This document provides an overview of genetics and heredity. It begins with an introduction to genetics and heredity. It then discusses Mendel's experiments with pea plants which formed the basis of genetics and led to his laws of inheritance. The document describes cell structure and the cell cycle, including mitosis and meiosis. It explains DNA, chromosomes, genes, transcription and translation. The human genome project is also mentioned. Overall, the document covers the key concepts and history of genetics from its early discoveries to modern understanding of inheritance and DNA.
Genetics plays an important role in orthodontics and malocclusion. The document discusses the history of genetics from Mendel's laws to modern discoveries. It describes DNA, genes, and how they are regulated. Genetic factors influence craniofacial development and conditions like cleft lip/palate. Different malocclusions such as Class II and Class III may have genetic or environmental causes. Overall, the document provides an overview of genetics and its relevance to orthodontics and malocclusion etiology.
This document discusses genetics and orthodontics. It covers the history of genetics, basic genetic terminology like DNA and genes. It discusses Mendel's laws of inheritance and how DNA is replicated. Part two will cover topics like homeobox genes, twin studies, and the genetics behind malocclusion, tooth agenesis, and other dental issues. Homeobox genes like Msx, Dlx, and Lhx play important roles in craniofacial development and patterning of the dentition. Mutations in these genes can lead to issues like cleft lip and palate.
This document provides an overview of the history and key developments in genetics and its relationship to orthodontics. It begins with Gregor Mendel's discoveries in 1866 laying the foundations of genetics. Major milestones include the discovery of DNA structure in the 1950s and determining the genetic code in 1966. Advances enabled genetic engineering, cloning, and the Human Genome Project. The document discusses cellular and molecular components involved in inheritance including DNA, genes, mutations. It examines genetic transmission patterns and disorders relevant to orthodontics like cleft lip/palate. Twin and pedigree studies are described as methods to study genetic influences on traits.
The document provides an overview of basic genetics concepts:
1) DNA is stored in chromosomes in the nucleus and contains genetic instructions in the form of genes that are made up of sequences of nucleotide base pairs.
2) DNA gets packaged into chromosomes through coiling and histone proteins for efficient storage in the nucleus.
3) The order of base pairs in genes determines the sequence of amino acids that make up proteins, which influence traits. Inherited genetic mutations can cause genetic disorders.
Basic genetics /certified fixed orthodontic courses by Indian dental academy Indian dental academy
Welcome to Indian Dental Academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy has a unique training program & curriculum that provides students with exceptional clinical skills and enabling them to return to their office with high level confidence and start treating patients
State of the art comprehensive training-Faculty of world wide repute &Very affordable.
The document discusses various concepts related to genetics and genes. It defines key terms like DNA, mRNA, gene, coding region, exons, introns, regulatory sequences, alleles, loci, genotype, phenotype, traits, karyotype and more. It explains genes are segments of DNA that encode instructions to make proteins, while regulatory sequences control gene expression. mRNA carries gene copies from DNA in the nucleus to cellular machinery for protein production.
This presentation elaborates regarding introduction to genetics, chromosomes, DNA, RNA, Genetics of developmental disorders of teeth, Genetics of craniofacial disorders and syndromes, genetics of cleft lip and palate, malocclusion and dental caries
Genetics plays an important role in orthodontics and malocclusion. The document discusses the history of genetics from Mendel's laws to modern discoveries. It describes DNA, genes, and how they are regulated. Genetic factors influence craniofacial development and conditions like cleft lip/palate. Different malocclusions such as Class II and Class III may have genetic or environmental causes. Overall, the document provides an overview of genetics and its relevance to orthodontics and malocclusion etiology.
This document discusses genetics and orthodontics. It covers the history of genetics, basic genetic terminology like DNA and genes. It discusses Mendel's laws of inheritance and how DNA is replicated. Part two will cover topics like homeobox genes, twin studies, and the genetics behind malocclusion, tooth agenesis, and other dental issues. Homeobox genes like Msx, Dlx, and Lhx play important roles in craniofacial development and patterning of the dentition. Mutations in these genes can lead to issues like cleft lip and palate.
This document provides an overview of the history and key developments in genetics and its relationship to orthodontics. It begins with Gregor Mendel's discoveries in 1866 laying the foundations of genetics. Major milestones include the discovery of DNA structure in the 1950s and determining the genetic code in 1966. Advances enabled genetic engineering, cloning, and the Human Genome Project. The document discusses cellular and molecular components involved in inheritance including DNA, genes, mutations. It examines genetic transmission patterns and disorders relevant to orthodontics like cleft lip/palate. Twin and pedigree studies are described as methods to study genetic influences on traits.
The document provides an overview of basic genetics concepts:
1) DNA is stored in chromosomes in the nucleus and contains genetic instructions in the form of genes that are made up of sequences of nucleotide base pairs.
2) DNA gets packaged into chromosomes through coiling and histone proteins for efficient storage in the nucleus.
3) The order of base pairs in genes determines the sequence of amino acids that make up proteins, which influence traits. Inherited genetic mutations can cause genetic disorders.
Basic genetics /certified fixed orthodontic courses by Indian dental academy Indian dental academy
Welcome to Indian Dental Academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy has a unique training program & curriculum that provides students with exceptional clinical skills and enabling them to return to their office with high level confidence and start treating patients
State of the art comprehensive training-Faculty of world wide repute &Very affordable.
The document discusses various concepts related to genetics and genes. It defines key terms like DNA, mRNA, gene, coding region, exons, introns, regulatory sequences, alleles, loci, genotype, phenotype, traits, karyotype and more. It explains genes are segments of DNA that encode instructions to make proteins, while regulatory sequences control gene expression. mRNA carries gene copies from DNA in the nucleus to cellular machinery for protein production.
This presentation elaborates regarding introduction to genetics, chromosomes, DNA, RNA, Genetics of developmental disorders of teeth, Genetics of craniofacial disorders and syndromes, genetics of cleft lip and palate, malocclusion and dental caries
Basic genetics ,mutation and karyotypingAamir Sharif
This document provides an overview of genetics and defines key genetic concepts. It discusses that genetics is the study of heredity and the variation of traits among organisms. It describes that DNA contains the genetic code and is made up of nucleotides with four bases that pair up in a double helix structure. Genes are sections of DNA that code for proteins. Chromosomes package DNA and humans have 23 chromosome pairs. Mutations can occur that change DNA sequences and cause genetic disorders. The document outlines different types of mutations and explains genetic testing techniques like karyotyping to analyze chromosomes for abnormalities.
This document discusses eukaryotic chromosome organization. It notes that eukaryotic cells contain many chromosomes in the nucleus, with each species having a characteristic number. Chromosomes are made up of DNA and proteins like histones. DNA is wrapped around histones to form structures called nucleosomes, which are further compacted through multiple levels of coiling and folding involving other proteins. This allows the long DNA molecules to fit within cell nuclei.
The document discusses the physical and chemical basis of heredity. It explains that genes, which reside on chromosomes, are the carriers of hereditary information from one generation to the next. The DNA portion of genes functions as the chemical basis of heredity. Chromosomes are composed of DNA and contain many genes. They are visualized during cell division. The number of chromosomes is consistent within species but can vary between species. Mitosis and meiosis distribute genetic material during cell division and gamete formation, respectively. Nucleic acids and proteins serve as the molecular basis of genetics, with DNA containing genetic information that is transcribed into RNA and translated into proteins.
Eukaryotic and Prokaryotic Chromosomes Eukaryotic and Prokaryotic Chromosomes Eukaryotic and Prokaryotic Chromosomes Eukaryotic and Prokaryotic Chromosomes Eukaryotic and Prokaryotic Chromosomes Eukaryotic and Prokaryotic Chromosomes Eukaryotic and Prokaryotic Chromosomes
CYTOPLASMIC INHERITANCE WITH REFERENCETO MITOCHONDRIAL INHERITANCE IN YEASTBishnuPatra1
This document summarizes a presentation on cytoplasmic inheritance with reference to mitochondrial inheritance in yeast. It discusses how cytoplasmic inheritance transmits genes outside the nucleus, usually from the female parent. Mitochondria contain their own circular DNA called mt-DNA. Mitochondrial inheritance refers to traits encoded in the mitochondrial genome being inherited, generally from the female parent. The document uses petite mutations in yeast mitochondria as an example, describing three types of petite mutants: 1) Segregational petite mutants created by nuclear mutations that segregate mendelianly, 2) Neutral petite mutants whose offspring are wild type when crossed with wild type yeast, and 3) Suppressive petite mutants that dominate and suppress wild type mitochondrial function in offspring
As a periodontist, it is of utmost importance to understand the genetic basis of inheritance in periodontal diseases be able to relate to the various polymorphisms associated with periodontal diseases. This ppt presents the basics of genetics from the point of view of future understanding of polymorphisms related to periodontal diseases.
Chromosomes /certified fixed orthodontic courses by Indian dental academy Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
Genes, Chromosomes and Genetic Code: Relevance and ImplicationsJen Gragera
The document discusses genetic disorders including chromosomal abnormalities, single gene disorders, and multifactorial disorders. It describes how chromosomal abnormalities can involve extra or missing chromosomes and structural changes. Single gene disorders can be inherited in autosomal dominant, autosomal recessive, X-linked, Y-linked, or mitochondrial patterns. Multifactorial disorders involve multiple genes and environmental factors. The document also discusses genetic testing and prevention of some birth defects.
Genitics and malocclusion /certified fixed orthodontic courses by Indian de...Indian dental academy
This document provides an overview of genetics and its relationship to malocclusion. It begins with a brief history of genetics, covering early proposals by Maupertuis and Mendel's foundational work with pea plants. It then discusses key genetic concepts like DNA, genes, chromosomes, mutations and inheritance patterns. The document reviews twin and family studies on the heritability of tooth size, morphology and dental phenotypes. It also mentions craniofacial syndromes and concludes that the influence of genetics versus environment on malocclusion has long been debated.
Chromosomes are rod-shaped structures found in the nucleus of cells that carry genetic information in the form of DNA. They were first described in 1875 and are visible during cell division. Chromosomes exist in two types - autosomes which control non-sex characteristics, and sex chromosomes which determine sex. Each chromosome has a centromere, short and long arms, and telomeres at the ends. The number of chromosomes varies between species but cells of an individual normally contain an even number of matched chromosomes. Chromatin is the combination of DNA and proteins that packages DNA within the nucleus, and exists in either loosely coiled euchromatin form or tightly coiled heterochromatin form.
For all the UG and PG courses in Biotechnology, Microbiology Genetics and other Life Science students. This ppt is about the Y chromosome and its unusual structure in the human genome.
Genetics is the study of heredity and variation. It examines how traits are inherited through genes on chromosomes, which are faithfully transmitted from parents to offspring via gametes, maintaining generational continuity. Genetic variation arises from mutations in the DNA sequence, which are heritable changes that provide the basis for natural selection and evolution. Genetics also explores DNA and gene function at the molecular level using techniques like restriction enzymes, vectors, recombinant DNA, and cloning.
HUMAN CHROMOSOMAL ABERRATIONS AND KARYOTYPE ANALYSIS.Shylesh M
Chromosomal aberrations refer to changes in chromosome structure or number. The document discusses various types of structural aberrations like deletions, duplications, inversions, and translocations, and numerical aberrations involving changes in ploidy. Karyotype analysis involves staining and arranging chromosomes to identify aberrations. Abnormal karyotypes can lead to diseases like Down syndrome, Patau syndrome, and Cri du chat syndrome. The normal human karyotype contains 22 pairs of autosomes and an XX or XY sex chromosome complement.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Genes, Chromosomes, and Genetic Code: Relevance and ImplicationsJen Gragera
Genes are the thing that determines your unique traits from the inside out. They play an important role in your overall health but they can also make you more susceptible for certain health problems and diseases, in the first place those that run in your family. Most diseases are a result of a combination of multiple factors including dietary, lifestyle and environmental factors. However, it is also possible to develop health problems exclusively due to genetic abnormalities and mutations.
Basic concepts of Genes, Chromosomes & DNA: Human Genome ProjectAnamika Ramawat
The document discusses the basic concepts of genetics including DNA, genes, chromosomes, and genetic inheritance. It provides definitions of key terms like gene, allele, and chromosome. It also summarizes the goals and accomplishments of the Human Genome Project, which aimed to map the entire human genome to better understand genes and hereditary traits.
This document discusses DNA, its structure and role in storing genetic information. It describes the processes of DNA replication, transcription and translation which produce proteins from DNA code. It also summarizes the stages of mitosis and meiosis, the two types of cell division. Mitosis produces identical body cells while meiosis reduces chromosome number producing gametes like eggs and sperm.
Group E's document discusses DNA, its structure and role in storing genetic information. It describes DNA replication that occurs during cell division. The processes of transcription and translation are explained, where DNA is transcribed into mRNA which is then translated into proteins. Mitosis and meiosis are summarized, including their key stages and roles in cell division and gamete formation. Meiosis specifically reduces chromosome number through two cell divisions. Key terms like chromosomes, chromatids, and kinetochores are defined in the context of cell division.
Basic genetics ,mutation and karyotypingAamir Sharif
This document provides an overview of genetics and defines key genetic concepts. It discusses that genetics is the study of heredity and the variation of traits among organisms. It describes that DNA contains the genetic code and is made up of nucleotides with four bases that pair up in a double helix structure. Genes are sections of DNA that code for proteins. Chromosomes package DNA and humans have 23 chromosome pairs. Mutations can occur that change DNA sequences and cause genetic disorders. The document outlines different types of mutations and explains genetic testing techniques like karyotyping to analyze chromosomes for abnormalities.
This document discusses eukaryotic chromosome organization. It notes that eukaryotic cells contain many chromosomes in the nucleus, with each species having a characteristic number. Chromosomes are made up of DNA and proteins like histones. DNA is wrapped around histones to form structures called nucleosomes, which are further compacted through multiple levels of coiling and folding involving other proteins. This allows the long DNA molecules to fit within cell nuclei.
The document discusses the physical and chemical basis of heredity. It explains that genes, which reside on chromosomes, are the carriers of hereditary information from one generation to the next. The DNA portion of genes functions as the chemical basis of heredity. Chromosomes are composed of DNA and contain many genes. They are visualized during cell division. The number of chromosomes is consistent within species but can vary between species. Mitosis and meiosis distribute genetic material during cell division and gamete formation, respectively. Nucleic acids and proteins serve as the molecular basis of genetics, with DNA containing genetic information that is transcribed into RNA and translated into proteins.
Eukaryotic and Prokaryotic Chromosomes Eukaryotic and Prokaryotic Chromosomes Eukaryotic and Prokaryotic Chromosomes Eukaryotic and Prokaryotic Chromosomes Eukaryotic and Prokaryotic Chromosomes Eukaryotic and Prokaryotic Chromosomes Eukaryotic and Prokaryotic Chromosomes
CYTOPLASMIC INHERITANCE WITH REFERENCETO MITOCHONDRIAL INHERITANCE IN YEASTBishnuPatra1
This document summarizes a presentation on cytoplasmic inheritance with reference to mitochondrial inheritance in yeast. It discusses how cytoplasmic inheritance transmits genes outside the nucleus, usually from the female parent. Mitochondria contain their own circular DNA called mt-DNA. Mitochondrial inheritance refers to traits encoded in the mitochondrial genome being inherited, generally from the female parent. The document uses petite mutations in yeast mitochondria as an example, describing three types of petite mutants: 1) Segregational petite mutants created by nuclear mutations that segregate mendelianly, 2) Neutral petite mutants whose offspring are wild type when crossed with wild type yeast, and 3) Suppressive petite mutants that dominate and suppress wild type mitochondrial function in offspring
As a periodontist, it is of utmost importance to understand the genetic basis of inheritance in periodontal diseases be able to relate to the various polymorphisms associated with periodontal diseases. This ppt presents the basics of genetics from the point of view of future understanding of polymorphisms related to periodontal diseases.
Chromosomes /certified fixed orthodontic courses by Indian dental academy Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
Genes, Chromosomes and Genetic Code: Relevance and ImplicationsJen Gragera
The document discusses genetic disorders including chromosomal abnormalities, single gene disorders, and multifactorial disorders. It describes how chromosomal abnormalities can involve extra or missing chromosomes and structural changes. Single gene disorders can be inherited in autosomal dominant, autosomal recessive, X-linked, Y-linked, or mitochondrial patterns. Multifactorial disorders involve multiple genes and environmental factors. The document also discusses genetic testing and prevention of some birth defects.
Genitics and malocclusion /certified fixed orthodontic courses by Indian de...Indian dental academy
This document provides an overview of genetics and its relationship to malocclusion. It begins with a brief history of genetics, covering early proposals by Maupertuis and Mendel's foundational work with pea plants. It then discusses key genetic concepts like DNA, genes, chromosomes, mutations and inheritance patterns. The document reviews twin and family studies on the heritability of tooth size, morphology and dental phenotypes. It also mentions craniofacial syndromes and concludes that the influence of genetics versus environment on malocclusion has long been debated.
Chromosomes are rod-shaped structures found in the nucleus of cells that carry genetic information in the form of DNA. They were first described in 1875 and are visible during cell division. Chromosomes exist in two types - autosomes which control non-sex characteristics, and sex chromosomes which determine sex. Each chromosome has a centromere, short and long arms, and telomeres at the ends. The number of chromosomes varies between species but cells of an individual normally contain an even number of matched chromosomes. Chromatin is the combination of DNA and proteins that packages DNA within the nucleus, and exists in either loosely coiled euchromatin form or tightly coiled heterochromatin form.
For all the UG and PG courses in Biotechnology, Microbiology Genetics and other Life Science students. This ppt is about the Y chromosome and its unusual structure in the human genome.
Genetics is the study of heredity and variation. It examines how traits are inherited through genes on chromosomes, which are faithfully transmitted from parents to offspring via gametes, maintaining generational continuity. Genetic variation arises from mutations in the DNA sequence, which are heritable changes that provide the basis for natural selection and evolution. Genetics also explores DNA and gene function at the molecular level using techniques like restriction enzymes, vectors, recombinant DNA, and cloning.
HUMAN CHROMOSOMAL ABERRATIONS AND KARYOTYPE ANALYSIS.Shylesh M
Chromosomal aberrations refer to changes in chromosome structure or number. The document discusses various types of structural aberrations like deletions, duplications, inversions, and translocations, and numerical aberrations involving changes in ploidy. Karyotype analysis involves staining and arranging chromosomes to identify aberrations. Abnormal karyotypes can lead to diseases like Down syndrome, Patau syndrome, and Cri du chat syndrome. The normal human karyotype contains 22 pairs of autosomes and an XX or XY sex chromosome complement.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Genes, Chromosomes, and Genetic Code: Relevance and ImplicationsJen Gragera
Genes are the thing that determines your unique traits from the inside out. They play an important role in your overall health but they can also make you more susceptible for certain health problems and diseases, in the first place those that run in your family. Most diseases are a result of a combination of multiple factors including dietary, lifestyle and environmental factors. However, it is also possible to develop health problems exclusively due to genetic abnormalities and mutations.
Basic concepts of Genes, Chromosomes & DNA: Human Genome ProjectAnamika Ramawat
The document discusses the basic concepts of genetics including DNA, genes, chromosomes, and genetic inheritance. It provides definitions of key terms like gene, allele, and chromosome. It also summarizes the goals and accomplishments of the Human Genome Project, which aimed to map the entire human genome to better understand genes and hereditary traits.
This document discusses DNA, its structure and role in storing genetic information. It describes the processes of DNA replication, transcription and translation which produce proteins from DNA code. It also summarizes the stages of mitosis and meiosis, the two types of cell division. Mitosis produces identical body cells while meiosis reduces chromosome number producing gametes like eggs and sperm.
Group E's document discusses DNA, its structure and role in storing genetic information. It describes DNA replication that occurs during cell division. The processes of transcription and translation are explained, where DNA is transcribed into mRNA which is then translated into proteins. Mitosis and meiosis are summarized, including their key stages and roles in cell division and gamete formation. Meiosis specifically reduces chromosome number through two cell divisions. Key terms like chromosomes, chromatids, and kinetochores are defined in the context of cell division.
Cellular reproduction occurs through mitosis and meiosis. Mitosis involves nuclear division to produce two daughter cells with identical DNA. Meiosis involves two nuclear divisions and produces four haploid gametes. During meiosis I, homologous chromosomes pair and may exchange genetic material through crossing over. This reduces the chromosome number from diploid to haploid. Meiosis II then separates the sister chromatids, resulting in four unique haploid cells that can fuse during fertilization.
The document describes the cell cycle and its various phases. It begins by defining the cell cycle as the sequence of events a cell undergoes from formation after division of a parent cell until its own division into daughter cells. The cell cycle consists of interphase and the M phase. Interphase includes the G1, S, and G2 phases where the cell grows and duplicates its DNA. The M phase encompasses mitosis and cytokinesis where the cell divides into two daughter cells. Meiosis is also discussed, which produces gametes through two cell divisions and a reduction in chromosome number from diploid to haploid.
Meiosis is a type of cell division that produces haploid gametes from a diploid cell. It involves two rounds of nuclear division and cell division. In meiosis I, homologous chromosomes pair and separate, reducing the chromosome number by half. Meiosis II separates sister chromatids, resulting in four haploid daughter cells each with half the number of chromosomes as the original parent cell. The key stages of meiosis I are prophase I, metaphase I, anaphase I and telophase I, followed by cytokinesis. Prophase I is the longest phase and involves further substages of leptotene, zygotene, pachytene, diplotene and diakinesis.
Mitosis and meiosis are two types of cell division that occur in eukaryotic organisms. Mitosis produces two identical daughter cells from a single parent cell, while meiosis produces four haploid daughter cells from a single diploid parent cell. The key differences are that mitosis results in cells with the same number of chromosomes as the parent cell, while meiosis reduces the chromosome number by half to produce gametes. Meiosis has two rounds of nuclear division - meiosis I and meiosis II - while mitosis only has one.
This document summarizes a presentation on cell division, genetic mutation, and the law of inheritance. It defines genetics and describes the cell cycle, mitosis, meiosis, genetic mutation, and Mendel's laws of inheritance. It explains cell division processes like prophase, metaphase, anaphase, and telophase. It also discusses genetic disorders like fragile X syndrome and how environmental factors like radiation and chemicals can cause genetic mutations.
Meiosis is a two-step cell division process that produces gametes with half the normal number of chromosomes. It consists of Meiosis I, which separates homologous chromosome pairs, and Meiosis II, which separates sister chromatids. This results in four haploid daughter cells from one original diploid cell. The document provides details on the stages of meiosis, including prophase I with chromosome pairing and crossing over, and discusses how meiosis contributes to genetic diversity.
The document discusses cellular reproduction and the cell cycle. It explains that cells require genetic instructions from DNA to survive and divide. There are two main types of cells - prokaryotic and eukaryotic. Eukaryotic cells undergo mitotic cell division, which involves interphase where DNA is replicated, followed by mitosis where the cell divides into two identical daughter cells through nuclear division and cytoplasmic division. Mitosis ensures each daughter cell receives a complete copy of genetic material and maintains chromosome number.
The nucleus is the command center of the cell, containing DNA and machinery to replicate DNA and synthesize proteins. It is enclosed by a double membrane and contains chromatin (DNA and proteins), nucleoli, and other components. Chromatin contains DNA wound around histone proteins and exists in two forms - euchromatin (loosely packed) and heterochromatin (tightly packed). The nucleolus produces ribosomal subunits. The nucleus ensures cellular activities are regulated and directs production of proteins and ribosomes. During cell division, DNA is replicated and chromosomes segregate into daughter cells through the phases of mitosis or meiosis.
Cell division occurs through mitosis or meiosis. Mitosis produces two identical daughter cells from one parent cell during growth and repair. Meiosis produces four haploid gametes from one diploid cell during gametogenesis. During meiosis, homologous chromosomes pair up and may exchange genetic material through crossing over, resulting in genetic diversity among gametes. The two divisions of meiosis and the independent assortment of chromosomes ensure each gamete has a unique combination of the parental chromosomes.
The document provides an overview of nuclear structure and function. It discusses the nucleus, nuclear envelope, nucleolus, chromatin, DNA replication and transcription processes. It describes chromosomal structure including centromeres, telomeres, and histones. It covers chromosomal abnormalities like deletions, duplications, inversions, insertions, and translocations. It discusses the Philadelphia chromosome translocation in CML cells. It also summarizes chromosomal karyotyping, the cell cycle phases of interphase and cell division, and mitosis and cytokinesis.
Chromosomes are structures located in the nucleus that contain DNA. They carry genetic instructions that are passed down from parents to offspring. Chromosomes vary in number between species and contain genes. During cell division, the chromosome duplicates and divides equally between the two new cells through the process of mitosis. Telomeres protect the ends of chromosomes and shorten each time a cell divides. When telomeres become too short, the cell can no longer replicate and dies.
AS Level Biology - 5/6) Mitotic Cell Cycle and Protein SynthesisArm Punyathorn
The mitotic cell cycle and the synthesis of proteins by DNA transcription and translation is one of the most puzzling processes in Biology. It is such a fundamental process for life and yet its true mechanism may still be a mystery. However, the fascinating complexity makes it one of the most interesting topics to study in Biology.
This document discusses cell structures and functions including the nucleus, nucleolus, chromosomes, and genes. It describes the nucleus as the control center that contains nucleoplasm, chromosomes, and nucleoli. Genes are segments of DNA located on chromosomes. The document also discusses nucleic acids DNA and RNA, transcription, translation, cell division through mitosis and meiosis, and their purposes. Mitosis produces two identical daughter cells while meiosis results in four non-identical haploid cells. The cell cycle, stages of mitosis and meiosis, and why each occurs are summarized.
The document summarizes the cell cycle process of mitosis and meiosis. It describes that the cell cycle consists of interphase and mitosis or meiosis. Interphase is divided into G1, S, and G2 phases where the cell grows and duplicates its contents in preparation for division. Mitosis is the process where the cell nucleus divides into two identical nuclei through the stages of prophase, metaphase, anaphase and telophase. Meiosis produces gametes through two cell divisions and involves homologous chromosome pairing, crossing over and separation into haploid cells with one chromosome of each type.
The document summarizes the cell cycle process of mitosis and meiosis. It describes that the cell cycle consists of interphase and mitosis or meiosis. Interphase is divided into G1, S, and G2 phases where the cell grows and duplicates its contents in preparation for division. Mitosis is the process where the cell nucleus divides into two identical nuclei through the stages of prophase, metaphase, anaphase and telophase. Meiosis produces gametes through two cell divisions and involves homologous chromosome pairing, crossing over and separation into haploid cells with one chromosome of each type.
The document summarizes the cell cycle process of mitosis and meiosis. It describes that the cell cycle consists of interphase, where the cell grows and organelles double, followed by either mitosis or meiosis. Mitosis involves the division of the nucleus into two identical daughter cells through the stages of prophase, metaphase, anaphase and telophase. Meiosis results in four haploid daughter cells through two rounds of division, including homologous chromosome pairing and separation in meiosis I and sister chromatid separation in meiosis II.
The document summarizes the cell cycle process of mitosis and meiosis. It describes that the cell cycle consists of interphase and mitosis or meiosis. Interphase is divided into G1, S, and G2 phases where the cell grows and duplicates its contents in preparation for division. Mitosis is the process where the cell nucleus divides into two identical nuclei through the stages of prophase, metaphase, anaphase and telophase. Meiosis produces gametes through two cell divisions and involves homologous chromosome pairing, crossing over and separation into haploid cells with one chromosome of each type.
The document summarizes the cell cycle process of mitosis and meiosis. It describes that the cell cycle consists of interphase and mitosis or meiosis. Interphase is divided into G1, S, and G2 phases where the cell grows and duplicates its contents in preparation for division. Mitosis is then described as the process where the cell nucleus divides into two identical nuclei through the stages of prophase, metaphase, anaphase and telophase. Meiosis is then summarized as the process that forms gametes through two cell divisions, reducing the chromosome number by half to produce four haploid cells from one original diploid cell.
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.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
The simplified electron and muon model, Oscillating Spacetime: The Foundation...RitikBhardwaj56
Discover the Simplified Electron and Muon Model: A New Wave-Based Approach to Understanding Particles delves into a groundbreaking theory that presents electrons and muons as rotating soliton waves within oscillating spacetime. Geared towards students, researchers, and science buffs, this book breaks down complex ideas into simple explanations. It covers topics such as electron waves, temporal dynamics, and the implications of this model on particle physics. With clear illustrations and easy-to-follow explanations, readers will gain a new outlook on the universe's fundamental nature.
How to Fix the Import Error in the Odoo 17Celine George
An import error occurs when a program fails to import a module or library, disrupting its execution. In languages like Python, this issue arises when the specified module cannot be found or accessed, hindering the program's functionality. Resolving import errors is crucial for maintaining smooth software operation and uninterrupted development processes.
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How to Make a Field Mandatory in Odoo 17Celine George
In Odoo, making a field required can be done through both Python code and XML views. When you set the required attribute to True in Python code, it makes the field required across all views where it's used. Conversely, when you set the required attribute in XML views, it makes the field required only in the context of that particular view.
2. Contents
• Introduction
• Beginning of genetics
• Cell
• DNA
• Chromosomes & Genes
• Inheritance
• Twin studies
• Influence of genetics in malocclusion
• Human genome project
• Conclusion
3. Introduction
Genetics -The branch of biology which deals
primarily with the principles of heredity &
variation, & secondarily with the role of
environmental factors as they interact with genes
in the development of an individual.
Heredity -It can be defined as that force of nature
which permits the transmission of characteristics
of a species from generation to generation .
4. Beginning of genetics
Mendelism - Story of genetics really starts with the
work of Gregor Johann Mendel, a monk in
Moravia. He was born on July 22, 1822.
He made his discoveries by analysis of results
after crossing varieties of Garden pea
(Pisumsativum)
He took – round or wrinkled seeds,tall or dwarf
plant, violet or white flowers.He crossed varieties
differing only in one pair of these characteristics.
6. Mendel’s laws:
• Law of Uniformity –When 2 homozygotes with
different alleles are crossed all of the off springs
of first generation are identical heterozygotes.
• Law of Seggration –Each individual possess 2
factors which determine specific characteristic, a
parent transmits only 1 of these factors to any
particular off spring.It is purely a matter of chance
which of the 2 factors get transmitted.
7. Punnett’s square showing different ways in which
genes can segregate and combine in second
generation cross.
Male Gametes
FemaleGametes
T t
T
t
TT Tt
Tt tt
8. • Law of Independent assortment –
Independent assortment occurs only when
genes affecting different characters are on
different chromosomes. In other words genes
that are not alleles are distributed to gametes
independently to each other.
9. Cell structure & division
Cell-Basic unit of life
• cytoplasm
• nucleus
• cell membrane
• cell organelles
12. • In G1 phase chromosomes become thin and
extended. This phase of cycle is very variable
in length and is responsible for the variation in
generation time between different cell
population .
• The phase between successive mitoses is
known as the interphase of the cell cycle. In
rapidly dividing cells this last for between 16
to 24 hours.
13. • Interphase is completed by relatively short
G2 phase during which the chromosomes
begin condense in preparation for the next
mitotic division.
•The G1 Phase is followed by S phase i.e
synthesis when DNA replication occurs and
the chromatin of each chromosome is
replicated.
14. Cell division
Mitosis
Meiosis
In mitosis a cell gives rise to 2 daughter cells
which are identical to the parent cell, in this
the daughter cell receives the complete
chromosome set as the parent.
In meiosis there is reduction in the number of
chromosomes to half, this process is carried
out in gametogenesis .
15. Mitosis
• Prophase –In this phase chromosomes can be
seen easily . The two chromatids are seen,
centrioles duplicates itself and each one
migrates to opposite poles of cell.
• Metaphase – During this phase
chromosomes are maximally contracted,
they aligned along the equatorial plane
,where each chromosomes is attached to
centioles by microtubles forming the mature
spindles.
16. • Anaphase – Centromere of each chromosomes
divides longitudinally and the two daughter
chromatids seperates to opposite poles.
• Telophase- The daughter chromosomes arrive at
the poles of the cell. Cytokinesis occur at this
stage. Chromosomes unwind and get enclosed in
nuclear membrane and the cell division is
completed.
17.
18. Meiosis
It takes place in 2 phase-
Meiosis I
Meiosis II
This takes place when the gamets are
formed, number of the each chromosomes get
halved and each gamete receiving only haploid
set of chromosomes.
19. Prophase I- Leptotene
- Zygotene
- Pachytene
- Diplotene
- Diakinesis
Metaphase I
Anaphase I
Telophase I
Meiosis I
Meiosis II- an ordinary mitosis,without DNA
replication
20. Prophase I
Leptotene- Chromosomes appear as long,
slender threads with many bead like structures
(chromomeres) along their length.
Zygotene – Homologous chromosomes appear
to attract each other and enter into a very close
zipper like pairing (synapsis), pairing is highly
specific.
Pachytene – Each pair of homologous
chromosomes known as a bivalent ,become
tightly coiled. Crossing over occur during
homologous region of DNA are exchanged
between chromatids.
21. • Diplotene – Distinctly visible separation occurs
between homologous chromosomes except for
specific regions known as chiasmata where an
actual crossing over has taken place .These
crossed areas are X shaped attachments between
the chromosomes and is the only remaining
force holding each bivalent together until
metaphase.
• Diakinesis – Seperation of homologous
chromosome pairs proceeds as the chromosomes
becomes maximally condensed.
22. MetaphaseI-Nuclear membrane disappears
and the chromosomes become aligned on the
equatorial plane of the cell where they have
become attached to the spindle, as in
metaphase of mitosis.
Anaphase I - one entire chromosome of the
pair move to either pole.
23. Telophase I- Each set of haploid chromosomes
have completely seperated to opposite end of the
cell, which cleaves into two daughter gametes, so
called secondary spermatocytes or oocytes
24. MEOSIS II
• Similar to ordinary mitotic division. Each
chromosomes, which exist as a pair of
chromatids, becomes aligned along the
equatorial plane and then slits longitudinally,
leading to formation of two new daughter
gametes known as spermatids or ova.
25.
26. DNA
Human body consists
6000 billion cells
constituting various
tissue & organ systems .
DNA is considered as
chemical blue print of life
.
27. DNA –Deoxy ribo nucleic acid
DNA consists of :
Deoxyribose sugar(5C)
A phosphate group
Nitrogen bases - that are further divided into
purines –adenine ,guanine
pyrimidines –thymine, cytosine and
uracil (present in RNA in place of thymine)
28. It is a double helix which consists of
phosphate-sugar back bone .
Back bone is formed by phosphodiester bonds
between the 3’ and 5’ carbons of adjacent
sugars .
Bridging the gap between the two chains are
of paired nucleotide bases .
The chains are anti parallel to each other.
Adenine and thymine are connected by double
hydrogen bond .
Guanine and cytosine are connected by triple
hydrogen bond .
29.
30. The process of copying of DNA in which two
chains of DNA separated, and each chain builds
up its complement, giving rise to two identical
daughter DNA.
Replication
31. The two strand of the DNA double helix
seperate through the action of enzyme DNA
helicase, each DNA strand through specific
base pairing, resulting in two daughter DNA
duplexes that are identical to the original
molecule.
In this way, when cell divide, the genetic
information is conserved and transmitted
unchanged to each daughter cell.
32. Genetic code (triplet code)
• Genetic information is stored in the DNA
molecule in the form of triplet code which
refers to series of three bases in DNA or RNA
which codes for specific amino acids.
Codon –Triplet of nucleotide bases in m-
RNA which codes for a particular amino acid.
Anticodon – Complimentary triplet of t-RNA
molecule which binds to m-RNA codon .
33. DNA is formed in the nucleus but proteins are
formed in cytoplasm ,this involves two
processes :
1. Transcription
2. Translation
34. Transcription
The process whereby genetic information is
transmitted from DNA to RNA is called
transcription.
The information stored in the genetic code is
transmitted from DNA of a gene to messenger
RNA or mRNA .
mRNA is a single stranded, being synthesized by
enzyme RNA polymerase that adds the
appropriate complementary ribonucleotide to 3’
end of the RNA chain.
35. •Complementary bases are found in the
RNA.
•Cytosine with guanine,
•thymine with adenine, and
•adenine with uracil
36. Translation
• Translation is the transmission of the genetic
information from mRNA to protein.
• The mRNA is then associated with ribosome,
which are actually the sites for protein synthesis.
• The mRNA forms a template for the sythesis of
the protein.
37. In the cytoplasm, there is another form of RNA is
present called transfer-RNA .
Amino acid is activated by reacting ATP for
incoporation into polypeptide chain.
Activated amino acid attach itself to one end of
a particlular t-RNA.
38. The other end of transfer RNA combine with
the m-RNA. Thus a particular triplet on the
mRNA is related through transfer RNA to a
amino acid the ribosomes moves along the
messenger-RNA in a zipper –like fashion ,the
amino acids linking up to form polypeptide
chain.
39.
40. Human chromosome
These are thread like structures located in the
cell nucleus .
Each species has a specific number of
chromosomes
Humans have 23 pairs .
22 pairs are autosomes ,1 pair is sex
chromosomes XX/XY
Chromosomes vary in shape depending on the
position of centromere.
41. Structure of Chromosomes
Each DNA duplex is coiled around itself –
primary coiling.
This is coupled around histone ‘beads’ called
nucleosomes – secondary coiling
Nucleosomes are coiled to form chromatin
fibres, around a protein matrix or scaffold –
tertiary coiling
42. Chromatin fibres are coiled to form loops –
quaternary coiling
The loops are further wound in a tight helix to
form the chromosome – that can be seen under
a microscope.
43.
44. • Individual chromosomes differ not only in
position of centromere but also in their overall
length(amount of DNA ).
• Human chromosomes are divided into 8
groups depending on size ,position of
centromere, presence or absence of satellites .
• If the allele are identical it is called
homozygous ,if the alleles differ it is called
heterozygous.
46. Centromere
Middle
Off center
If close to the end
Name
Metacentric
Sub metacentric
Acrocentric(in this
the short knob like
on the short arm is
called satellite
Morphologically chromosomes divided into three
type according to the position centomere
47.
48. •A gene is a unit of information and
corresponds to a discrete segment of DNA
with a base sequence that encodes the amino
acid sequence of a polypeptide.
•It vary greatly in size from less than 100 base
pairs to several million base pairs. In humans
there are an estimated 50-100000 genes
arranged on 23 chromosomes.
GENE
49. Genes of particular interest in craniofacial
developmemt are:
Hox group
Msx 1 and Msx 2(muscle segment)
Dlx (distalless)
Otx (orthodontical)
Gsc (goosecoid)
Shh (sonic hedgehog)
50. HOMEOBOX GENES (HOX)
•The homeobox genes were originally
described as a conserved helix-turn-helix DNA
of about 180 base pair sequence, which is
believed to be characteristic of genes involved
in spatial pattern control and development.
•This encode a 60 amino acid domain which
bind to DNA.
51. •Proteins from homeobox containing are
known as HOX genes, are therefore important
transcription factors which specify cell fate
and establish a regional anterior/posterior axis.
•The first genes found to encode
homeodomain proteins were Drosophila
developmental control genes, in particular
homeotic genes, from which the name
homeobox was derived.
52. •Four homeobox gene clusters (HOXA,
HOXB, HOXC, and HOXD) that comprise a
total of 39genes have been identified in
humans. Each cluster contains a series of
closely linked genes.
• In each HOX cluster there is a direct linear
correlation between the position of the gene
and its temporal and spatial expression. These
observations indicate that these genes play a
crucial role in early morphogenesis.
53.
54. •Msx -1 development of secondary palate and
tooth.
familial tooth agenesis – missing 2nd
premolar
and 3rd
molar.
•Msx- 2 Craniosynostosis i.e premature fusion
of cranial suture.
•SHH(sonic hedgehog) holoprosencephaly
i.e.,incomplete cleavage of the developing
brain into separate hemisphere and ventricles.
55. Mutations
Mutation is defined as an heritable
alteration or change in genetic material .
Mutation drive evolution but can be
pathogenic. mutation can be arise through
exposure to mutagenic agents like
radiation,chemicals etc., but vast majority
occur spontaneously through the error in
DNA replication and repair.
56. Mutations can be coded or noncoded ,Coded are
the once that are transmitted .
Somatic mutations may cause adult -onset
disease such as cancer but cannot be trasmitted to
offspring . A mutation in gonadal tissue or gamete
can be transmitted to future generation unless it
affects fertility or survival into adulthood.
57. Mutations can be further divided into
SUBSTITUTION
A substitution is the replacement of a single
nucleotide by another.These are the most
common type of mutation. Single nucleotide
base is replaced by a different nucleotide base
transition–purine to purine/pyrimidine to
pyrimidine. transversion – purine to
pyrimidine or vice versa.
58. • Deletion
Deletion is the loss of 1 or more nucleotides.
Larger deletion may result in partial or whole
gene deletion and may arise through unequal
crossover between repeat sequences.
Insertion
Insertion is the addition of 1 or more
nucleotides into gene. If insertion occurs in a
coding sequence and involve one,two or more
nucleotides that are not a multiple of three ,it
will distrupt the reading frame.
59. Mutation can also be subdivided into main
groups according to the effect on polypeptide
sequence of encoded protein.
Synonyms –Mutations does not alter the
polypeptide product of gene also called
synonyms/ silent mutation
STRUCTURAL EFFECTS OF MUTATION ON
PROTEIN
60. • Non synonymous –Mutations lead to
alterations in the encoded polypeptide .This
mutation occur
in one of three ways:
Missense –A simple base pair substitution can
result in coding for a different aminoacid and
synthesis of altered protein.
• Nonsense –A substitution that leads to the
generation of one of the stop codon will result
in premature termination of translation of
polypeptide chain.
61. Frameshift- If mutation involves insertion or
deletion of nucleotides that are not multiple of
three, it will disrupt the reading frame and
constitute what known as a framshift mutation
.
The majority of mutations are likely to
cause reduced fitness ,a reduced ability of the
resulting zygote to contribute progeny to next
generation , in this way harmful genes tend be
eliminated from the population .
62. Chromosomal abnormalities
Alterations of the genetic material which
involves many genes and large amount of
DNA . These can be divided into:
1. Numerical abnormalities
2. Structural abnormalities
63. Numerical abnormality
Numerical abnormality involve the loss or gain
of one or more chromosomes, which referred
to as aneuploidy or the addition of one or
more complete haploid complements, which is
known as polyploidy.
Loss of a single chromosomes results in
monosomy. Gain of one or two homologous
chromosomes is referred to as trisomy and
tetrasomy, respectively.
64. Structural abnormality
Structural chromosomes rearrangement result
from chromosomes breakage with subsequent
reunion in a different configuration.They can be
divided into:
Translocations –transfer of genetic material
from one chromosome to another(non
homologous).
Inversions –rearrangement within the same
chromosome, segment is rotated 180 degrees.
65. Insertion –one segment is removed from
normal position and inserted in different
position .
Deletion –a missing chromosomal segment.
66. Syndrome due to chromosomal
abnormalities
Down syndrome
It results from trisomy 21.
C/F : Brachycephaly
Mental retardation
Maxillary hypoplasia
Flat nasal bridge
Delayed eruption
Growth retardation
Moon face
macroglossia
67. Patau’s syndrome
It results from trisomy 13
C/F: Mental retardation
Microcephaly
Cleft lip/palate
Micrognathia, small eyes.
68. Edward’s syndrome
It results from trisomy 18.
C/F: Mental retardation
Brachycephaly
Micrognathia
Hypodontia
CLP
Prominent occiput
Tightly clenched hands.
69. Turners syndrome
It results from XO
C/F: Retarded growth
Micrognathia
Ovarian agenesis.
Klinefelter’s syndrome
It results from XXY
C/F: Gynecomastia
Small testes
Decreased facial hair.
71. Cri –du-chat
syndrome
It results from deletion of
5p chromosomes
C/F: Mental retardation
Microcephaly
Characterstic cry(cat like
cry)
72. All chromosomes exist in pairs so our cells
contain two copies of each gene, which may be
alike or may differ in their substructure and
their product.
Different forms of genes at the same locus or
position on the chromosome are called alleles.
If both copies of the gene are identical, the
individual is described as homozygous, while if
they differ, the term used is heterozygous.
Modes of Inheritance
74. Mendelian inheritance / single gene
inheritance
Over 11000 traits in human exhibit
mendelian inheritance e.g. blood
group,hemophilia.
A trait or disorder that is determined by a
genes on an autosomes is said to show
Autosomal inheritance whereas a trait or
disorder determined by gene on one of the
sex chromosomes is said to show sex-
linked inheritance
75. Autosomal inheritance and sex linked
inheritance both can be dominant or
recessive.
In autosomal dominant inheritance both the
sexes are equally affected and presence of
only one dominant allele manifests the trait.
In autosomal recessive traits both the
alleles (homozygous) should be present.
76. X Linked Dominant inheritance – both
males and females are affected but females
are more frequently affected.
Affected male transmit the trait to his
daughters but not the son. Expression is
less severe in female heterozygotes than
affected males.
77. X Linked Recessive inheritance – this trait
affects males (because of only 1X chromosome)
females are usually carriers.
Y Linked Inheritance / Holandric inheritance – Y
chromosomes contains only few genes.
About 20–25 Y linked genes have been
identified e.g. hairy ears, webbed toes.
78. Non Mendelian inheritance
A number of disorders are known which do
not follow patterns of Mendelian
inheritance several mechanisms account for
this :
Anticipation
Mosaicism
Uniparental disomy
Genomic imprinting
Mitochondrial inheritance
79. Anticipation: the disease occurs with increasing
severity in subsequent generation.
Mosaicism: occasionally a chromosome change
occurs after the zygote has been formed which
may lead to sections of tissues growing side by
side bearing different chromosomal constitution
such individuals are known as Mosaics.
Uniparental disomy: individuals who inherit
both homologous chromosomes only from one
parent.
80. Genomic imprinting: Although it was
originally believed that genes on
homologous chromosomes were expressed
fully, it is now recognized that different
clinical features can result depending on
whether a gene is inherited from father or
mother.
Mitochondrial inheritance: mitochondria
and its DNA are almost exclusively
inherited from mother through oocyte e.g.
diabetes with deafness.
81. Many traits having strong genetic component
are
Height
Intelligence
Birth weight
Diabetes mellitus
Schizophrenia
Hypertension
Cleft lip & palate
82. Polygenic inheritance
Many of these traits do not follow the simple
mendelian genetics, but determine by interaction
of number of gene at different loci,each with
small but additive effect, together with
environmental factor.
Determination of heritability for polygenic
characters is difficult e.g. mandibular
micrognathia can occur in chromosomal
disorders such as turner’s syndrome,in
monogenic disorders such as treacher collins
syndrome or non syndromic polygenic factors.
84. Discontinuous polygenic traits
When present these traits can vary continuously
There is an underlying scale of continuous
variation of liability to develop the condition
resulting from a combination of all the genetic &
environmental influences involved
The condition occurs only when the liability
exceeds a critical threshold value & the greater
the value beyond the threshold the more severe
the disease
85. Cleft lip & palate is a congenital malformation
inherited this way .
The parents of the affected are often unaffected and
there may be no family history .
Giving birth to an affected child shows that parents
have some underactive genes for lip & palate
formation .
Some multifactorial traits show unequal sex ratio ,
like more common in males. The incidence is
increased in relatives of affected males & is even
more increased in relatives of affected females.
86. Continuous polygenic traits
Many normal human characteristics are
determined as continuous multifactorial traits.
These traits by definition have a continuously
graded distribution.
For height there is a range from the very tall to the
markedly short.
Similarly malocclusion is considered as a
variation of occlusion in a continuous multi-
factorial trait.
87. Etiologic heterogeneity
Both continuous & discontinuous variation have a
multifactorial basis so that different patients are not
necessarily affected for same reason .
Cleft palate patients no single cause can be identified ,it
can be due to chromosomal disorder –Wolf Hirschhorn
syndrome, trisomy 13 (patau syndrome),in monogenic
disorders such as Vander Woude syndrome ,it may also
be associated with cigarette smoke ,alcohol , drugs .
88. There is evidence for genotype environment
interaction in orofacial clefting, with certain major
genes conferring susceptibility to particular
teratogenic agents.
89. Twin studies
Twinning –when birth is given to 2 infants at
the same time they are called twins .
Twins can be identical i.e .,monozygotic (MZ)
or non-identical i.e., dizygotic (DZ) –
depending on whether they originate from a
single conception or from two separate
conceptions.
91. Monozygotic /identical twins
They arise from a single fertilized ovum.
• Identical genetic makeup.
• Same sex.
• Resemble each other .
• Monozygotic twins have identical genotype ,any
phenotypic difference due to different environment
can be possible.
92. Dizygotic /fraternal twins
They develop from two different embryos .
Genetically alike like any other siblings .
Can be of different sex.
Resemblance only like siblings .
Difference in Dizygotic twins are of both genetic
and environmental is seen.
93. Basic methodology
Providing the zygosity of twins whether they are
monozygotic or dizygotic .
Studying the effect of heredity on craniofacial
development among monozygotic and dizygotic twins
and comparing development among the two types and
comparing them to find out the differences .
94. Various methods have been used to differentiate
Hair and eye color
Ear form
Dermatoglyphics
Teeth morphology
Phenylthiocarbamide taste sensitivity
Blood groups
Serum proteins (gamma globulins)
95. Influence of genetics in
malocclusion
Malocclusion may be defined as a significant
deviation from what is defined as normal or ideal
occlusion .
Many components are involved in normal occlusion.
The most important are
• The size of the maxilla
• The size of the mandible
96. • The factors, which determine the relationship
between the two skeletal bases such as cranial
base .
• Arch form.
• Size and morphology of teeth present .
• Soft tissue morphology .
97. Extensive cephalometric studies have been
carried out to determine the heritability of certain
craniofacial parameters in class II division I
malocclusion .
These investigation have shown that in the class II
patients, the mandible is significantly more
retruded than in class I patients, with the body of
the mandible length smaller and overall
mandibular length reduced.
Class II Division I Malocclusion
98. These studies also showed a higher correlation
between the patient and his immediate family
that data from random pairings of unrelated
siblings, thus supporting the concept of
polygenic inheritance for class II division I
malocclusion.
99. Markovic 1992 carried out a clinical and
cephalometric study of 114 Class II division-2
malocclusions, 48 twin pairs and six sets of triplets.
Intra- and Inter- pair comparisons were made to
determine concordance/ discordance rate for
monozygotic and dizygotic twins.
Class II Division 2 malocclusion
100. Of the monozygotic twin pairs, 100% demonstrated
concordance for the Class II division-2
malocclusion, whereas almost 90% of the dizygotic
twin pairs were discordant.
This is strong evidence for genetics as the main
etiological factor in the development of class II
division2 malocclusion.
101. Suzuki (1961) studied 1362 persons from 243
Japanese families and noted that, while the index
cases had mandibular prognathism,there was a
significantly higher incidence of this trait in other
members of his family (34.4%) in comparison of
families of individuals with normal occlusion (7.5%).
Schulze and weise (1965) also studied mandibular
prognathism in monozygotic twins and dizygotic
twins. They reported that concordance in
monozygotic twins was six times higher than
amongs dizygotic twins.
CLASS III MALOCCLUSION
102. According to this, mammalian dentition can be
divided into several developmental fields.
The developmental fields include the molar/
premolar field, canine and the incisor fields.
Among the fields, dental variability manifests
itself strongly in the distal than in the mesial
direction.
Ex:- lateral incisor is more prone to variation
than the central incisor.
Butler field theory
103. Genetic influence on tooth
number, size,morphology,
position, & eruption
Msx 1 & Msx 2 are responsible for stability in dental
patterning.
Clinical evidence suggests congenital absence of teeth &
reduction in tooth size are associated.
A study of children with missing teeth found up to half
of their siblings or parents also had missing teeth .
104. Various developmental dental disorders, which are
under the influence of genes, include-
Supernumerary teeth
Abnormal tooth shape
Submerged primary molars
Ectopic eruption and
Transposition of canines
105. Supernumerary teeth
Brook (1974) reported that prevalence of
supernumerary teeth in British school children was
2.1% in permanent dentition with male:female ratio
of 2:1.
In Hong Kong the prevalence was around 3 % with
male:female ratio 6.5:1 . Most common
supernumerary tooth is the mesiodens .These are
commonly present in siblings and parents of the
patients ,it does not follow simple mendalian pattern .
106. Abnormal tooth shape
Alvesalo &Portin (1969) provided substantial
evidence supporting the view that missing
,malformed lateral incisors may be the result of
common gene defect .
All of these defects show familial trends ,female,
preponderance and association with other dental
anomalies ,such as other missing teeth ,ectopic
canines ,suggesting a polygenic etiology.
107. Ectopic maxillary canines
Peck et al (1994) concluded that palatally ectopic
canines were an inherited trait ,being one of the
anomalies in a complex of genetically related dental
disturbances –supernumerary teeth ,missing teeth
,transposition ,tooth size reduction,other ectopically
positioned teeth.
Peck etal( 1997) classified a number of diferent types of
tooth transposition in both maxillary and mandibular
arches,with maxillary canine/first premolar class
position being the most common.
108. Submerged primary molars
It occurs most commonly in mandibular arch ,the
siblings of affected children likely to affect in
about 18percent and there is a high rate of
concordance in monozygotic twins .
A number of studies provide evidence for
genetically determined primary failure of
eruption .
110. From a biological point of view gene map
(DNA sequence) is :
The basic principle of order (molecular
anatomy)
A reflection of past (molecular archaeology)
A functional substrate (molecular physiology)
111. Human genome project
Begun formally in 1990, the U.S. Human Genome
Project is a 13-year effort coordinated by the U.S.
Department of Energy and the National Institutes
of Health. The project originally was planned to
last 15 years, but rapid technological advances
have accelerated the expected completion date to
2003.
112. Determine the sequences of the 3 billion
chemical base pairs that make up human
DNA.
Identify all the approximate 30,000 genes
in human DNA.
Store this information in databases.
Improve tools for data analysis.
Transfer related technologies to the private
sector .
Address the ethical, legal, and social issues
(ELSI) that may arise from the project.
Project goals was to
113. The Oral &Craniofacial genome project seeks to
set up collaborative laboratory research projects
on human & mouse embryonic tissue .
The objective is to build up DNA libraries with a
view to discover the genes for normal &
abnormal oral & craniofacial development .
114. conclusion
The development of skeletal structures is partly
under environmental control and partly under
genetic control. Therefore, the importance of
genetic basis of malocclusions cannot be denied .
Up to date, there has been an immense progress in
the field of genetically supported orthodontics.
115. In the beginning of the 21st century as the human
genome project is completed, the possibility to
discriminate the causes of a malocclusion will no
longer be a dream as the identification of the
underlying factors starts with the localization of its
defective gene in the human genome .
116. Although, it is very challenging to reveal the
genetic component of most malocclusions and
dental anomalies because of the polygenic nature
of craniofacial traits, data provided by the human
genome project have made it feasible to map
inherited conditions related to the dentofacial
development.
117. However, further genetic studies are required to
clearly determine all the specific genes leading to a
particular skeletal variability. The rapid
development in this field could lead to the genetic
correction of the genetically controlled dentofacial
anomalies and malocclusions, perhaps in near
future.