- The document summarizes DNA sequencing techniques and DNA cloning methods that are used in genetic engineering and biological research.
- It describes how DNA sequencing relies on the principle of complementary base pairing and how the first automated sequencing technique was chain termination sequencing developed by Sanger.
- It explains how DNA cloning involves inserting foreign DNA into plasmids, which are then inserted into bacterial cells to produce multiple copies of the gene of interest for research purposes. Restriction enzymes and ligases are used to combine DNA fragments.
Ch 16: The Molecular Basis of Inheritance veneethmathew
DNA is the genetic material that is faithfully replicated and passed from parents to offspring. James Watson and Francis Crick discovered the double helix structure of DNA in 1953, which explained how DNA could store and replicate the instructions for making organisms. Their model showed that DNA consists of two strands coiled around each other, with nucleotides on the strands bonded together through base pairing with adenine bonding only to thymine and guanine only to cytosine. This allows each strand to serve as a template for duplicating the other, explaining DNA's role in inheritance and allowing organisms to pass genetic information between generations.
This document provides an overview of the discovery of DNA as the genetic material. It discusses early evidence from experiments transforming bacteria and showing that viral DNA enters bacterial cells. It also describes Rosalind Franklin's X-ray crystallography work that provided insights into DNA's structure and allowed Watson and Crick to deduce the double helix model with paired nitrogenous bases. Their model resolved the structure and showed how DNA could store and replicate the genetic information required for inheritance.
This document summarizes regulation of gene expression in bacteria and eukaryotes. It discusses how bacteria regulate genes through the operon model, including repressible and inducible operons like the trp and lac operons. In eukaryotes, it describes various levels of gene expression regulation, from chromatin structure and histone/DNA modifications, to transcription factors and epigenetic inheritance. Gene expression can be regulated at the stages of transcription, RNA processing, transport, translation and degradation.
This document provides an overview of the process by which DNA directs protein synthesis through transcription and translation. It discusses the flow of genetic information from DNA to mRNA to protein. Key points include: transcription produces messenger RNA from DNA templates in the nucleus; eukaryotic pre-mRNA is processed before translation; translation occurs in the cytoplasm using tRNA to add amino acids to growing polypeptide chains on ribosomes according to mRNA codons. The genetic code is nearly universal and specifies 20 amino acids using triplets of nucleotides.
This document provides an overview of Chapter 14 from Campbell Biology, 9th Edition which discusses Gregor Mendel and his experiments that established the basic principles of heredity and inheritance through genetics. It summarizes Mendel's experiments with pea plants, the traits he studied, his development of the laws of segregation and independent assortment. It also discusses terminology used in genetics like genes, alleles, phenotypes, genotypes, dominance, and how Mendel's principles can explain more complex inheritance patterns.
This document summarizes key concepts from a lecture on gene expression from DNA to protein. It discusses:
1) How genes specify proteins via transcription of DNA into mRNA and translation of mRNA into proteins. RNA acts as the bridge between genes and proteins.
2) Experiments by Beadle and Tatum showing that mutations in neurospora resulted in inability to synthesize specific enzymes, supporting the "one gene-one enzyme" hypothesis.
3) The genetic code is cracked - codons of 3 nucleotide bases in mRNA specify 20 different amino acids or stop signals in proteins. The code is nearly universal across life.
The document provides an overview of cell communication and signaling. It discusses:
- Cells communicate via chemical signals such as epinephrine.
- Signal transduction pathways convert signals at the cell surface into responses.
- Reception involves signal molecules binding receptors, transduction uses cascades of molecular interactions to relay signals from receptors to target molecules, and response leads to activation of cellular responses.
- Common mechanisms of signaling include G-protein coupled receptors, receptor tyrosine kinases, calcium ions, cyclic AMP, and inositol triphosphate.
This document provides an overview of meiosis and sexual life cycles by discussing:
- The transmission of traits from parents to offspring through inheritance of genes and chromosomes.
- The differences between asexual and sexual reproduction, and how meiosis and fertilization alternate in sexual life cycles.
- The three main types of sexual life cycles seen in animals, plants/algae, and fungi/protists with regards to timing of meiosis, fertilization, and diploid/haploid stages.
- Key cellular processes like meiosis, fertilization, mitosis and their roles in maintaining chromosome number and producing genetic variation in offspring.
Ch 16: The Molecular Basis of Inheritance veneethmathew
DNA is the genetic material that is faithfully replicated and passed from parents to offspring. James Watson and Francis Crick discovered the double helix structure of DNA in 1953, which explained how DNA could store and replicate the instructions for making organisms. Their model showed that DNA consists of two strands coiled around each other, with nucleotides on the strands bonded together through base pairing with adenine bonding only to thymine and guanine only to cytosine. This allows each strand to serve as a template for duplicating the other, explaining DNA's role in inheritance and allowing organisms to pass genetic information between generations.
This document provides an overview of the discovery of DNA as the genetic material. It discusses early evidence from experiments transforming bacteria and showing that viral DNA enters bacterial cells. It also describes Rosalind Franklin's X-ray crystallography work that provided insights into DNA's structure and allowed Watson and Crick to deduce the double helix model with paired nitrogenous bases. Their model resolved the structure and showed how DNA could store and replicate the genetic information required for inheritance.
This document summarizes regulation of gene expression in bacteria and eukaryotes. It discusses how bacteria regulate genes through the operon model, including repressible and inducible operons like the trp and lac operons. In eukaryotes, it describes various levels of gene expression regulation, from chromatin structure and histone/DNA modifications, to transcription factors and epigenetic inheritance. Gene expression can be regulated at the stages of transcription, RNA processing, transport, translation and degradation.
This document provides an overview of the process by which DNA directs protein synthesis through transcription and translation. It discusses the flow of genetic information from DNA to mRNA to protein. Key points include: transcription produces messenger RNA from DNA templates in the nucleus; eukaryotic pre-mRNA is processed before translation; translation occurs in the cytoplasm using tRNA to add amino acids to growing polypeptide chains on ribosomes according to mRNA codons. The genetic code is nearly universal and specifies 20 amino acids using triplets of nucleotides.
This document provides an overview of Chapter 14 from Campbell Biology, 9th Edition which discusses Gregor Mendel and his experiments that established the basic principles of heredity and inheritance through genetics. It summarizes Mendel's experiments with pea plants, the traits he studied, his development of the laws of segregation and independent assortment. It also discusses terminology used in genetics like genes, alleles, phenotypes, genotypes, dominance, and how Mendel's principles can explain more complex inheritance patterns.
This document summarizes key concepts from a lecture on gene expression from DNA to protein. It discusses:
1) How genes specify proteins via transcription of DNA into mRNA and translation of mRNA into proteins. RNA acts as the bridge between genes and proteins.
2) Experiments by Beadle and Tatum showing that mutations in neurospora resulted in inability to synthesize specific enzymes, supporting the "one gene-one enzyme" hypothesis.
3) The genetic code is cracked - codons of 3 nucleotide bases in mRNA specify 20 different amino acids or stop signals in proteins. The code is nearly universal across life.
The document provides an overview of cell communication and signaling. It discusses:
- Cells communicate via chemical signals such as epinephrine.
- Signal transduction pathways convert signals at the cell surface into responses.
- Reception involves signal molecules binding receptors, transduction uses cascades of molecular interactions to relay signals from receptors to target molecules, and response leads to activation of cellular responses.
- Common mechanisms of signaling include G-protein coupled receptors, receptor tyrosine kinases, calcium ions, cyclic AMP, and inositol triphosphate.
This document provides an overview of meiosis and sexual life cycles by discussing:
- The transmission of traits from parents to offspring through inheritance of genes and chromosomes.
- The differences between asexual and sexual reproduction, and how meiosis and fertilization alternate in sexual life cycles.
- The three main types of sexual life cycles seen in animals, plants/algae, and fungi/protists with regards to timing of meiosis, fertilization, and diploid/haploid stages.
- Key cellular processes like meiosis, fertilization, mitosis and their roles in maintaining chromosome number and producing genetic variation in offspring.
Ch 15: The Chromosomal Basis of Inheritanceveneethmathew
1) The document summarizes a lecture on the chromosomal basis of inheritance, beginning with an overview of how genes are located on chromosomes.
2) It then discusses Mendelian inheritance having a physical basis in chromosome behavior during meiosis and fertilization. Thomas Morgan's experiments with fruit flies provided evidence linking genes to chromosomes.
3) The lecture also covers sex-linked inheritance patterns and how linked genes on the same chromosome tend to be inherited together.
1. The document discusses meiosis and sexual life cycles in biology. It provides details on the stages of meiosis, including prophase I, metaphase I, anaphase I and telophase I.
2. Meiosis results in four haploid daughter cells rather than two, and reduces the number of chromosome sets from diploid to haploid. It occurs in two divisions: meiosis I and meiosis II.
3. There are three main types of sexual life cycles that differ in the timing of meiosis and fertilization - in animals, plants and fungi. This ensures genetic variation between generations.
Viruses are small infectious particles that can only replicate inside host cells. They contain either DNA or RNA surrounded by a protein coat called a capsid, and some have an outer envelope. Viruses infect a limited range of host cells and use the cell's machinery to produce new virus particles, which are then released to infect other cells. Viruses that infect bacteria can undergo a lytic cycle that destroys the host cell or a lysogenic cycle where the viral DNA is incorporated into the host chromosome as a prophage. Retroviruses like HIV contain RNA and use reverse transcriptase to insert viral DNA into the host genome as a permanent provirus. While viruses cause many diseases, vaccines can help stimulate immunity to prevent infection
Ch 9: Cell Respiration and Fermentationveneethmathew
- Cellular respiration consists of three main stages: glycolysis, the citric acid cycle, and oxidative phosphorylation.
- Glycolysis breaks down glucose into pyruvate, generating a small amount of ATP through substrate-level phosphorylation.
- The citric acid cycle further oxidizes pyruvate and other molecules, generating more ATP and electron carriers.
- Oxidative phosphorylation generates the majority of ATP through an electron transport chain that harnesses the energy of electron transfers to power ATP synthesis.
1) Gregor Mendel conducted experiments with pea plants to study inheritance of traits from parents to offspring. Through his experiments, he discovered that traits are inherited in discrete units, which he called "factors" and which we now call genes.
2) Mendel's experiments led him to formulate two laws of inheritance: the Law of Segregation, which states that organisms inherit two copies of each gene, one from each parent, and these genes segregate or separate during the formation of gametes; and the Law of Independent Assortment, which states that different genes assort independently of one another during gamete formation.
3) Mendel's laws reflect the rules of probability - the alleles of one
Photosynthesis is the process by which plants, algae, and some bacteria use sunlight, water and carbon dioxide to produce oxygen and energy in the form of glucose. It occurs in chloroplasts and involves two stages - the light-dependent reactions where ATP and NADPH are produced, and the light-independent Calvin cycle where glucose is formed. Chlorophyll and other pigments absorb sunlight which is used to power the transfer of electrons and production of chemical energy carriers. Photosynthesis ultimately feeds the biosphere by producing organic molecules and oxygen from inorganic sources.
This document provides an overview of cellular metabolism and energy transformation. It discusses key topics including:
1) Metabolism transforms matter and energy in living cells through ordered chemical reactions. Metabolic pathways involve series of enzyme-catalyzed steps that either release (catabolism) or consume (anabolism) energy.
2) ATP is the main energy currency molecule in cells. It is regenerated through catabolic pathways and powers cellular work through exergonic hydrolysis reactions that drive endergonic processes.
3) Enzymes are protein catalysts that lower the activation energy of metabolic reactions, speeding up biochemical transformations without being consumed in the process. They confer specificity to reactions by precisely
This document provides an overview and key concepts from a lecture on the evolution of populations from Campbell Biology, 9th Edition. It discusses how natural selection acts on genetic variation within populations to drive microevolution over generations. The three main mechanisms that can alter allele frequencies in a population and lead to evolutionary change are natural selection, genetic drift, and gene flow. Natural selection is the only mechanism that consistently results in adaptive evolution. The lecture also examines examples of natural selection in Darwin's finches and provides explanations of genetic drift, the founder effect, and the bottleneck effect.
15 the chromosomal basis of inheritancekindarspirit
This document summarizes a chapter from a biology textbook about the chromosomal basis of inheritance. It discusses how Mendel's theories of heredity were later linked to chromosomes through the experiments of Thomas Hunt Morgan using fruit flies. Morgan found that a white eye color mutant in male flies was located on the X chromosome, supporting the idea that genes have specific locations on chromosomes and explaining the patterns of inheritance. The chapter outlines Mendel's laws of segregation and independent assortment and how chromosome behavior during meiosis can account for these laws.
1. The document discusses genetic engineering and biotechnology, including techniques like recombinant DNA, gene cloning, PCR, and cloning organisms.
2. Key terms defined include genetic engineering, biotechnology, recombinant DNA, gene cloning, restriction enzymes, and plasmids.
3. Recombinant DNA is made by cutting DNA with restriction enzymes and ligating pieces into plasmids, which are then inserted into bacteria.
The document discusses the chromosomal basis of inheritance. It explains that genes are located on chromosomes and Mendel's hereditary factors were genes. It describes how Morgan's experiments with fruit flies provided evidence that supported the chromosome theory of inheritance. His findings showed that genes have specific loci on chromosomes and that chromosomes segregate and assort independently during meiosis, accounting for Mendel's laws. The document also discusses sex linkage, with genes on the X chromosome being X-linked and exhibiting unique inheritance patterns. It describes how linked genes on the same chromosome tend to be inherited together but can sometimes be separated through genetic recombination via crossing over during meiosis.
This document provides an overview of a lecture on bacteria and archaea. It discusses their structural and functional adaptations that allow prokaryotes to thrive in diverse environments. Key points include:
- Prokaryotes have a variety of shapes and sizes, and cell surfaces like cell walls, capsules, and fimbriae that aid environmental interactions.
- They reproduce rapidly through binary fission and genetic diversity arises from high mutation rates and horizontal gene transfer between cells through transformation, transduction, and conjugation.
- Adaptations like motility, endospores, metabolic pathways, and rapid evolution allow prokaryotes to be highly successful and found almost everywhere on Earth.
1) The document summarizes key concepts from Chapter 24 of Campbell Biology about the origin of species. It discusses allopatric and sympatric speciation, describing how new species can form with or without geographic separation between populations.
2) Reproductive isolation is formed by prezygotic barriers that prevent mating or fertilization, and postzygotic barriers that result in non-viable or infertile hybrid offspring.
3) Examples are given of allopatric speciation including mosquitofish that evolved in isolated ponds, and snapping shrimp separated when the Isthmus of Panama formed.
The document discusses the cell cycle and cell division. It makes the following key points:
1) The cell cycle consists of interphase and the mitotic (M) phase. Interphase includes cell growth and DNA replication, while mitosis involves the equal division of genetic material into two daughter cells.
2) In eukaryotes, cell division results in two genetically identical daughter cells through mitosis and cytokinesis. Mitosis ensures each cell receives one copy of each chromosome, while cytokinesis physically separates the cytoplasmic components.
3) The stages of mitosis are prophase, prometaphase, metaphase, anaphase and telophase. During this process, chromosomes condense and
1. The document describes a lecture on phylogeny and the tree of life from Campbell Biology. It discusses how systematists use morphological and molecular data to infer evolutionary relationships and construct phylogenetic trees showing these relationships.
2. Key points include how homologies are used to determine shared ancestry, while analogies indicate convergent evolution. Maximum parsimony and maximum likelihood methods are used to evaluate potential phylogenetic trees.
3. Shared derived characters that appear for the first time in a particular clade provide evidence for which groups of species share a more recent common ancestor on the tree of life.
Gene cloning involves inserting DNA fragments from one source into plasmids or bacteria. This allows for the production of multiple copies of the gene. Restriction enzymes and DNA ligase are used to cut and paste DNA fragments into plasmids. The plasmids are then inserted into bacteria which replicate, producing many copies of the gene. Libraries of cloned DNA fragments can be stored in bacteria or plasmids. The library can be screened to identify clones containing genes of interest using probes complementary to the target gene. Expressed genes can be studied by producing their protein products in bacterial or eukaryotic cells.
04 carbon and the molecular diversity of lifekindarspirit
This document provides an overview of chapter 4 from Campbell Biology, 9th edition which discusses carbon and the molecular diversity of life. It covers how carbon is the backbone of living organisms and can form large, complex molecules like proteins, DNA, carbohydrates. It also summarizes key points about organic chemistry, the formation of carbon-carbon bonds, isomers, important functional groups in biological molecules, and how ATP is used to store energy. The document contains lecture slides with titles, images, and bullet points about these topics.
- Gregor Mendel conducted experiments breeding pea plants to study inheritance of traits from parents to offspring. He found that traits were inherited in discrete units, which we now know as genes.
- In his experiments, Mendel identified two laws of inheritance. The Law of Segregation states that genes separate during gamete formation so offspring receive only one allele for each gene from each parent. The Law of Independent Assortment states that different genes assort independently during gamete formation.
- Mendel's discoveries demonstrated that inheritance has a particulate, rather than blending, nature. His work established the foundations of classical genetics and heralded the particulate theory of inheritance.
1) Cellular respiration involves the breakdown of glucose and other organic molecules to extract energy through redox reactions in the form of ATP.
2) Glycolysis breaks down glucose into two pyruvate molecules in the cytoplasm, generating a small amount of ATP through substrate-level phosphorylation.
3) Pyruvate is further oxidized in the mitochondrion, entering the citric acid cycle which completes the oxidation of pyruvate and generates more ATP and electron carriers like NADH and FADH2.
4) Most ATP is produced through oxidative phosphorylation, as electrons from NADH and FADH2 are passed through an electron transport chain which powers ATP synthesis.
This document provides an overview of Mendelian genetics and patterns of inheritance. It discusses key topics such as:
1) Mendel's experiments with pea plants in the 1860s which discovered the fundamental principles of genetics and heredity.
2) Mendel's laws of segregation and independent assortment which explain inheritance patterns for single traits and two traits, respectively.
3) How chromosome behavior during meiosis accounts for Mendel's laws, with homologous chromosomes separating during meiosis I relating to the law of segregation, and independent assortment of chromosomes during metaphase I relating to the law of independent assortment.
This document summarizes DNA technology concepts from a biology textbook chapter. It discusses:
1) Advances in DNA sequencing techniques have allowed researchers to sequence the genomes of extinct species like Neanderthals and woolly mammoths. Next-generation sequencing is faster and less expensive than previous methods.
2) DNA cloning and sequencing are useful tools that have applications in fields like agriculture, criminal law, and medical research. DNA cloning involves inserting a DNA fragment into a plasmid vector, which is then replicated in bacteria to produce multiple copies of the fragment.
3) DNA sequencing determines the order of nucleotides in a gene or genome. The Sanger method uses DNA polymerase and dideoxynucleotides to generate
Gene sequencing steps involved, methods used and applications pptxTanveerAhmadRather
This document provides an overview of gene sequencing. It begins with an introduction to DNA structure and the goal of gene sequencing to determine the sequence of nucleotides. It then discusses the history of gene sequencing, from early RNA sequencing to the development of Sanger and next-generation sequencing methods. The document outlines the general steps in gene sequencing and describes several specific methods, including Maxam-Gilbert, Sanger, pyrosequencing, and shotgun sequencing. It concludes by reviewing applications of gene sequencing and providing examples of species whose genomes have been sequenced.
Ch 15: The Chromosomal Basis of Inheritanceveneethmathew
1) The document summarizes a lecture on the chromosomal basis of inheritance, beginning with an overview of how genes are located on chromosomes.
2) It then discusses Mendelian inheritance having a physical basis in chromosome behavior during meiosis and fertilization. Thomas Morgan's experiments with fruit flies provided evidence linking genes to chromosomes.
3) The lecture also covers sex-linked inheritance patterns and how linked genes on the same chromosome tend to be inherited together.
1. The document discusses meiosis and sexual life cycles in biology. It provides details on the stages of meiosis, including prophase I, metaphase I, anaphase I and telophase I.
2. Meiosis results in four haploid daughter cells rather than two, and reduces the number of chromosome sets from diploid to haploid. It occurs in two divisions: meiosis I and meiosis II.
3. There are three main types of sexual life cycles that differ in the timing of meiosis and fertilization - in animals, plants and fungi. This ensures genetic variation between generations.
Viruses are small infectious particles that can only replicate inside host cells. They contain either DNA or RNA surrounded by a protein coat called a capsid, and some have an outer envelope. Viruses infect a limited range of host cells and use the cell's machinery to produce new virus particles, which are then released to infect other cells. Viruses that infect bacteria can undergo a lytic cycle that destroys the host cell or a lysogenic cycle where the viral DNA is incorporated into the host chromosome as a prophage. Retroviruses like HIV contain RNA and use reverse transcriptase to insert viral DNA into the host genome as a permanent provirus. While viruses cause many diseases, vaccines can help stimulate immunity to prevent infection
Ch 9: Cell Respiration and Fermentationveneethmathew
- Cellular respiration consists of three main stages: glycolysis, the citric acid cycle, and oxidative phosphorylation.
- Glycolysis breaks down glucose into pyruvate, generating a small amount of ATP through substrate-level phosphorylation.
- The citric acid cycle further oxidizes pyruvate and other molecules, generating more ATP and electron carriers.
- Oxidative phosphorylation generates the majority of ATP through an electron transport chain that harnesses the energy of electron transfers to power ATP synthesis.
1) Gregor Mendel conducted experiments with pea plants to study inheritance of traits from parents to offspring. Through his experiments, he discovered that traits are inherited in discrete units, which he called "factors" and which we now call genes.
2) Mendel's experiments led him to formulate two laws of inheritance: the Law of Segregation, which states that organisms inherit two copies of each gene, one from each parent, and these genes segregate or separate during the formation of gametes; and the Law of Independent Assortment, which states that different genes assort independently of one another during gamete formation.
3) Mendel's laws reflect the rules of probability - the alleles of one
Photosynthesis is the process by which plants, algae, and some bacteria use sunlight, water and carbon dioxide to produce oxygen and energy in the form of glucose. It occurs in chloroplasts and involves two stages - the light-dependent reactions where ATP and NADPH are produced, and the light-independent Calvin cycle where glucose is formed. Chlorophyll and other pigments absorb sunlight which is used to power the transfer of electrons and production of chemical energy carriers. Photosynthesis ultimately feeds the biosphere by producing organic molecules and oxygen from inorganic sources.
This document provides an overview of cellular metabolism and energy transformation. It discusses key topics including:
1) Metabolism transforms matter and energy in living cells through ordered chemical reactions. Metabolic pathways involve series of enzyme-catalyzed steps that either release (catabolism) or consume (anabolism) energy.
2) ATP is the main energy currency molecule in cells. It is regenerated through catabolic pathways and powers cellular work through exergonic hydrolysis reactions that drive endergonic processes.
3) Enzymes are protein catalysts that lower the activation energy of metabolic reactions, speeding up biochemical transformations without being consumed in the process. They confer specificity to reactions by precisely
This document provides an overview and key concepts from a lecture on the evolution of populations from Campbell Biology, 9th Edition. It discusses how natural selection acts on genetic variation within populations to drive microevolution over generations. The three main mechanisms that can alter allele frequencies in a population and lead to evolutionary change are natural selection, genetic drift, and gene flow. Natural selection is the only mechanism that consistently results in adaptive evolution. The lecture also examines examples of natural selection in Darwin's finches and provides explanations of genetic drift, the founder effect, and the bottleneck effect.
15 the chromosomal basis of inheritancekindarspirit
This document summarizes a chapter from a biology textbook about the chromosomal basis of inheritance. It discusses how Mendel's theories of heredity were later linked to chromosomes through the experiments of Thomas Hunt Morgan using fruit flies. Morgan found that a white eye color mutant in male flies was located on the X chromosome, supporting the idea that genes have specific locations on chromosomes and explaining the patterns of inheritance. The chapter outlines Mendel's laws of segregation and independent assortment and how chromosome behavior during meiosis can account for these laws.
1. The document discusses genetic engineering and biotechnology, including techniques like recombinant DNA, gene cloning, PCR, and cloning organisms.
2. Key terms defined include genetic engineering, biotechnology, recombinant DNA, gene cloning, restriction enzymes, and plasmids.
3. Recombinant DNA is made by cutting DNA with restriction enzymes and ligating pieces into plasmids, which are then inserted into bacteria.
The document discusses the chromosomal basis of inheritance. It explains that genes are located on chromosomes and Mendel's hereditary factors were genes. It describes how Morgan's experiments with fruit flies provided evidence that supported the chromosome theory of inheritance. His findings showed that genes have specific loci on chromosomes and that chromosomes segregate and assort independently during meiosis, accounting for Mendel's laws. The document also discusses sex linkage, with genes on the X chromosome being X-linked and exhibiting unique inheritance patterns. It describes how linked genes on the same chromosome tend to be inherited together but can sometimes be separated through genetic recombination via crossing over during meiosis.
This document provides an overview of a lecture on bacteria and archaea. It discusses their structural and functional adaptations that allow prokaryotes to thrive in diverse environments. Key points include:
- Prokaryotes have a variety of shapes and sizes, and cell surfaces like cell walls, capsules, and fimbriae that aid environmental interactions.
- They reproduce rapidly through binary fission and genetic diversity arises from high mutation rates and horizontal gene transfer between cells through transformation, transduction, and conjugation.
- Adaptations like motility, endospores, metabolic pathways, and rapid evolution allow prokaryotes to be highly successful and found almost everywhere on Earth.
1) The document summarizes key concepts from Chapter 24 of Campbell Biology about the origin of species. It discusses allopatric and sympatric speciation, describing how new species can form with or without geographic separation between populations.
2) Reproductive isolation is formed by prezygotic barriers that prevent mating or fertilization, and postzygotic barriers that result in non-viable or infertile hybrid offspring.
3) Examples are given of allopatric speciation including mosquitofish that evolved in isolated ponds, and snapping shrimp separated when the Isthmus of Panama formed.
The document discusses the cell cycle and cell division. It makes the following key points:
1) The cell cycle consists of interphase and the mitotic (M) phase. Interphase includes cell growth and DNA replication, while mitosis involves the equal division of genetic material into two daughter cells.
2) In eukaryotes, cell division results in two genetically identical daughter cells through mitosis and cytokinesis. Mitosis ensures each cell receives one copy of each chromosome, while cytokinesis physically separates the cytoplasmic components.
3) The stages of mitosis are prophase, prometaphase, metaphase, anaphase and telophase. During this process, chromosomes condense and
1. The document describes a lecture on phylogeny and the tree of life from Campbell Biology. It discusses how systematists use morphological and molecular data to infer evolutionary relationships and construct phylogenetic trees showing these relationships.
2. Key points include how homologies are used to determine shared ancestry, while analogies indicate convergent evolution. Maximum parsimony and maximum likelihood methods are used to evaluate potential phylogenetic trees.
3. Shared derived characters that appear for the first time in a particular clade provide evidence for which groups of species share a more recent common ancestor on the tree of life.
Gene cloning involves inserting DNA fragments from one source into plasmids or bacteria. This allows for the production of multiple copies of the gene. Restriction enzymes and DNA ligase are used to cut and paste DNA fragments into plasmids. The plasmids are then inserted into bacteria which replicate, producing many copies of the gene. Libraries of cloned DNA fragments can be stored in bacteria or plasmids. The library can be screened to identify clones containing genes of interest using probes complementary to the target gene. Expressed genes can be studied by producing their protein products in bacterial or eukaryotic cells.
04 carbon and the molecular diversity of lifekindarspirit
This document provides an overview of chapter 4 from Campbell Biology, 9th edition which discusses carbon and the molecular diversity of life. It covers how carbon is the backbone of living organisms and can form large, complex molecules like proteins, DNA, carbohydrates. It also summarizes key points about organic chemistry, the formation of carbon-carbon bonds, isomers, important functional groups in biological molecules, and how ATP is used to store energy. The document contains lecture slides with titles, images, and bullet points about these topics.
- Gregor Mendel conducted experiments breeding pea plants to study inheritance of traits from parents to offspring. He found that traits were inherited in discrete units, which we now know as genes.
- In his experiments, Mendel identified two laws of inheritance. The Law of Segregation states that genes separate during gamete formation so offspring receive only one allele for each gene from each parent. The Law of Independent Assortment states that different genes assort independently during gamete formation.
- Mendel's discoveries demonstrated that inheritance has a particulate, rather than blending, nature. His work established the foundations of classical genetics and heralded the particulate theory of inheritance.
1) Cellular respiration involves the breakdown of glucose and other organic molecules to extract energy through redox reactions in the form of ATP.
2) Glycolysis breaks down glucose into two pyruvate molecules in the cytoplasm, generating a small amount of ATP through substrate-level phosphorylation.
3) Pyruvate is further oxidized in the mitochondrion, entering the citric acid cycle which completes the oxidation of pyruvate and generates more ATP and electron carriers like NADH and FADH2.
4) Most ATP is produced through oxidative phosphorylation, as electrons from NADH and FADH2 are passed through an electron transport chain which powers ATP synthesis.
This document provides an overview of Mendelian genetics and patterns of inheritance. It discusses key topics such as:
1) Mendel's experiments with pea plants in the 1860s which discovered the fundamental principles of genetics and heredity.
2) Mendel's laws of segregation and independent assortment which explain inheritance patterns for single traits and two traits, respectively.
3) How chromosome behavior during meiosis accounts for Mendel's laws, with homologous chromosomes separating during meiosis I relating to the law of segregation, and independent assortment of chromosomes during metaphase I relating to the law of independent assortment.
This document summarizes DNA technology concepts from a biology textbook chapter. It discusses:
1) Advances in DNA sequencing techniques have allowed researchers to sequence the genomes of extinct species like Neanderthals and woolly mammoths. Next-generation sequencing is faster and less expensive than previous methods.
2) DNA cloning and sequencing are useful tools that have applications in fields like agriculture, criminal law, and medical research. DNA cloning involves inserting a DNA fragment into a plasmid vector, which is then replicated in bacteria to produce multiple copies of the fragment.
3) DNA sequencing determines the order of nucleotides in a gene or genome. The Sanger method uses DNA polymerase and dideoxynucleotides to generate
Gene sequencing steps involved, methods used and applications pptxTanveerAhmadRather
This document provides an overview of gene sequencing. It begins with an introduction to DNA structure and the goal of gene sequencing to determine the sequence of nucleotides. It then discusses the history of gene sequencing, from early RNA sequencing to the development of Sanger and next-generation sequencing methods. The document outlines the general steps in gene sequencing and describes several specific methods, including Maxam-Gilbert, Sanger, pyrosequencing, and shotgun sequencing. It concludes by reviewing applications of gene sequencing and providing examples of species whose genomes have been sequenced.
DNA sequencing methods have evolved significantly over time. Early methods like the Maxam-Gilbert chemical method and Sanger chain termination method involved laborious gel electrophoresis. Later developments led to automated Sanger sequencing using fluorescence detection. Next-generation sequencing methods like Illumina sequencing by synthesis and 454 pyrosequencing enabled massively parallel sequencing of many DNA fragments simultaneously. These new methods produce vast amounts of sequence data at lower cost and are used widely in research and applications such as agriculture, medicine, forensics, and more.
The document discusses various genomic and proteomic tools and techniques that have revolutionized the field of microbial physiology. The advent of personal computers, the Internet, and rapid DNA sequencing techniques has fueled this renaissance by enabling widespread sharing of information among scientists. Genomic tools like gene cloning and sequencing provide insights into complete genetic instructions, while proteomic techniques examine dynamic protein expression and interactions. A variety of methods are described, including two-dimensional gel electrophoresis, mass spectrometry, and gene arrays.
The document discusses different methods of DNA and protein sequencing. It begins by mentioning Sanger sequencing and chain termination sequencing. It then provides details on the principles and processes of Sanger sequencing, including how it utilizes chain terminating ddNTPs. The document discusses how Sanger sequencing was automated and led to first generation sequencing. Finally, it introduces high throughput next generation sequencing methods that allow sequencing of large genomes in a fast and cheap manner through massively parallel reactions.
Gene sequencing is the technique that determines the order of nucleotide bases in DNA. It allows researchers to read genetic information and understand genes. The first genome sequenced was a bacteriophage in 1977. Major advances include sequencing the human genome in 2001. Current technologies like Illumina and Ion Torrent can generate billions of reads faster and cheaper than Sanger sequencing. Gene sequencing has applications in medicine, forensics, agriculture, and more. It is an important tool for understanding genomes and their relationship to traits and disease.
Gene sequencing is the technique that determines the order of nucleotide bases in DNA. It allows researchers to read genetic information and understand genes. The first genome sequenced was a bacteriophage in 1977. Techniques have advanced from Sanger sequencing to second-generation sequencing using platforms like Illumina and third-generation single-molecule techniques. Gene sequencing has various applications in medicine, forensics, agriculture, cancer research and more. It is an important tool for understanding genomes and their relationship to traits and disease.
This document discusses various gene sequencing methods. It begins by introducing DNA and the importance of sequencing the genetic code. It then describes several early sequencing techniques like Sanger sequencing using chain termination or chemical cleavage. It discusses the need for sequencing to understand genetic conditions. The document also covers topics like genome sequencing, genomics, and high-throughput sequencing techniques like dye-terminator sequencing which replaced radioactive labels with fluorescent labels to automate the process.
Class9 DNA technology in secondary schoolssusera700ad
Biotechnology is the use of an organism, or a component of an organism or other biological system, to make a product or process.
Many forms of modern biotechnology rely on DNA technology.
DNA technology is the sequencing, analysis, and cutting-and-pasting of DNA.
Common forms of DNA technology include DNA sequencing, polymerase chain reaction, DNA cloning, and gel electrophoresis.
Biotechnology inventions can raise new practical concerns and ethical questions that must be addressed with informed input from all of society.
DNA sequencing determines the precise order of nucleotides in a DNA fragment. There are several methods for DNA sequencing, including the chain termination method developed by Sanger, and the Maxam-Gilbert chemical cleavage method. Next generation sequencing is now used, which allows high-throughput sequencing of entire genomes quickly and accurately using automated methods. DNA sequencing has many applications, such as identifying disease-causing genes and mutations.
Gene sequencing is the process of determining the order of nucleotides in DNA. The document discusses several generations and techniques of gene sequencing including:
1) First generation techniques like Sanger sequencing and Maxam-Gilbert sequencing that sequence individual DNA molecules.
2) Next generation sequencing techniques like pyrosequencing, sequencing by ligation, and single molecule real-time sequencing that allow high-throughput parallel sequencing of many DNA fragments.
3) The document provides details on the workflow and chemistry employed by several modern sequencing platforms like Illumina, Roche 454, and Pacific Biosciences. Whole genome shotgun, double barrel shotgun, and hierarchical shotgun are also summarized as strategies for genome sequencing.
DNA sequencing involves determining the order of nucleotides (adenine, guanine, cytosine, thymine) in a DNA molecule. There are three main methods: 1) Maxam-Gilbert chemical degradation, 2) Sanger dideoxynucleotide chain termination, and 3) direct sequencing using PCR. Gene synthesis chemically builds DNA base-by-base without a template, and has applications in forensics, agriculture, and solving crimes.
DNA microarrays, also known as DNA chips, allow researchers to analyze large numbers of DNA sequences simultaneously. They contain thousands of unique DNA probes immobilized on a solid surface in an organized grid pattern. Unknown DNA samples are labeled with fluorescent dyes and hybridized to the probes on the chip. The bound DNA is then detected using lasers and analyzed by a computer to determine which genes are present or expressed in the sample. There are two main types of DNA chips - cDNA-based chips containing amplified cDNA probes, and oligonucleotide-based chips containing short, synthesized DNA sequences. DNA microarrays have many applications including gene expression profiling, comparative genomics, disease diagnosis, and drug discovery.
Polymerase chain reaction (PCR) is an in vitro technique used to amplify specific DNA sequences. It involves repeated cycles of heating and cooling of the DNA sample to separate and copy the DNA strands. Key components of PCR include DNA primers, DNA template, DNA polymerase, deoxynucleotides, and buffer. Through multiple cycles of denaturation, annealing and extension, a single copy of DNA can be exponentially amplified to generate thousands or millions of copies. PCR has numerous applications in fields such as genetics, medicine, forensics and environmental testing due to its ability to amplify small amounts of DNA.
dna sequencing is the one of the most important technique in today's biotech field and in this ppt I cover up the most imporatant techniques of DNA sequencing methods
The document discusses DNA technology and polymerase chain reaction (PCR). It begins by explaining DNA sequencing techniques like Sanger sequencing. It then describes the development of PCR by Kary Mullis in 1985. PCR allows for rapid amplification of specific DNA sequences and has revolutionized fields like forensics, ancient DNA analysis, disease detection, and more. It works by cycling between high and low temperatures to denature and copy DNA using primers and DNA polymerase. The document outlines the components and steps of PCR and factors that influence it.
Detailed explanation about gene sequencing methods
Sequencing the gene is an important step toward understanding the gene.
A gene sequence contains some clues about where genes are.
Gene sequencing give us understanding how the genome as a whole works-how genes work together to direct the growth, development and maintenance of an entire organism.
It help scientists to study the part of genome outside the genes-regulatory regions
DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, guanine, cytosine, and thymine.
Similar to Campbell Biology 10th edition ( PDFDrive ).pdf (20)
1. Charles Darwin was a British naturalist who developed the theory of evolution by natural selection after observing species diversity during a five-year voyage.
2. His observations of mockingbirds and other species on the Galapagos Islands led him to hypothesize that organisms could diversify into new species when isolated on different islands.
3. Darwin published his theory of evolution by natural selection in 1859 in his book On the Origin of Species, wherein he argued that variations within a species provided different chances of survival and reproduction in their environment.
Sir Syed Ahmad Khan was a 19th century Indian scholar and reformer who founded the Muhammadan Anglo-Oriental College, now known as Aligarh Muslim University. After the Indian Rebellion of 1857, he advocated for Muslims to loyally serve the British and to focus on education in order to empower themselves. He formed groups to promote science, education and political awareness among Indian Muslims. He advised Muslims to stay out of politics initially and focus on acquiring modern education and skills.
The Khilafat movement was a religious movement launched in the Indian subcontinent to protect the Ottoman Empire, which was captured by the British government after World War I. It was started in 1919 by Ali brothers Maulana Muhammad Ali Johr and Shaukat Ali in response to the Allied powers defeating the Ottoman Empire in World War I. The goals of the movement were to preserve the territorial integrity of the Ottoman Empire, maintain control of holy places by Muslims, and oppose the Treaty of Severes which divided former Ottoman lands. Hindus also participated for a time under Gandhi's leadership through non-violent non-cooperation with British rule. However, the movement ended after the Chauri Chaura incident of violence caused Gand
The document discusses the morphology and modifications of roots in plants. It describes the main regions and functions of typical roots, including the root cap, meristematic region, region of elongation, region of root hairs, and region of maturation. It also discusses two main root systems - tap roots and adventitious roots. Tap roots develop from the radicle and form a main tap root with branches. Adventitious roots develop from other parts like stems and leaves. Some roots are modified for specialized functions like storage, respiration, support, and parasitism.
The arrival of Islam in South Asia began through trade contacts between Arab traders and parts of southern India in the early centuries CE. As these traders adopted Islam, they helped spread the new religion. The Muslim conquest of Sindh by Muhammad bin Qasim in 711 CE marked the first establishment of Muslim political rule in the region. Bin Qasim's successful campaign was launched in response to attacks on Arab merchant ships by pirates based in Sindh. Overall, Islam spread both peacefully through Sufi missionaries and merchants as well as through subsequent military campaigns by Turkic dynasties between 1000-1526 CE. The new religion had a significant impact on the culture and society of South Asia, influencing language
The biosphere consists of all ecosystems and living organisms on Earth, spanning from deep underground to high in the atmosphere. It originated around 3.5 billion years ago as primitive prokaryotes developed photosynthesis, producing oxygen and enabling more complex lifeforms. The biosphere benefits from nutrient recycling within food webs and exchanges between the lithosphere, hydrosphere, and atmosphere. To help maintain this balance, the UN established biosphere reserves to foster sustainable relationships between human activities and natural environments.
Sedimentary rocks form from the consolidation of sediments and are divided into clastic, chemical, and biochemical types. Clastic rocks like sandstone and shale form from weathered fragments transported by wind, water, or ice. Chemical rocks like limestone precipitate directly from solution. Biochemical rocks such as coal form from the remains of living organisms. Sedimentary structures and fossils within rocks provide clues about depositional environments. Sedimentary rocks are economically important resources for construction materials, energy, and industrial minerals.
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.
LAND USE LAND COVER AND NDVI OF MIRZAPUR DISTRICT, UPRAHUL
This Dissertation explores the particular circumstances of Mirzapur, a region located in the
core of India. Mirzapur, with its varied terrains and abundant biodiversity, offers an optimal
environment for investigating the changes in vegetation cover dynamics. Our study utilizes
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analyze the transformations that have taken place over the course of a decade.
The complex relationship between human activities and the environment has been the focus
of extensive research and worry. As the global community grapples with swift urbanization,
population expansion, and economic progress, the effects on natural ecosystems are becoming
more evident. A crucial element of this impact is the alteration of vegetation cover, which plays a
significant role in maintaining the ecological equilibrium of our planet.Land serves as the foundation for all human activities and provides the necessary materials for
these activities. As the most crucial natural resource, its utilization by humans results in different
'Land uses,' which are determined by both human activities and the physical characteristics of the
land.
The utilization of land is impacted by human needs and environmental factors. In countries
like India, rapid population growth and the emphasis on extensive resource exploitation can lead
to significant land degradation, adversely affecting the region's land cover.
Therefore, human intervention has significantly influenced land use patterns over many
centuries, evolving its structure over time and space. In the present era, these changes have
accelerated due to factors such as agriculture and urbanization. Information regarding land use and
cover is essential for various planning and management tasks related to the Earth's surface,
providing crucial environmental data for scientific, resource management, policy purposes, and
diverse human activities.
Accurate understanding of land use and cover is imperative for the development planning
of any area. Consequently, a wide range of professionals, including earth system scientists, land
and water managers, and urban planners, are interested in obtaining data on land use and cover
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cover support policymakers and scientists in making well-informed decisions, as alterations in
these patterns indicate shifts in economic and social conditions. Monitoring such changes with the
help of Advanced technologies like Remote Sensing and Geographic Information Systems is
crucial for coordinated efforts across different administrative levels. Advanced technologies like
Remote Sensing and Geographic Information Systems
9
Changes in vegetation cover refer to variations in the distribution, composition, and overall
structure of plant communities across different temporal and spatial scales. These changes can
occur natural.
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
Reimagining Your Library Space: How to Increase the Vibes in Your Library No ...Diana Rendina
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Chapter wise All Notes of First year Basic Civil Engineering
Syllabus
Chapter-1
Introduction to objective, scope and outcome the subject
Chapter 2
Introduction: Scope and Specialization of Civil Engineering, Role of civil Engineer in Society, Impact of infrastructural development on economy of country.
Chapter 3
Surveying: Object Principles & Types of Surveying; Site Plans, Plans & Maps; Scales & Unit of different Measurements.
Linear Measurements: Instruments used. Linear Measurement by Tape, Ranging out Survey Lines and overcoming Obstructions; Measurements on sloping ground; Tape corrections, conventional symbols. Angular Measurements: Instruments used; Introduction to Compass Surveying, Bearings and Longitude & Latitude of a Line, Introduction to total station.
Levelling: Instrument used Object of levelling, Methods of levelling in brief, and Contour maps.
Chapter 4
Buildings: Selection of site for Buildings, Layout of Building Plan, Types of buildings, Plinth area, carpet area, floor space index, Introduction to building byelaws, concept of sun light & ventilation. Components of Buildings & their functions, Basic concept of R.C.C., Introduction to types of foundation
Chapter 5
Transportation: Introduction to Transportation Engineering; Traffic and Road Safety: Types and Characteristics of Various Modes of Transportation; Various Road Traffic Signs, Causes of Accidents and Road Safety Measures.
Chapter 6
Environmental Engineering: Environmental Pollution, Environmental Acts and Regulations, Functional Concepts of Ecology, Basics of Species, Biodiversity, Ecosystem, Hydrological Cycle; Chemical Cycles: Carbon, Nitrogen & Phosphorus; Energy Flow in Ecosystems.
Water Pollution: Water Quality standards, Introduction to Treatment & Disposal of Waste Water. Reuse and Saving of Water, Rain Water Harvesting. Solid Waste Management: Classification of Solid Waste, Collection, Transportation and Disposal of Solid. Recycling of Solid Waste: Energy Recovery, Sanitary Landfill, On-Site Sanitation. Air & Noise Pollution: Primary and Secondary air pollutants, Harmful effects of Air Pollution, Control of Air Pollution. . Noise Pollution Harmful Effects of noise pollution, control of noise pollution, Global warming & Climate Change, Ozone depletion, Greenhouse effect
Text Books:
1. Palancharmy, Basic Civil Engineering, McGraw Hill publishers.
2. Satheesh Gopi, Basic Civil Engineering, Pearson Publishers.
3. Ketki Rangwala Dalal, Essentials of Civil Engineering, Charotar Publishing House.
4. BCP, Surveying volume 1
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
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This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
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The event will cover the following::
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Special TechSoup offer for a free 180 days membership, and up to $150 in discounts on eligible orders.
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Walmart Business+ and Spark Good for Nonprofits.pdf
Campbell Biology 10th edition ( PDFDrive ).pdf
1. Chapter 19
DNA Biotechnology
Lecture on General Biology 2
Chul-Su Yang, Ph.D., chulsuyang@hanyang.ac.kr
Infection Biology Lab., Dept. of Molecular & Life Science, Hanyang University
Campbell Biology 10th edition
A Global Approach
2. • Sequencing of the genomes of more than 7,000
species was under way in 2010
• DNA sequencing has depended on advances in
technology, starting with making recombinant DNA
• In recombinant DNA, nucleotide sequences from
two different sources, often two species, are
combined in vitro into the same DNA molecule
Overview
The DNA Toolbox
3. • Recently the genome sequences of two extinct
species—Neanderthals and wooly mammoths—
have been completed
• Advances in sequencing techniques make
genome sequencing increasingly faster and
less expensive
5. Figure 19.1a
The New Yorker, August 15, 2011
Annals of Evolution
What happened between the Neanderthals and us?
6. • Methods for making recombinant DNA are central
to genetic engineering, the direct manipulation of
genes for practical purposes
• DNA technology has revolutionized
biotechnology, the manipulation of organisms or
their genetic components to make useful products
• An example of DNA technology is the microarray,
a measurement of gene expression of thousands
of different genes
• The applications of DNA technology affect
everything from agriculture, to criminal law,
to medical research
7. • The complementarity of the two DNA strands is
the basis for nucleic acid hybridization, the base
pairing of one strand of nucleic acid to the
complementary sequence on another strand
• Genetic engineering is the direct manipulation of
genes for practical purposes
Concept 19.1
DNA sequencing and DNA cloning are valuable tools
for genetic engineering and biological inquiry
8. DNA Sequencing
• Researchers can exploit the principle of
complementary base pairing to determine a
gene’s complete nucleotide sequence, called
DNA sequencing
• The first automated procedure was based on a
technique called dideoxy or chain termination
sequencing, developed by Sanger
9. DNA Sequencing
• Relatively short DNA fragments can be sequenced
by the dideoxy chain termination method, the first
automated method to be employed
• Modified nucleotides called
dideoxyribonucleotides (ddNTP) attach to
synthesized DNA strands of different lengths
• Each type of ddNTP is tagged with a distinct
fluorescent label that identifies the nucleotide at
the end of each DNA fragment
• The DNA sequence can be read from the resulting
spectrogram
11. Figure 19.3
DNA
(template strand)
TECHNIQUE
5′
3′
C
C
C
C
T
T
T
G
G
A
A
A
A
G
T
T
T
DNA
polymerase
Primer
5′
3′
P P P
OH
G
dATP
dCTP
dTTP
dGTP
Deoxyribonucleotides Dideoxyribonucleotides
(fluorescently tagged)
P P P
H
G
ddATP
ddCTP
ddTTP
ddGTP
5′
3′
C
C
C
C
T
T
T
G
G
A
A
A
A
DNA (template
strand)
Labeled strands
Shortest Longest
5′
3′
ddC
ddG
ddA
ddA
ddA
ddG
ddG
ddT
ddC
G
T
T
T
G
T
T
T
C
G
T
T
T
C
T T
G
G
T
T
T
C
T
G
A
G
T
T
T
C
T
G
A
A
G
T
T
T
C
T
G
A
A
G
G
T
T
T
C
T
G
A
A
G
T
G
T
T
T
C
T
G
A
A
G
T
C
G
T
T
T
C
T
G
A
A
G
T
C
A
Direction
of movement
of strands
Longest labeled strand
Detector
Laser
Shortest labeled strand
RESULTS
Last nucleotide
of longest
labeled strand
Last nucleotide
of shortest
labeled strand
G
G
G
A
A
A
C
C
T
12. Figure 19.3a
DNA
(template strand)
TECHNIQUE
Primer Deoxyribonucleotides Dideoxyribonucleotides
(fluorescently tagged)
DNA
polymerase
5′
5′
3′
3′
OH H
G
G
dATP
dCTP
dTTP
dGTP
P P P P P P
ddATP
ddCTP
ddTTP
ddGTP
T
T
T
G
G
G
C
C
C
C
T
T
T
A
A
A
A
13. Figure 19.3b
DNA (template
strand)
Labeled strands
Shortest Longest
Direction
of movement
of strands
Longest labeled strand
Detector
Laser
Shortest labeled strand
TECHNIQUE (continued)
5′
3′
G
G
C
C
C
C
T
T
T
A
A
A
A
T
T
T
G
ddC
ddC
ddG
ddG
ddG
ddA
ddA
ddA
ddT
3′
5′
T
T
T
G
C
T
T
T
G
C
G
T
T
T
G
C
G
A
T
T
T
G
C
G
A
A
T
T
T
G
C
G
A
A
G
T
T
T
C
G
A
A
G
T
T
T
T
C
G
A
A
G
T
C
A
T
T
T
C
G
A
A
G
T
C
G G G
14. Figure 19.3c
RESULTS
Last nucleotide
of longest
labeled strand
Last nucleotide
of shortest
labeled strand
G
G
G
A
A
A
C
C
T
Direction
of movement
of strands
Longest labeled strand
Detector
Laser
Shortest labeled strand
15. • “Next-generation sequencing” techniques use a
single template strand that is immobilized and
amplified to produce an enormous number of
identical fragments
• Thousands or hundreds of thousands of
fragments (400–1,000 nucleotides long) are
sequenced in parallel
• This is a type of “high-throughput” technology
16. Figure 19.4 Technique
Genomic DNA is fragmented.
Each fragment is isolated with
a bead.
Using PCR, 106 copies of each
fragment are made, each attached
to the bead by 5′ end.
The bead is placed into a well with
DNA polymerases and primers.
A solution of each of the four nucleotides
is added to all wells and then washed off.
The entire process is then repeated.
If a nucleotide is joined to
a growing strand, PPi is
released, causing a flash
of light that is recorded.
If a nucleotide is not
complementary to the
next template base,
no PPi is released, and
no flash of light is recorded.
The process is repeated until every
fragment has a complete complementary
strand. The pattern of flashes reveals the
sequence.
Results
6 7 8
5
4
3
2
1
4-mer
3-mer
2-mer
1-mer
A
T
G
C
Template strand
of DNA
Primer
3′
A
3′
5′ 5′
T G C
A T G C A T G C A T G C A T G C
Template
strand
of DNA
Primer
DNA
polymerase
dATP
dTTP dGTP dCTP
PPi
PPi
C
C
C
C
A
A
A
A
T
T
T
G
G
G
G
C
C
C
C
A
A
A
A
T
T
T
G
G
G
G
C
C
C
C
A
A
A
A
T
T
T
G
G
G
G
C
C
C
C
A
A
A
A
T
T
T
G
G
G
G
A A A A
C
17. Figure 19.4a
Technique
Genomic DNA is fragmented.
Each fragment is isolated with
a bead.
Using PCR, 106 copies of each
fragment are made, each attached
to the bead by 5′ end.
The bead is placed into a well with
DNA polymerases and primers.
4
Template strand
of DNA
Primer
3′
A
3′
5′ 5′
T G C
3
2
1
5 A solution of each of the four nucleotides
is added to all wells and then washed off.
The entire process is then repeated.
18. Figure 19.4b
6 7
If a nucleotide is joined to
a growing strand, PPi is
released, causing a flash
of light that is recorded.
If a nucleotide is not
complementary to the
next template base,
no PPi is released, and
no flash of light is recorded.
Template
strand
of DNA
Primer
DNA
polymerase
dATP
dTTP
PPi
C
C
C
C
A
A
A
A
T
T
T
G
G
G
G
Technique
A T G C A T G C
A
C
C
C
C
A
A
A
A
T
T
T
G
G
G
G
A
19. 8
Technique
A T G C A T G C
C
C
C
C
A
A
A
A
T
T
T
G
G
G
G
C
C
C
C
A
A
A
A
T
T
T
G
G
G
G
A A
C
dGTP dCTP
PPi
The process is repeated until every
fragment has a complete complementary
strand. The pattern of flashes reveals the
sequence.
Figure 19.4c
Results
4-mer
3-mer
2-mer
1-mer
A
T
G
C
20. • In “third-generation sequencing,” the techniques
used are even faster and less expensive than the
previous
21. Making Multiple Copies of a Gene or Other
DNA Segment
• To work directly with specific genes, scientists
prepare well-defined segments of DNA in identical
copies, a process called DNA cloning
• Plasmids are small circular DNA molecules that
replicate separately from the bacterial
chromosome
• Researchers can insert DNA into plasmids to
produce recombinant DNA, a molecule with
DNA from two different sources
22. DNA Cloning and Its Applications:
A Preview
• Most methods for cloning pieces of DNA in the
laboratory share general features, such as the use
of bacteria and their plasmids
• Cloned genes are useful for making copies of a
particular gene and producing a protein product
23. • Gene cloning involves using bacteria to make
multiple copies of a gene
• Foreign DNA is inserted into a plasmid, and the
recombinant plasmid is inserted into a bacterial
cell
• Reproduction in the bacterial cell results in cloning
of the plasmid including the foreign DNA
• This results in the production of multiple copies of
a single gene
24. Figure 19.5a
Bacterium
Bacterial
chromosome
Plasmid
2
1 Gene inserted into
plasmid
Cell containing
gene of interest
Recombinant
DNA (plasmid)
Gene of
interest
Plasmid put into
bacterial cell
DNA of
chromosome
(“foreign” DNA)
Recombinant
bacterium
25. Figure 19.5b
Host cell grown in
culture to form a clone
of cells containing the
“cloned” gene of interest
Gene of
interest
Protein expressed from
gene of interest
Protein harvested
Copies of gene
Basic research
and various
applications
3
4
Basic
research
on protein
Basic
research
on gene
Gene for pest
resistance inserted
into plants
Gene used to alter
bacteria for cleaning
up toxic waste
Protein dissolves
blood clots in heart
attack therapy
Human growth
hormone treats
stunted growth
26. • A plasmid used to clone a foreign gene is called a
cloning vector
• Bacterial plasmids are widely used as cloning
vectors because they are readily obtained, easily
manipulated, easily introduced into bacterial cells,
and once in the bacteria they multiply rapidly
• Gene cloning is useful for amplifying genes to
produce a protein product for research, medical,
or other purposes
27. Using Restriction Enzymes to Make
Recombinant DNA
• Bacterial restriction enzymes cut DNA
molecules at specific DNA sequences called
restriction sites
• A restriction enzyme usually makes many cuts,
yielding restriction fragments
• The most useful restriction enzymes cut DNA in a
staggered way, producing fragments with “sticky
ends.”
28. • Sticky ends can bond with complementary sticky
ends of other fragments
• DNA ligase is an enzyme that seals the bonds
between restriction fragments
29. Figure 19.6
Bacterial
plasmid
Restriction site
DNA
Restriction enzyme cuts
the sugar-phosphate
backbones at each arrow.
1
Base pairing of sticky
ends produces various
combinations.
2
DNA ligase
seals the strands.
3
Sticky end
Fragment from different DNA molecule
cut by the same restriction enzyme
One possible combination
Recombinant DNA molecule
5′
5′
5′
5′
5′
5′
5′
5′
3′
3′
3′
3′
3′
3′
3′
3′
3′
3′ 3′
3′
3′
3′
3′
3′
5′ 5′ 5′
5′
5′ 5′
5′
5′
G AATT C
G
A
A
T
T
C
G AATT C
G
A
A
T
T
C
Recombinant
plasmid
GAATTC
CTTAAG
30. Cloning a Eukaryotic Gene in a
Bacterial Plasmid
• In gene cloning, the original plasmid is called a
cloning vector
• A cloning vector is a DNA molecule that can carry
foreign DNA into a host cell and replicate there
31. Producing Clones of Cells Carrying
Recombinant Plasmids
• Several steps are required to clone the
hummingbird β-globin gene in a bacterial plasmid
– The hummingbird genomic DNA and a bacterial
plasmid are isolated
– Both are cut with the same restriction enzyme
– The fragments are mixed, and DNA ligase is
added to bond the fragment sticky ends
32. – Some recombinant plasmids now contain
hummingbird DNA
– The DNA mixture is added to bacteria that have
been genetically engineered to accept it
– The bacteria are plated on a type of agar that
selects for the bacteria with recombinant
plasmids
– This results in the cloning of many hummingbird
DNA fragments, including the β-globin gene
33. Research Method: Cloning Genes in Bacterial Plasmids
Bacterial plasmid
TECHNIQUE
ampR gene lacZ gene
Restriction
site
Hummingbird cell
Sticky
ends Gene of
interest
Humming-
bird DNA
fragments
Recombinant plasmids Nonrecombinant
plasmid
Bacteria carrying
plasmids
35. Storing Cloned Genes in DNA Libraries
• A genomic library that is made using bacteria is
the collection of recombinant vector clones
produced by cloning DNA fragments from an
entire genome
• A genomic library that is made using
bacteriophages is stored as a collection of phage
clones
36. Genomic libraries
Foreign genome
Cut with restriction enzymes into either
small
fragments
large
fragments
or
Recombinant
plasmids
Plasmid
clone
(a) Plasmid library
(b) BAC clone
Bacterial artificial
chromosome (BAC)
Large
insert
with
many
genes
(c) Storing genome libraries
37. • A bacterial artificial chromosome (BAC) is a
large plasmid that has been trimmed down and
can carry a large DNA insert
• BACs are another type of vector used in DNA
library construction
38. • A complementary DNA (cDNA) library is made
by cloning DNA made in vitro by reverse
transcription of all the mRNA produced by a
particular cell
• A cDNA library represents only part of the
genome—only the subset of genes transcribed
into mRNA in the original cells
39. Making cDNA from
eukaryotic genes
DNA in
nucleus
mRNAs in
cytoplasm
mRNA
Reverse
transcriptase Poly-A tail
DNA
strand
Primer
DNA
polymerase
cDNA
5′
5′
5′
5′
5′
5′
5′
5′
3′
3′
3′
3′
3′
3′
3′
3′
A A A A A A
A A A A A A
T T T T T
T T T T T
Figure 19.11
40. Screening a Library for Clones Carrying
a Gene of Interest
• A clone carrying the gene of interest can be
identified with a nucleic acid probe having a
sequence complementary to the gene
• This process is called nucleic acid hybridization
41. • A probe can be synthesized that is
complementary to the gene of interest
• For example, if the desired gene is
– Then we would synthesize this probe
5′ 3′
⋅⋅⋅ CTCATCACCGGC⋅⋅⋅
5′
3′ GAGTAGTGGCCG
42. • The DNA probe can be used to screen a large
number of clones simultaneously for the gene of
interest
• Once identified, the clone carrying the gene of
interest can be cultured
43. Research Method: Detecting a Specific DNA Sequence by
Hybridization with a Nucleic Acid Probe
Radioactively
labeled probe
molecules Gene of
interest
Probe
DNA
Single-
stranded
DNA from
cell
Film
Location of
DNA with the
complementary
sequence
Nylon
membrane
Nylon membrane
Multiwell plates
holding library
clones
TECHNIQUE 5′
5′
3′
3′
GAGTAGTGGCCG
⋅⋅⋅CTCATCACCGGC⋅⋅⋅
Denature the DNA,
the resulting
ssDNA to the
membrane
44. • A technique called Southern blotting combines
gel electrophoresis of DNA fragments with nucleic
acid hybridization
• Specific DNA fragments can be identified by
Southern blotting, using labeled probes that
hybridize to the DNA immobilized on a “blot” of gel
45. Research Method: Southern Blotting of DNA Fragments
DNA + restriction enzyme
3
2
1
4
TECHNIQUE
I Normal
β-globin
allele
II Sickle-cell
allele
III Heterozygote
Restriction
fragments
Nitrocellulose
membrane (blot)
Heavy
weight
Gel
Sponge
Alkaline
solution Paper
towels
II
I III
II
I III II
I III
Preparation of
restriction fragments
Gel electrophoresis DNA transfer (blotting)
Radioactively labeled
probe for β-globin
gene
Nitrocellulose blot
Probe base-pairs
with fragments
Fragment from
sickle-cell
β-globin allele
Fragment from
normal β- globin
allele
Film
over
blot
Hybridization with labeled probe Probe detection
5
46. Gel Electrophoresis and Southern Blotting
• One indirect method of rapidly analyzing and
comparing genomes is gel electrophoresis
• This technique uses a gel as a molecular sieve to
separate nucleic acids or proteins by size,
electrical charge, and other properties
• A current is applied that causes charged
molecules to move through the gel
• Molecules are sorted into “bands” by their size
47. Using restriction fragment analysis to distinguish the normal and sickle-cell
alleles of the human β-globin gene
Normal β-globin allele
Sickle-cell mutant β-globin allele
(a) DdeI restriction sites in normal and
sickle-cell alleles of the β-globin gene
201 bp
175 bp
376 bp
Large fragment
Large fragment
DdeI DdeI DdeI DdeI
DdeI DdeI DdeI
48. Large
fragment
Normal
allele
Sickle-cell
allele
201 bp
175 bp
376 bp
(b) Electrophoresis of restriction
fragments from normal and
sickle-cell alleles
Using restriction fragment analysis to distinguish the normal and sickle-cell
alleles of the human β-globin gene
49. • To check the recombinant plasmid, researchers
might cut the products again using the same
restriction enzyme
• To separate and visualize the fragments
produced, gel electrophoresis would be carried
out
• This technique uses a gel made of a polymer to
separate a mixture of nucleic acids or proteins
based on size, charge, or other physical
properties
50. Figure 19.7
Anode
Cathode
Wells
Gel
Mixture of
DNA mol-
ecules of
different
sizes
(a) Negatively charged DNA molecules move
toward the positive electrode.
Power
source
(b) Shorter molecules are slowed down less than
longer ones, so they move faster through the gel.
Restriction fragments
(size standards)
51. Amplifying DNA in Vitro: The
Polymerase Chain Reaction (PCR)
• The polymerase chain reaction, PCR, can
produce many copies of a specific target segment
of DNA
• A three-step cycle—heating, cooling, and
replication—brings about a chain reaction that
produces an exponentially growing population of
identical DNA molecules
• The key to PCR is an unusual, heat-stable DNA
polymerase called Taq polymerase.
52. • PCR uses a pair of primers specific for the
sequence to be amplified
• PCR amplification occasionally incorporates
errors into the amplified strands and so cannot
substitute for gene cloning in cells
54. • PCR primers can be designed to include
restriction sites that allow the product to be
cloned into plasmid vectors
• The resulting clones are sequenced and
error-free inserts selected
55. Figure 19.9
DNA fragments obtained
by PCR with restriction
sites matching those in
the cloning vector
Cut with same restriction
enzyme used on cloning
vector
A gene that makes bacterial
cells resistant to an antibiotic
is present on the plasmid.
Cloning vector
(bacterial plasmid)
Only cells that take up
a plasmid will survive
Mix and ligate
Recombinant
DNA plasmid
56. Expressing Cloned Eukaryotic Genes
• After a gene has been cloned, its protein product
can be produced in larger amounts for research
• Cloned genes can be expressed as protein in
either bacterial or eukaryotic cells
57. Bacterial Expression Systems
• Several technical difficulties hinder expression of
cloned eukaryotic genes in bacterial host cells
• To overcome differences in promoters and other
DNA control sequences, scientists usually employ
an expression vector, a cloning vector that
contains a highly active bacterial promoter
58. • Another difficulty with eukaryotic gene expression
in bacteria is the presence of introns in most
eukaryotic genes
• Researchers can avoid this problem by using
cDNA, complementary to the mRNA, which
contains only exons
59. Eukaryotic Cloning and Expression
Systems
• Molecular biologists can avoid eukaryote-bacterial
incompatibility issues by using eukaryotic cells,
such as yeasts, as hosts for cloning and
expressing genes
• Even yeasts may not possess the proteins
required to modify expressed mammalian proteins
properly
• In such cases, cultured mammalian or insect cells
may be used to express and study proteins
60. • One method of introducing recombinant DNA into
eukaryotic cells is electroporation, applying a
brief electrical pulse to create temporary holes in
plasma membranes
• Alternatively, scientists can inject DNA into cells
using microscopically thin needles
• Once inside the cell, the DNA is incorporated into
the cell’s DNA by natural genetic recombination
61. • In restriction fragment analysis, DNA fragments
produced by restriction enzyme digestion of a
DNA molecule are sorted by gel electrophoresis
• Restriction fragment analysis can be used to
compare two different DNA molecules, such as
two alleles for a gene if the nucleotide difference
alters a restriction site
62. • Variations in DNA sequence are called
polymorphisms
• Sequence changes that alter restriction sites are
called RFLPs (restriction fragment length
polymorphisms)
63. Cross-Species Gene Expression and
Evolutionary Ancestry
• The remarkable ability of bacteria to express some
eukaryotic proteins underscores the shared
evolutionary ancestry of living species
• For example, Pax-6 is a gene that directs
formation of a vertebrate eye; the same gene in
flies directs the formation of an insect eye (which
is quite different from the vertebrate eye)
• The Pax-6 genes in flies and vertebrates can
substitute for each other
64. • DNA cloning allows researchers to
– Compare genes and alleles between individuals
– Locate gene expression in a body
– Determine the role of a gene in an organism
• Several techniques are used to analyze the DNA
of genes
• Analysis of when and where a gene or group of
genes is expressed can provide important clues
about gene function
Concept 19.2
Biologists use DNA technology to study gene
expression and function
65. Analyzing Gene Expression
• The most straightforward way to discover which
genes are expressed in certain cells is to identify
the mRNAs being made
• Nucleic acid probes can hybridize with mRNAs
transcribed from a gene
• Probes can be used to identify where or when a
gene is transcribed in an organism
66. Studying the Expression of Single Genes
• Changes in the expression of a gene during
embryonic development can be tested using
– Northern blotting
– Reverse transcriptase-polymerase chain reaction
• Both methods are used to compare mRNA from
different developmental stages
• The most straightforward way to discover which
genes are expressed in certain cells is to identify
the mRNAs being made
67. • Northern blotting combines gel electrophoresis
of mRNA followed by hybridization with a probe on
a membrane
• Identification of mRNA at a particular
developmental stage suggests protein function at
that stage
• mRNA can be detected by nucleic acid
hybridization with complementary molecules
• These complementary molecules, of either DNA or
RNA, are nucleic acid probes
68. • In situ hybridization uses fluorescent dyes
attached to probes to identify the location of
specific mRNAs in place in the intact organism
Figure 19.10
50 µm
69. Figure 19.10
Head
50 µm
Thorax Abdomen
Segment
boundary
Head Thorax Abdomen
T1 T2 T3 A1 A2 A3 A4 A5
5′ 3′
3′
3′
3′
5′ 5′
5′
TAACGGTTCCAGC
ATTGCCAAGGTCG
CTCAAGTTGCTCT
GAGTTCAACGAGA
Cells
expressing
the wg gene
Cells
expressing
the en gene
wg mRNA en mRNA
70. • Reverse transcriptase-polymerase chain
reaction (RT-PCR) is quicker and more sensitive
because it requires less mRNA than Northern
blotting
• Reverse transcriptase is added to mRNA to make
complementary DNA (cDNA), which serves as a
template for PCR amplification of the gene of
interest
• The products are run on a gel and the mRNA of
interest identified
71. Figure 19.11
DNA in
nucleus
mRNAs in
cytoplasm
Reverse transcriptase
Poly-A tail
mRNA
DNA
strand
Primer
(poly-dT)
5′
5′
5′
5′
3′
3′
3′
3′
A A A A A A
A A A A A A
T T T T T
T T T T T
5′
3′ 5′
3′
DNA
polymerase
5′
3′ 5′
3′
cDNA
73. Studying the Expression of
Interacting Groups of Genes
• Automation has allowed scientists to measure
expression of thousands of genes at one time
using DNA microarray assays
• DNA microarray assays compare patterns of
gene expression in different tissues, at different
times, or under different conditions
74. Isolate mRNA.
2
1
3
4
TECHNIQUE
Make cDNA by reverse
transcription, using
fluorescently labeled
nucleotides.
Apply the cDNA mixture to a
microarray, a different gene
in each spot. The cDNA hybridizes
with any complementary DNA on
the microarray.
Rinse off excess cDNA; scan microarray
for fluorescence. Each fluorescent spot
(yellow) represents a gene expressed
in the tissue sample.
Tissue sample
mRNA molecules
Labeled cDNA molecules
(single strands)
DNA fragments
representing a
specific gene
DNA microarray
DNA microarray
with 2,400
human genes
Research Method: DNA Microarray Assay of Gene Expression Levels
75. Figure 19.13
Genes expressed
in first tissue.
Genes expressed
in second tissue.
Genes expressed
in both tissues.
Genes expressed
in neither tissue.
DNA microarray
(actual size)
Each dot is a well containing identical copies
of DNA fragments that carry a specific gene.
►
76. • With rapid and inexpensive sequencing methods
available, researchers can also just sequence
cDNA samples from different tissues or
embryonic stages to determine the gene
expression differences between them
• By uncovering gene interactions and clues to
gene function DNA microarray assays may
contribute to understanding of disease and
suggest new diagnostic targets
77. Determining Gene Function
• One way to determine function is to disable the
gene and observe the consequences
• Using in vitro mutagenesis, mutations are
introduced into a cloned gene, altering or
destroying its function
• When the mutated gene is returned to the cell, the
normal gene’s function might be determined by
examining the mutant’s phenotype
78. • Gene expression can also be silenced using RNA
interference (RNAi)
• Synthetic double-stranded RNA molecules
matching the sequence of a particular gene are
used to break down or block the gene’s mRNA
79. • In humans, researchers analyze the genomes of
many people with a certain genetic condition to try
to find nucleotide changes specific to the condition
• These genome-wide association studies test for
genetic markers, sequences that vary among
individuals
• Genetic markers called SNPs (single nucleotide
polymorphisms) occur on average every 100–
300 base pairs
• SNPs can be detected by PCR, and any SNP
shared by people affected with a disorder but not
among unaffected people may pinpoint the
location of the disease-causing gene
80. • SNP variants that are found frequently associated
with a particular inherited disorder alert
researchers to the most likely location for the
disease-causing gene
• SNPs are rarely directly involved in the disease;
they are most often in noncoding regions of the
genome
82. • Organismal cloning produces one or more
organisms genetically identical to the “parent” that
donated the single cell
• A stem cell is a relatively unspecialized cell that
can reproduce itself indefinitely, or under certain
conditions can differentiate into one or more types
of specialized cells
Concept 19.3
Cloned organisms and stem cells are useful for
basic research and other applications
83. Cloning Plants: Single-Cell Cultures
• One experimental approach for testing genomic
equivalence is to see whether a differentiated cell
can generate a whole organism
• In plants, cells can de differentiate and then
give rise to all the specialized cell types of
the organism
• A totipotent cell is one that can generate a
complete new organism
• Plant cloning is used extensively in agriculture
84. Figure 19.15
Cross
section of
carrot root
2-mg
fragments
Fragments were
cultured in nu-
trient medium;
stirring caused
single cells to
shear off into
the liquid.
Single cells
free in
suspension
began to
divide.
Embryonic
plant developed
from a cultured
single cell.
Plantlet was
cultured on
agar medium.
Later it was
planted in soil.
Adult
plant
85. Cloning Animals: Nuclear Transplantation
• In nuclear transplantation, the nucleus of an
unfertilized egg cell or zygote is replaced with the
nucleus of a differentiated cell
• Experiments with frog embryos have shown that a
transplanted nucleus can often support normal
development of the egg
• However, the older the donor nucleus, the lower
the percentage of normally developing tadpoles
86. Frog embryo Frog egg cell Frog tadpole
UV
Less differ-
entiated cell
Donor
nucleus
trans-
planted
Enucleated
egg cell
Fully differ-
entiated
(intestinal) cell
Donor
nucleus
trans-
planted
Egg with donor nucleus
activated to begin
development
Most develop
into tadpoles.
Most stop developing
before tadpole stage.
EXPERIMENT
RESULTS
Figure 19.16
87. Reproductive Cloning of Mammals
• In 1997, Scottish researchers announced the birth
of Dolly, a lamb cloned from an adult sheep by
nuclear transplantation from a differentiated
mammary cell
• Dolly’s premature death in 2003, as well as her
arthritis, led to speculation that her cells were not
as healthy as those of a normal sheep, possibly
reflecting incomplete reprogramming of the
original transplanted nucleus
89. 4
5
6
RESULTS
Grown in culture
Implanted in uterus
of a third sheep
Embryonic
development
Nucleus from
mammary cell
Early embryo
Surrogate
mother
Lamb (“Dolly”) genetically
identical to mammary cell donor
Figure 19.17b
90. • Since 1997, cloning has been demonstrated in
many mammals, including mice, cats, cows,
horses, mules, pigs, and dogs
• CC (for Carbon Copy) was the first cat cloned;
however, CC differed somewhat from her female
“parent”
• Cloned animals do not always look or behave
exactly the same
92. Faulty Gene Regulation in Cloned Animals
• In most nuclear transplantation studies, only a
small percentage of cloned embryos have
developed normally to birth, and many cloned
animals exhibit defects
• Many epigenetic changes, such as acetylation of
histones or methylation of DNA, must be reversed
in the nucleus from a donor animal in order for
genes to be expressed or repressed appropriately
for early stages of development
93. Stem Cells of Animals
• A stem cell is a relatively unspecialized cell that
can reproduce itself indefinitely and differentiate
into specialized cells of one or more types
• Stem cells isolated from early embryos at the
blastocyst stage are called embryonic stem (ES)
cells; these are able to differentiate into all cell
types
• The adult body also has stem cells, which replace
nonreproducing specialized cells
94. Figure 19.19
Stem cell
Cell division
Stem cell and Precursor cell
Fat cells or Bone
cells
or White
blood cells
95. Embryonic and Adult Stem Cells
• Many early embryos contain stem cells capable
of giving rise to differentiated embryonic cells of
any type
• In culture, these embryonic stem cells reproduce
indefinitely
• Depending on culture conditions, they can be
made to differentiate into a variety of specialized
cells
• Adult stem cells can generate multiple (but not all)
cell types and are used in the body to replace
nonreproducing cells as needed
97. • Embryonic stem (ES) cells are pluripotent,
capable of differentiating into many different
cell types
• The ultimate aim of research with stem cells
is to supply cells for the repair of damaged or
diseased organs
• ES cells present ethical and political issues
98. • Researchers can treat differentiated cells, and
reprogram them to act like ES cells
• Researchers used retroviruses to induce extra
copies of four stem cell master regulatory genes
to produce induced pluripotent stem (iPS) cells
• iPS cells can perform most of the functions of
ES cells
• iPS cells can be used as models for study of
certain diseases and potentially as replacement
cells for patients
Induced Pluripotent Stem (iPS) Cells
Nobel Prize in Physiology or Medicine, 2012
99. Figure 19.21
Stem cell Precursor cell
Experiment
Skin
fibroblast
cell
Four “stem cell” master regulator
genes were introduced, using
the retroviral cloning vector.
Induced pluripotent
stem (iPS) cell
Oct3/4
Sox2
c-Myc
Klf4
100.
101. Remove skin cells
from patient. 2
1
3
4
Reprogram skin cells
so the cells become
induced pluripotent
stem (iPS) cells.
Patient with
damaged heart
tissue or other
disease
Return cells to
patient, where
they can repair
damaged tissue.
Treat iPS cells so
that they differentiate
into a specific
cell type.
Impact: The Impact of Induced
Pluripotent Stem (iPS) Cells on
Regenerative Medicine
102. • Many fields benefit from DNA technology and
genetic engineering
Concept 19.4
The practical applications of DNA-based
biotechnology affect our lives in many ways
103. Medical Applications
• One benefit of DNA technology is identification of
human genes in which mutation plays a role in
genetic diseases
• Researchers use microarray assays or other tools
to identify genes turned on or off in particular
diseases
• The genes and their products are then potential
targets for prevention or therapy
104. Diagnosis and Treatment of Diseases
• Scientists can diagnose many human genetic
disorders using PCR and sequence-specific
primers, then sequencing the amplified product to
look for the disease-causing mutation
• SNPs may be associated with a disease-causing
mutation
• SNPs may also be correlated with increased risks
for conditions such as heart disease or certain
types of cancer
105. Human Gene Therapy
• Gene therapy is the alteration of an afflicted
individual’s genes
• Gene therapy holds great potential for treating
disorders traceable to a single defective gene
• Vectors are used for delivery of genes into
specific types of cells, for example bone marrow
• Gene therapy provokes both technical and ethical
questions
106. Figure 19.22
Cloned gene
2
1
3
4
Retrovirus
capsid
Bone
marrow
cell from
patient
Viral RNA
Bone
marrow
Insert RNA version of normal allele
into retrovirus.
Let retrovirus infect bone marrow cells
that have been removed from the
patient and cultured.
Viral DNA carrying the normal
allele inserts into chromosome.
Inject engineered
cells into patient.
107. Pharmaceutical Products
• Advances in DNA technology and genetic
research are important to the development of new
drugs to treat diseases
108. • The drug imatinib is a small molecule that inhibits
overexpression of a specific leukemia-causing
receptor
• Pharmaceutical products that are proteins can be
synthesized on a large scale
1. Synthesis of Small Molecules for Use as Drugs
109. • Host cells in culture can be engineered to secrete
a protein as it is made, simplifying the task of
purifying it
• This is useful for the production of insulin, human
growth hormones, and vaccines
2. Protein Production in Cell Cultures
110. • Transgenic animals are made by introducing
genes from one species into the genome of
another animal
• Transgenic animals are pharmaceutical “factories,”
producers of large amounts of otherwise rare
substances for medical use
3. Protein Production by “Pharm” Animals
112. Forensic Evidence and Genetic Profiles
• An individual’s unique DNA sequence, or genetic
profile, can be obtained by analysis of tissue or
body fluids
• DNA testing can identify individuals with a high
degree of certainty
• Genetic profiles can be analyzed using RFLP
analysis by Southern blotting
113. • Even more sensitive is the use of genetic markers
called short tandem repeats (STRs), which are
variations in the number of repeats of specific
DNA sequences
• PCR and gel electrophoresis are used to amplify
and then identify STRs of different lengths
• The probability that two people who are not
identical twins have the same STR markers is
exceptionally small
• As of 2013 more than 300 innocent people have
been released from prison as a result of STR
analysis of old DNA evidence
114. Figure 19.24
This photo shows
Washington just before
his release in 2001,
after 17 years in prison.
(a)
(b)These and other STR data exonerated Washington
and led Tinsley to plead guilty to the murder.
Semen on victim
Earl Washington
Kenneth Tinsley
17,19
16,18
17,19
13,16
14,15
13,16
12,12
11,12
12,12
Source of
sample
STR
marker 1
STR
marker 2
STR
marker 3
115. Environmental Cleanup
• Genetic engineering can be used to modify the
metabolism of microorganisms
• Some modified microorganisms can be used to
extract minerals from the environment or degrade
potentially toxic waste materials
116. Agricultural Applications
• DNA technology is being used to improve
agricultural productivity and food quality
• Genetic engineering of transgenic animals speeds
up the selective breeding process
• Beneficial genes can be transferred between
varieties of species
117. • Agricultural scientists have endowed a number of
crop plants with genes for desirable traits
• The Ti plasmid is the most commonly used vector
for introducing new genes into plant cells
• Genetic engineering in plants has been used to
transfer many useful genes including those for
herbicide resistance, increased resistance to pests,
increased resistance to salinity, and improved
nutritional value of crops
118. Plant with new trait
RESULTS
TECHNIQUE
Ti
plasmid
Site where
restriction
enzyme cuts
DNA with
the gene
of interest
Recombinant
Ti plasmid
T DNA
Agrobacterium tumefaciens
Research Method:
Using the Ti
Plasmid to Produce
Transgenic Plants
119. Safety and Ethical Questions Raised
by DNA Technology
• Potential benefits of genetic engineering must
be weighed against potential hazards of
creating harmful products or procedures
• Guidelines are in place in the United States
and other countries to ensure safe practices for
recombinant DNA technology
120. • Most public concern about possible hazards
centers on genetically modified (GM) organisms
used as food
• Some are concerned about the creation of “super
weeds” from the transfer of genes from GM crops
to their wild relatives
• Other worries include the possibility that
transgenic protein products might cause allergic
reactions
121. • As biotechnology continues to change, so does
its use in agriculture, industry, and medicine
• National agencies and international organizations
strive to set guidelines for safe and ethical
practices in the use of biotechnology