations, and experiments. The data is then analyzed using statistical techniques like frequency, percentages, and means to interpret the findings and their implications for marketing decisions.
Bdft ii, tmt, unit-iii, dyeing & types of dyeing,Rai University
Dyeing is a method of imparting color to textiles by applying dyes. There are two major types of dyes - natural dyes extracted from plants/animals/minerals and synthetic dyes made in a laboratory. Dyes can be applied at different stages of textile production from fibers to yarns to fabrics to finished garments. Common dyeing methods include stock dyeing, yarn dyeing, piece dyeing, and garment dyeing. Proper dye and method selection are needed for good colorfastness.
Bsc agri 2 pae u-4.4 publicrevenue-presentation-130208082149-phpapp02Rai University
The government requires public revenue to fund its political, social, and economic activities. There are three main sources of public revenue: tax revenue, non-tax revenue, and capital receipts. Tax revenue is collected through direct taxes like income tax, which are paid directly to the government, and indirect taxes like sales tax, where the burden can be shifted to other parties. Non-tax revenue sources include profits from public enterprises, railways, postal services, and the Reserve Bank of India. While taxes provide wide coverage and influence production, they can also reduce incentives to work and increase inequality.
Public expenditure has increasingly grown over time to fulfill three main roles: protecting society, protecting individuals, and funding public works. The growth can be attributed to several causes like increased income, welfare state ideology, effects of war, increased resources and ability to finance expenditures, inflation, and effects of democracy, socialism, and development. There are also canons that govern public spending like benefits, economy, and approval by authorities. The effects of public expenditure include impacts on consumption, production through efficiency, incentives and allocation, and distribution of resources.
Public finance involves the taxing and spending activities of government. It focuses on the microeconomic functions of government and examines taxes and spending. Government ideology can view the community or individual as most important. In the US, the federal government has more spending flexibility than states. Government spending has increased significantly as a percentage of GDP from 1929 to 2001. Major items of federal spending have shifted from defense to entitlements like Social Security and Medicare. Revenues mainly come from individual income taxes, payroll taxes, and corporate taxes at the federal level and property, sales, and income taxes at the state and local levels.
This document provides an overview of public finance. It defines public finance as the study of how governments raise money through taxes and spending, and how these activities affect the economy. It discusses why public finance is needed to provide public goods and services, redistribute wealth, and correct issues like pollution. The key aspects of public finance covered are government spending, revenue sources like income taxes, and how fiscal policy around spending and taxation can influence economic performance.
The document discusses the classical theory of inflation and how it relates to money supply. It states that inflation is defined as a rise in the overall price level in an economy. The quantity theory of money explains that inflation is primarily caused by increases in the money supply as controlled by the central bank. When the money supply grows faster than the amount of goods and services, it leads to too much money chasing too few goods and a rise in prices, or inflation. The document also notes that hyperinflation, which is a very high rate of inflation, can occur when governments print too much money to fund spending.
Bsc agri 2 pae u-3.2 introduction to macro economicsRai University
This document provides an introduction to macroeconomics. It defines macroeconomics as the study of national economies and the policies that governments use to affect economic performance. It discusses key issues macroeconomists address such as economic growth, business cycles, unemployment, inflation, international trade, and macroeconomic policies. It also outlines different macroeconomic theories including classical, Keynesian, and unified approaches.
Market structure identifies how a market is composed in terms of the number of firms, nature of products, degree of monopoly power, and barriers to entry. Markets range from perfect competition to pure monopoly based on imperfections. The level of competition affects consumer benefits and firm behavior. While models simplify reality, they provide benchmarks to analyze real world situations, where regulation may influence firm actions.
This document discusses the concept of perfect competition in economics. It defines perfect competition as a market with many small firms, identical products, free entry and exit of firms, and complete information. The document outlines the key features of perfect competition including: a large number of buyers and sellers, homogeneous products, no barriers to entry or exit, and profit maximization by firms. It also discusses the short run and long run equilibrium of a perfectly competitive firm, including cases where firms experience super normal profits, normal profits, or losses.
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
The technology uses reclaimed CO₂ as the dyeing medium in a closed loop process. When pressurized, CO₂ becomes supercritical (SC-CO₂). In this state CO₂ has a very high solvent power, allowing the dye to dissolve easily.
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptxMAGOTI ERNEST
Although Artemia has been known to man for centuries, its use as a food for the culture of larval organisms apparently began only in the 1930s, when several investigators found that it made an excellent food for newly hatched fish larvae (Litvinenko et al., 2023). As aquaculture developed in the 1960s and ‘70s, the use of Artemia also became more widespread, due both to its convenience and to its nutritional value for larval organisms (Arenas-Pardo et al., 2024). The fact that Artemia dormant cysts can be stored for long periods in cans, and then used as an off-the-shelf food requiring only 24 h of incubation makes them the most convenient, least labor-intensive, live food available for aquaculture (Sorgeloos & Roubach, 2021). The nutritional value of Artemia, especially for marine organisms, is not constant, but varies both geographically and temporally. During the last decade, however, both the causes of Artemia nutritional variability and methods to improve poorquality Artemia have been identified (Loufi et al., 2024).
Brine shrimp (Artemia spp.) are used in marine aquaculture worldwide. Annually, more than 2,000 metric tons of dry cysts are used for cultivation of fish, crustacean, and shellfish larva. Brine shrimp are important to aquaculture because newly hatched brine shrimp nauplii (larvae) provide a food source for many fish fry (Mozanzadeh et al., 2021). Culture and harvesting of brine shrimp eggs represents another aspect of the aquaculture industry. Nauplii and metanauplii of Artemia, commonly known as brine shrimp, play a crucial role in aquaculture due to their nutritional value and suitability as live feed for many aquatic species, particularly in larval stages (Sorgeloos & Roubach, 2021).
Phenomics assisted breeding in crop improvementIshaGoswami9
As the population is increasing and will reach about 9 billion upto 2050. Also due to climate change, it is difficult to meet the food requirement of such a large population. Facing the challenges presented by resource shortages, climate
change, and increasing global population, crop yield and quality need to be improved in a sustainable way over the coming decades. Genetic improvement by breeding is the best way to increase crop productivity. With the rapid progression of functional
genomics, an increasing number of crop genomes have been sequenced and dozens of genes influencing key agronomic traits have been identified. However, current genome sequence information has not been adequately exploited for understanding
the complex characteristics of multiple gene, owing to a lack of crop phenotypic data. Efficient, automatic, and accurate technologies and platforms that can capture phenotypic data that can
be linked to genomics information for crop improvement at all growth stages have become as important as genotyping. Thus,
high-throughput phenotyping has become the major bottleneck restricting crop breeding. Plant phenomics has been defined as the high-throughput, accurate acquisition and analysis of multi-dimensional phenotypes
during crop growing stages at the organism level, including the cell, tissue, organ, individual plant, plot, and field levels. With the rapid development of novel sensors, imaging technology,
and analysis methods, numerous infrastructure platforms have been developed for phenotyping.
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
Unlocking the mysteries of reproduction: Exploring fecundity and gonadosomati...AbdullaAlAsif1
The pygmy halfbeak Dermogenys colletei, is known for its viviparous nature, this presents an intriguing case of relatively low fecundity, raising questions about potential compensatory reproductive strategies employed by this species. Our study delves into the examination of fecundity and the Gonadosomatic Index (GSI) in the Pygmy Halfbeak, D. colletei (Meisner, 2001), an intriguing viviparous fish indigenous to Sarawak, Borneo. We hypothesize that the Pygmy halfbeak, D. colletei, may exhibit unique reproductive adaptations to offset its low fecundity, thus enhancing its survival and fitness. To address this, we conducted a comprehensive study utilizing 28 mature female specimens of D. colletei, carefully measuring fecundity and GSI to shed light on the reproductive adaptations of this species. Our findings reveal that D. colletei indeed exhibits low fecundity, with a mean of 16.76 ± 2.01, and a mean GSI of 12.83 ± 1.27, providing crucial insights into the reproductive mechanisms at play in this species. These results underscore the existence of unique reproductive strategies in D. colletei, enabling its adaptation and persistence in Borneo's diverse aquatic ecosystems, and call for further ecological research to elucidate these mechanisms. This study lends to a better understanding of viviparous fish in Borneo and contributes to the broader field of aquatic ecology, enhancing our knowledge of species adaptations to unique ecological challenges.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
Current Ms word generated power point presentation covers major details about the micronuclei test. It's significance and assays to conduct it. It is used to detect the micronuclei formation inside the cells of nearly every multicellular organism. It's formation takes place during chromosomal sepration at metaphase.
B.Sc. Microbiology/Biotech II Cell biology and Genetics Unit 2 cell cycle
1. Cell biology and genetics Unit 2
Cell cycle and Cancer
Rai University,
Ahmedabad
2. 2
Cell Division
All cells are derived from pre-
existing cells
New cells are produced for growth
and to replace damaged or old cells
Differs in prokaryotes (bacteria) and
eukaryotes (protists, fungi, plants, &
animals)
3. 3
Keeping Cells Identical
The instructions for
making cell parts are
encoded in the DNA, so
each new cell must get a
complete set of the DNA
molecules
4. 4
DNA Replication
DNA must be copied or
replicated before cell
division
Each new cell will then
have an identical copy
of the DNA
Original DNA
strand
Two new,
identical DNA
strands
1
6. 6
Prokaryotic Chromosome
The DNA of
prokaryotes
(bacteria) is one,
circular chromosome
attached to the
inside of the cell
membrane
3
7. 7
Eukaryotic Chromosomes
All eukaryotic cells store genetic information
in chromosomes
Most eukaryotes have between 10 and 50
chromosomes in their body cells
Human body cells have 46 chromosomes or 23
identical pairs
8. 8
Compacting DNA into Chromosomes
DNA is tightly
coiled around
proteins called
histones
4
9. 9
Chromosomes in Dividing Cells
Duplicated
chromosomes are
called chromatids &
are held together by
the centromere
Called Sister Chromatids
5
10. 10
Karyotype
A picture of the
chromosomes from a
human cell arranged in
pairs by size
First 22 pairs are called
autosomes
Last pair are the sex
chromosomes
XX female or XY male
12. 12
Types of Cell Reproduction
Asexual reproduction involves a single cell dividing to
make 2 new, identical daughter cells
Mitosis & binary fission are examples of asexual
reproduction
Sexual reproduction involves two cells (egg & sperm)
joining to make a new cell (zygote) that is NOT
identical to the original cells
Meiosis is an example
13. 13
Cell Division in Prokaryotes
Prokaryotes such as
bacteria divide into 2
identical cells by the
process of binary fission
Single chromosome makes
a copy of itself
Cell wall forms between
the chromosomes dividing
the cell
Parent cell
2 identical daughter cells
Chromosome
doubles
Cell splits
6
15. 15
Five Phases of the Cell Cycle
G1 - primary growth phase
S – synthesis; DNA replicated
G2 - secondary growth phase
collectively these 3 stages are called
interphase
M - mitosis
C - cytokinesis
16. 16
Interphase - G1 Stage
1st growth stage after cell division
Cells mature by making more
cytoplasm & organelles
Cell carries on its normal
metabolic activities
17. 7
Interphase – S Stage
Synthesis stage
DNA is copied or replicated
Two
identica
l copies
of DNA
Original
DNA
18. 18
Interphase – G2 Stage
2nd Growth Stage
Occurs after DNA has been copied
All cell structures needed for division are
made (e.g. centrioles)
Both organelles & proteins are synthesized
20. 20
Mitosis
Division of the nucleus
Also called karyokinesis
Only occurs in eukaryotes
Has four stages
Doesn’t occur in some cells
such as brain cells
8
21. 21
Early Prophase
Chromatin in nucleus condenses to form visible
chromosomes
Mitotic spindle forms from fibers in cytoskeleton
or centrioles (animal)
Chromosomes
22. 22
Late Prophase
Nuclear membrane & nucleolus are broken
down
Chromosomes continue condensing & are
clearly visible
Spindle fibers called kinetochores attach to the
centromere of each chromosome
Spindle finishes forming between the poles of
the cell
24. 24
Spindle Fibers
The mitotic spindle form from the microtubules in
plants and centrioles in animal cells
Polar fibers extend from one pole of the cell to the
opposite pole
Kinetochore fibers extend from the pole to the
centromere of the chromosome to which they attach
Asters are short fibers radiating from centrioles
25. 25
Metaphase
Chromosomes, attached to the kinetochore
fibers, move to the center of the cell
Chromosomes are now lined up at the equator
Pole of the
Cell
Equator of Cell
9
29. 29
Telophase
Sister chromatids at opposite poles
Spindle disassembles
Nuclear envelope forms around each set of
sister chromatids
Nucleolus reappears
CYTOKINESIS occurs
Chromosomes reappear as chromatin
31. 31
Cytokinesis
Means division of the cytoplasm
Division of cell into two, identical halves
called daughter cells
In plant cells, cell plate forms at the equator
to divide cell
In animal cells, cleavage furrow forms to
split cell
32. 32
Daughter Cells of Mitosis
Have the same number of chromosomes as
each other and as the parent cell from which
they were formed
Identical to each other, but smaller than
parent cell
Must grow in size to become mature cells (G1 of
Interphase)
33. 33
Eukaryotic Cell Division
Used for growth and repair
Produce two new cells
identical to the original cell
Cells are diploid (2n)
Chromosomes during Metaphase
of mitosis
Prophase Metaphase Anaphase Telophase Cytokinesis
12
35. 35
Uncontrolled Mitosis
If mitosis is not controlled,
unlimited cell division
occurs causing cancerous
tumors
Oncogenes are special
proteins that increase the
chance that a normal cell
develops into a tumor cell
Cancer cells
13
37. 37
Facts About Meiosis
Preceded by interphase which includes
chromosome replication
Two meiotic divisions --- Meiosis I and Meiosis
II
Called Reduction- division
Original cell is diploid (2n)
Four daughter cells produced that are
monoploid (1n)
38. 38
Facts About Meiosis
Daughter cells contain half the number of
chromosomes as the original cell
Produces gametes (eggs & sperm)
Occurs in the testes in males
(Spermatogenesis)
Occurs in the ovaries in females (Oogenesis)
39. 39
Start with 46 double stranded chromosomes (2n)
After 1 division - 23 double stranded chromosomes
(n)
After 2nd division - 23 single stranded chromosomes
(n)
Occurs in our germ cells that produce gametes
More Meiosis Facts
40. 40
Why Do we Need Meiosis?
It is the fundamental basis of sexual
reproduction
Two haploid (1n) gametes are brought
together through fertilization to form a
diploid (2n) zygote
41. 41
Replication of Chromosomes
Replication is the process
of duplicating a
chromosome
Occurs prior to division
Replicated copies are
called sister chromatids
Held together at
centromere
Occurs in
Interphase
14
42. 42
A Replicated Chromosome
Homologs
(same genes, different alleles)
Sister
Chromatids
(same genes,
same alleles)
Gene X
Homologs separate in meiosis I and therefore
different alleles separate.
43. 43
Meiosis Forms Haploid Gametes
Meiosis must reduce the chromosome number by
half
Fertilization then restores the 2n number
from mom from dad child
meiosis reduces
genetic content
too
much!
The right
number!
44. 44
Meiosis: Two Part Cell Division
Homologs
separate
Sister
chromatids
separate
Diploid
Meiosis
I
Meiosis
II
Diploid
Haploid
45. 45
Meiosis I: Reduction Division
Nucleus Spindle
fibers
Nuclear
envelope
Early Prophase I
(Chromosome
number doubled)
Late
Prophase I
Metaphase I
Anaphase I Telophase I
(diploid)
47. • Prophase I
• It is the longest phase of meiosis. During prophase I, DNA
is exchanged between homologous chromosomes in a
process called homologous recombination. This often
results in chromosomal crossover. The new combinations
of DNA created during crossover are a significant source
of genetic variation, and may result in beneficial new
combinations of alleles. The paired and replicated
chromosomes are called bivalents or tetrads, which have
two chromosomes and four chromatics, with one
chromosome coming from each parent. The process of
pairing the homologous chromosomes is called synapses.
At this stage, non-sister chromatids may cross-over at
points called chiasmata
47
48. 48
Tetrads Form in Prophase I
Homologous chromosomes
(each with sister chromatids)
Join to form a TETRAD
Called Synapsis
53. 53
Meiosis II
Only one homolog of each
chromosome is present in
the cell.
Meiosis II produces gametes with
one copy of each chromosome and thus
one copy of each gene.
Sister chromatids carry
identical genetic
information.
Gene X
59. 59
Results of Meiosis
Gametes (egg & sperm) form
Four haploid cells with one copy
of each chromosome
One allele of each gene
Different combinations of alleles
for different genes along the
chromosome
61. 61
Mitosis Meiosis
Number of divisions 1
2
Number of daughter
cells
2 4
Genetically identical? Yes No
Chromosome # Same as parent Half of parent
Where Somatic cells Germ cells
When Throughout life At sexual maturity
Role Growth and repair Sexual reproduction
Comparison of Divisions
63. Cell cycle regulation
• The timing and rates of cell division in different parts of an
animal or plant are Crucial for normal growth,
development, and maintenance.
• The frequency of cell division varies with cell type.
• Some human cells divide frequently throughout life (skin
cells), others have the ability to divide, but keep it in
reserve (liver cells), and mature nerve and muscle cells do
not appear to divide at all after maturity.
64. A molecular control system drives the cell
cycle
• The cell cycle appears to be driven by specific chemical
signals in the cytoplasm.
• Fusion of an S phase cell and a G1 phase cell induces the
G1 nucleus to start S phase.
• Fusion of a cell in mitosis with one in interphase induces
the second cell to enter mitosis
65. • The distinct events of the cell cycle are directed by a
distinct cell cycle control system.
• These molecules trigger and coordinate key events in the
cell cycle.
• The control cycle has a built-in clock, but it is also
regulated by external adjustments and internal controls.
66. Checkpoints of cell cycle
• A checkpoint in the cell cycle is a critical control point where stop and
go signals regulate the cycle.
• Three major checkpoints are found in the G1, G2, and M phases.
67. G1 Checkpoint
• For many cells, the G1 checkpoint, the restriction point in mammalian
cells, is the most important.
• If the cell receives a go-ahead signal, it usually completes the cell cycle
and divides.
• If it does not receive a go-ahead signal, the cell exits the cycle and
switches to a nondividing state, the G0 phase.
• Most human cells are in this phase.
• Liver cells can be “called back” to the cell cycle by external cues
(growth factors), but highly specialized nerve and muscle cells never
divide.
68. • Rhythmic fluctuations in the abundance and activity of control
molecules pace the cell cycle.
• Some molecules are protein kinases that activate or deactivate
other proteins by phosphorylating them.
• The levels of these kinases are present in constant amounts, but
these kinases require a second protein, a cyclin, to become activated.
• Levels of cyclin proteins fluctuate cyclically.
• The complex of kinases and cyclin forms cyclindependent kinases
(Cdks).
69. G2 Checkpoint
• The G2 checkpoint prevents cells from entering
mitosis when DNA is damaged
• Providing an opportunity for repair and stopping
the proliferation of damaged cells.
• G2 checkpoint helps to maintain genomic
stability, it is an important focus in understanding
the molecular causes of cancer.
70. Spindle assembly checkpoints
• During mitosis and meiosis, the spindle assembly checkpoint acts to
maintain genome stability by delaying cell division until accurate
chromosome segregation can be guaranteed.
• Accuracy requires that chromosomes become correctly attached to
the microtubule spindle apparatus via their kinetochores.
• When not correctly attached to the spindle, kinetochores activate the
spindle assembly checkpoint network, which in turn blocks cell cycle
progression.
• Once all kinetochores become stably attached to the spindle, the
checkpoint is inactivated, which alleviates the cell cycle block and
thus allows chromosome segregation and cell division to proceed.
71. Apoptosis
• Apoptosis, or programmed cell death, is a
normal occurrence in which an orchestrated
sequence of events leads to the death of a cell.
• Death by apoptosis is a neat, orderly process
characterized by the overall shrinkage in volume
of the cell and its nucleus, the loss of adhesion
to neighboring cells, the formation of blebs at the
cell surface, the dissection of the chromatin into
small fragments, and the rapid engulfment of the
“corpse” by phagocytosis.
72. • Because it is a safe and orderly process,
apoptosis might be compared to the
controlled implosion of a building using
carefully placed explosives as compared
to simply blowing up the structure without
concern for what happens to the flying
debris.
73. • It has been estimated that 1010–1011 cells
in the human body die every day by
apoptosis.
• For example, apoptosis is involved in the
elimination of cells that have sustained
irreparable genomic damage.