Chapter 4 Flashcards
(183 cards)
1
Q
Term/Front
A
Definition/Back
2
Q
What is an endonuclease?
A
An endonuclease is an enzyme responsible for cutting strands of DNA by cleaving the phosphodiester bond of the sugar-phosphate backbone.
3
Q
What are two important agricultural uses of GMOs?
A
Increased crop productivity and increased disease resistance of the crop.
4
Q
What are restriction endonucleases?
A
Restriction endonucleases are enzymes that target specific recognition sites on DNA to cut the strands, acting like molecular scissors.
5
Q
What is the first stage in producing transgenic plants?
A
Gene Identification: A specific gene with desirable characteristics is identified and isolated from another species’ genome.
6
Q
What is the process of cutting DNA by endonucleases called?
A
The process is referred to as ‘restriction endonuclease digestion’.
7
Q
How is the isolated gene introduced into the host organism?
A
Through direct insertion into the host organism’s genome or via a bacterial plasmid that transfers DNA.
8
Q
What happens during the Gene Expression stage?
A
The transformed cells are cultured and regenerated, allowing the GM host organism to express the new transgene as a functional protein.
9
Q
What is a recognition site?
A
A recognition site is a specific target sequence of DNA upon which restriction endonucleases act.
10
Q
What does genetic engineering technologies refer to?
A
The artificial alteration of an organism’s genome via the exchange of foreign genetic material, typically from another organism.
11
Q
What is the difference between sticky end and blunt end endonucleases?
A
Blunt end endonucleases cut DNA in the middle of the recognition site, resulting in a straight cut, while sticky end endonucleases create staggered cuts with overhanging nucleotides.
12
Q
Why are sticky end endonucleases advantageous in DNA manipulation?
A
Sticky end endonucleases ensure that an inserted gene is oriented correctly due to the attraction of unpaired nucleotides to complementary sets.
13
Q
What is a genetically modified organism (GMO)?
A
An organism with genetic material that has been altered using genetic engineering technology.
14
Q
What is a sticky end in DNA manipulation?
A
A sticky end is the result of a staggered cut through double-stranded DNA by an endonuclease, resulting in overhanging nucleotides.
15
Q
What is a transgenic organism?
A
A genetically modified organism that contains foreign genetic material from a separate species.
16
Q
What is plant tissue culture used for?
A
To grow plant cells, tissues, or organs under sterile conditions using a nutrient culture medium, widely used to produce clones of a plant.
17
Q
What is a blunt end in DNA manipulation?
A
A blunt end is the result of a straight cut across the double-stranded DNA by an endonuclease, resulting in no overhanging nucleotides.
18
Q
What are ligases and their function?
A
Ligases are enzymes that join two fragments of DNA or RNA together by catalyzing the formation of phosphodiester bonds.
19
Q
What is a transgene?
A
A gene that has been artificially introduced into the genome of a separate organism.
20
Q
What are the two main types of ligases?
A
The two main types of ligases are DNA ligase, which joins DNA fragments, and RNA ligase, which joins RNA fragments.
21
Q
What is a transgene?
A
A transgene is a gene that has been artificially introduced into the genome of a separate organism, usually of another species.
22
Q
How do GMOs contribute to increasing crop productivity?
A
GMOs enhance crop productivity by increasing crop yield per unit of farmland and improving crop quality, including nutritional value and resilience to environmental conditions.
23
Q
What is the role of polymerases in gene manipulation?
A
Polymerases add nucleotides to DNA or RNA, which can lead to copying entire genes.
24
Q
What is the projected global population by 2040?
A
The global human population is projected to reach approximately 9.2 billion by 2040.
25
What is a primer in the context of polymerase enzymes?
A primer is a short, single strand of nucleic acids that acts as a starting point for polymerase enzymes to attach.
26
What is the primary function of RNA polymerase?
RNA polymerase is primarily used in the transcription of genes.
27
Why are GMOs important in addressing food demand?
GMOs are important because conventional breeding methods may not suffice to meet the escalating demand for food driven by population growth and stagnant supply of grain and animal protein.
28
What role does DNA polymerase play?
DNA polymerase is used in the replication or amplification of DNA.
29
What is one application of GMOs in enhancing disease resistance?
GMOs can enhance crop resistance to diseases, improving global food security by reducing crop destruction and disease spread.
30
What percentage of crop yield losses are caused by plant pathogens and pests?
Crop yield losses caused by plant pathogens and pests are estimated at up to 30% globally.
31
What do polymerases require to attach to a template strand of DNA?
Polymerases require a primer to attach to the start of a template strand of DNA.
32
What are some concerns surrounding GMOs?
Concerns surrounding GMOs include their safety, naturalness, and various biological, social, and ethical implications.
33
What are primers in the context of DNA replication?
Primers are short single-stranded chains of nucleotides that are complementary to the template strand.
34
In which direction does polymerase synthesize a complementary strand?
Polymerase synthesizes a complementary strand in a 5' to 3' direction.
35
What is a significant threat posed by diseases like Asian soybean rust?
Diseases like Asian soybean rust can lead to catastrophic crop yield losses, reaching up to 90%, particularly threatening developing countries reliant on agriculture.
36
What is CRISPR and its role in bacteria?
CRISPR is a naturally occurring sequence of DNA in bacteria that serves as a primitive adaptive immune system, protecting them from viral attacks by storing viral genetic material and using it to target and destroy invading viruses.
37
What is a genetically modified organism (GMO)?
A GMO is any organism whose genetic material has been altered using genetic engineering technology.
38
How do bacteria use CRISPR-Cas9 to defend against viruses?
When a virus infects a bacterium, it inserts its genetic material. The bacterium stores a portion of this viral DNA as a 'mugshot' in its genome. Upon subsequent infections, it transcribes this mugshot and attaches it to the endonuclease Cas9, which then targets and destroys the virus.
39
What is a transgenic organism?
A transgenic organism is a type of GMO that contains foreign genetic material from a separate species or recombinant DNA from the same species that has been manipulated before introduction.
40
How are transgenic plants used in agriculture?
Transgenic plants are used to improve crop productivity and disease resistance, particularly in developing nations.
41
What are the components of the CRISPR system in bacterial genomes?
The CRISPR system consists of short, repeated sequences of nucleotides known as CRISPR, interspaced with spacer DNA that is derived from viral invaders, allowing for recognition during future infections.
42
When was the CRISPR-Cas9 system discovered?
The CRISPR-Cas9 system was discovered in 1987, although its potential applications were not recognized until many years later.
43
What are some implications of using GMOs?
The use of GMOs generates a range of ethical, biological, and social implications that lead to ongoing debate.
44
What is a virus?
A non-cellular, infectious agent composed of genetic material enclosed in a protein coat that requires a host cell to multiply.
45
What is a bacteriophage?
A virus that infects prokaryotic organisms.
46
What is CRISPR-Cas9?
A complex formed between gRNA and Cas9 which can cut a target sequence of DNA.
47
What is an endonuclease?
An enzyme that breaks the phosphodiester bond between two nucleotides in a polynucleotide chain.
48
What does CRISPR-associated protein 9 (Cas9) do?
It is an endonuclease that creates a blunt end cut at a site specified by guide RNA (gRNA).
49
What are CRISPR sequences?
Short, clustered repeats of DNA found in prokaryotes which protect them against viral invasion.
50
What is a spacer in the context of CRISPR?
Short sequences of DNA obtained from invading bacteriophages that are added into the CRISPR sequence.
51
How does the CRISPR-Cas9 defense system work during exposure?
Cas1 and Cas2 enzymes identify the viral DNA as foreign and cut out a short section, called a protospacer, which is integrated into the bacterium's CRISPR gene as a spacer.
52
What happens during the expression phase of the CRISPR-Cas9 system?
The CRISPR spacers are transcribed into guide RNA (gRNA), which binds to Cas9, forming a CRISPR-Cas9 complex that guides the complex to any complementary viral DNA inside the cell.
53
What does the CRISPR-Cas9 complex do when it finds matching bacteriophage DNA?
It cleaves the phosphate-sugar backbone of the viral DNA, effectively inactivating the virus.
54
What is a protospacer?
A short sequence of DNA extracted from a bacteriophage by Cas1 and Cas2, which has yet to be incorporated into the CRISPR gene.
55
What is the role of the protospacer adjacent motif (PAM)?
It is a sequence of two to six nucleotides found immediately next to the DNA targeted by Cas9.
56
What is guide RNA (gRNA)?
RNA with a specific sequence determined by CRISPR to guide Cas9 to a specific site.
57
What is a blunt end in DNA?
The result of a straight cut across the double-stranded DNA by an endonuclease, resulting in no overhanging nucleotides.
58
What happens to viral DNA after it is cut by Cas9?
Enzymes within the bacterium will act to repair it, which can lead to errors that result in mutations, rendering viral genes non-functional.
59
What is the primary function of the CRISPR-Cas9 system in genetic engineering?
The CRISPR-Cas9 system is used to edit genomes with great precision, allowing for the amendment of deleterious mutations or the introduction of biologically advantageous alleles.
60
What is synthetic sgRNA and its role in CRISPR-Cas9 gene editing?
Synthetic sgRNA is a single strand of RNA created in a lab that has a complementary spacer to the target DNA, guiding the Cas9 enzyme to cut at a specific site.
61
What are the steps involved in using CRISPR-Cas9 for gene editing?
1. Obtain Cas9 enzyme with target PAM sequence. 2. Mix Cas9 and sgRNA to create CRISPR-Cas9 complex. 3. Inject the mixture into a specific cell. 4. Cas9 finds target PAM and checks sgRNA alignment. 5. Cas9 cuts the DNA. 6. The cell attempts to repair the blunt end cut. 7. New nucleotides may be introduced during repair.
62
What is gene therapy and how does it relate to CRISPR-Cas9?
Gene therapy involves repairing genetic mutations by replacing a defective gene with a healthy one, and CRISPR-Cas9 offers a precise method for such modifications.
63
What is a gene knockout in the context of CRISPR-Cas9?
A gene knockout is a technique where scientists prevent the expression of a target gene to understand its function, which can be achieved using CRISPR-Cas9.
64
What is one major limitation of CRISPR-Cas9 technology in humans?
The success seen in animal studies, such as eliminating muscular dystrophy in mice, has not yet been replicated in humans.
65
What must scientists do to induce substitution mutations using CRISPR-Cas9?
They must introduce the desired nucleotide sequence into the cell and hope it is taken up by the DNA repair machinery.
66
Why is progress in CRISPR-Cas9 technology slow?
Progress is slow due to ethical implications and concerns regarding the sanctity of human life when altering embryos.
67
What legal restriction exists regarding genetically modified embryos?
It is currently illegal to implant genetically modified embryos into human females and allow them to develop and be born.
68
How does the bioethical concept of non-maleficence relate to CRISPR-Cas9?
It discourages causing harm, leading some individuals to oppose the law against gestating genetically modified embryos due to concerns about unforeseen negative consequences.
69
What is CRISPR-Cas9 technology used for in the context of genetic conditions?
CRISPR-Cas9 technology can be used to fix debilitating genetic conditions in embryos, potentially reducing pain and disadvantage for the child and parents.
70
What are some challenges in applying CRISPR-Cas9 technology to human genetics?
Challenges include technical limitations in inducing specific mutations and ethical concerns regarding genetic manipulation and societal inequalities.
71
What does the term 'gene knock-in' refer to?
Gene knock-in is a technique in gene editing where scientists substitute or add nucleotides in a gene.
72
What is an embryo in human development?
An embryo refers to the early stage of development in humans, specifically during the first eight weeks.
73
What is differentiation in the context of cell development?
Differentiation is the process in which cells develop specialized characteristics, transforming them from one cell type to another more specialized type.
74
What is the purpose of the polymerase chain reaction (PCR)?
The polymerase chain reaction amplifies a sample of DNA by creating additional copies, allowing for further analyses when there is an insufficient amount of DNA.
75
How does the polymerase chain reaction (PCR) work?
PCR is a multistep process that involves thermal cycling, where the amount of DNA present is doubled after each cycle.
76
What are some applications of PCR?
PCR is used for paternity testing, forensic testing of bodily fluids, and analyzing gene fragments for genetic diseases.
77
What role do primers play in PCR?
Primers are short, single strands of nucleic acids that act as starting points for polymerase enzymes to attach, allowing for the amplification of specific genes.
78
What is a restriction endonuclease?
A restriction endonuclease is an enzyme that acts like molecular scissors to cut nucleic acid strands at specific recognition sites, aiding in the efficiency of PCR.
79
What is the process of the polymerase chain reaction (PCR)?
The process of PCR involves manipulating temperatures to cause denaturation and annealing in a four-step process: Denaturation, Annealing, Elongation, and Repeat.
80
What materials are required for the polymerase chain reaction?
A DNA sample, Taq polymerase, nucleotide bases, and sequence-specific DNA primers are required for PCR.
81
What is the role of Taq polymerase in PCR?
Taq polymerase is a heat-resistant enzyme that binds to primers and synthesizes a new complementary strand of DNA during the elongation stage.
82
What happens during the denaturation step of PCR?
During denaturation, DNA is heated to approximately 90-95 °C to break the hydrogen bonds between the bases and separate the strands, forming single-stranded DNA.
83
What occurs during the annealing step of PCR?
In the annealing step, the single-stranded DNA is cooled to approximately 50-55 °C to allow the primers to bind to complementary sequences on the single-stranded DNA.
84
What is the purpose of the elongation step in PCR?
During elongation, the DNA is heated to 72 °C, allowing Taq polymerase to work optimally and synthesize a new complementary strand of DNA.
85
How many times is the PCR cycle repeated?
The PCR cycle (steps 1-3) is repeated multiple times to create more copies of DNA.
86
What is a thermal cycler?
A thermal cycler is a laboratory apparatus that alters the temperature in pre-programmed steps for temperature-sensitive reactions like PCR.
87
What does it mean to anneal in the context of PCR?
To anneal means to join two molecules, such as two complementary DNA strands, during the cooling phase of PCR.
88
What are the two different DNA primers needed in the polymerase chain reaction?
The two primers are the forward primer, which binds to the start codon at the 3’ end of the template strand, and the reverse primer, which binds to the stop codon at the 3’ end of the coding strand.
89
What is the function of the forward primer in PCR?
The forward primer binds to the 3’ end of the template strand and allows Taq polymerase to synthesize a new DNA strand in the same direction as RNA polymerase.
90
What is the role of the reverse primer in PCR?
The reverse primer binds to the 3’ end of the coding strand and allows Taq polymerase to synthesize a new DNA strand in the reverse direction to RNA polymerase.
91
Why are both forward and reverse primers necessary in PCR?
Both primers are necessary because the 5’ ends of the template and coding strands are different, and Taq polymerase only functions towards the 3’ end.
92
What are the main steps involved in the polymerase chain reaction?
The main steps are (1) denaturing the DNA, (2) annealing the primers, (3) elongating the new strands, and (4) repeating the process to make more copies.
93
What is the purpose of gel electrophoresis?
Gel electrophoresis is used to separate DNA fragments based on their size.
94
How are DNA samples prepared for gel electrophoresis?
DNA samples are placed in wells of the gel using a micropipette, along with a standard ladder of DNA fragments for size estimation.
95
What material is the gel made of in gel electrophoresis?
The gel is made of agarose, which is a sponge-like jelly filled with tiny pores.
96
What role does the buffer solution play in gel electrophoresis?
The buffer solution helps carry an electric current through the agarose gel.
97
Why does DNA move towards the positive electrode during gel electrophoresis?
DNA is negatively charged due to its phosphate backbone, so it is attracted to the positive electrode.
98
What happens to DNA fragments of different sizes during gel electrophoresis?
Smaller DNA fragments move faster and travel further through the gel than larger fragments.
99
How are DNA bands visualized after gel electrophoresis?
The gel is stained with a fluorescent dye, such as ethidium bromide, allowing the DNA bands to be visualized under ultraviolet (UV) light.
100
What are electrodes in gel electrophoresis?
Conductors of electricity that are attached to both ends of a gel allowing an electrical current to pass through it.
101
What does a band represent in gel electrophoresis?
A line seen in the gel that corresponds to a collection of DNA fragments of a specific size.
102
What is ethidium bromide used for in gel electrophoresis?
A fluorescent dye that binds to DNA fragments in a gel and allows them to be easily visualized under ultraviolet light.
103
What is a kilobase (kb)?
A unit of measurement that corresponds to one thousand nucleotides, may also be written as kbp.
104
How do DNA fragments separate in gel electrophoresis?
Long fragments of DNA collect in bands near the well, while shorter fragments form bands further from the well.
105
What does it mean if two individuals have bands at the same distance from the well?
It indicates that they share the same allele size.
106
What is the significance of interpreting gels in VCE Biology?
It is essential for determining the size of DNA fragments and understanding genotyping as a practical application.
107
What effect does buffer concentration have on DNA movement during gel electrophoresis?
The greater the concentration of ions in the buffer, the more electric current is conducted through the gel, causing DNA to move further down the lane.
108
How does the duration of electric current application affect DNA movement in gel electrophoresis?
The longer the electric current is applied, the further the DNA will travel
109
What are some applications of polymerase chain reaction (PCR) and gel electrophoresis?
They can be used for diagnosing genetic disorders and identifying suspects in forensic science.
110
What is genetic testing?
Genetic testing involves screening an individual’s DNA for anomalies that may make them susceptible to a particular disease or disorder.
111
What is DNA profiling?
DNA profiling is the process of identification based on an individual’s genetic information.
112
How is cystic fibrosis diagnosed using gel electrophoresis?
A heel prick test at birth extracts genetic material, and PCR amplifies the CFTR gene mutation, which is then analyzed using gel electrophoresis.
113
What genetic pattern does cystic fibrosis follow?
Cystic fibrosis manifests when both alleles are mutated, highlighting its recessive inheritance pattern.
114
What is the approximate length of the isolated healthy CFTR gene as inferred from Figure 5?
Approximately 40 bp.
115
What does it mean if an individual is heterozygous in the context of cystic fibrosis?
They have DNA that aligns with both the healthy and mutated allele, meaning they would not suffer from cystic fibrosis as it is a homozygous recessive disorder.
116
How has DNA technology changed forensic analysis in modern crime investigations?
It allows for the extraction and amplification of minute DNA traces from crime scenes using the polymerase chain reaction (PCR).
117
What are short tandem repeats (STRs)?
They are repeated nucleotide sequences found in non-coding regions of autosomal chromosomes that vary in length between individuals.
118
Why are STRs used in DNA profiling?
Matching STR profiles between DNA samples indicates they originate from the same person, providing a reliable method for identifying suspects.
119
What is one common method for constructing a DNA profile?
Gel electrophoresis, where PCR is performed to amplify DNA and then a gel is run focusing on particular STRs.
120
What do heterozygous and homozygous individuals display on a gel during DNA profiling?
Heterozygous individuals display two bands, while homozygous individuals show a single, thicker band.
121
What does gel electrophoresis allow scientists to determine about DNA samples?
It allows scientists to determine how many different sizes of DNA fragments are in a sample and the size of each fragment.
122
How does gel electrophoresis separate DNA fragments?
Gel electrophoresis uses electricity to separate pieces of DNA based on size.
123
What is indicated by two bands on a gel in gel electrophoresis?
Two bands on the gel indicate heterozygous individuals, while homozygous individuals show a single, thicker band.
124
What is the significance of genetically modifying bacteria in modern medicine and agriculture?
Genetically modifying bacteria to produce human proteins has revolutionized modern medicine and agriculture by enabling cheaper and more efficient methods of production.
125
What are plasmids?
Plasmids are small, circular loops of DNA separate from the chromosome, typically found in bacteria, that replicate independently.
126
What is a recombinant plasmid?
A recombinant plasmid is a plasmid that has been edited to integrate a target gene of interest.
127
What process allows bacteria to take up recombinant plasmids from the environment?
The process is called bacterial transformation.
128
How do genetic engineers introduce foreign DNA into bacteria?
Genetic engineers insert foreign DNA into a plasmid, which can then be taken up by bacteria, allowing them to express the protein.
129
Why are plasmids considered excellent cloning vectors?
Plasmids can self-replicate, are small, can be taken up by bacteria, and allow for the inclusion of antibiotic resistance genes, recognition sites, and expression signals.
130
What is the gene of interest in recombinant plasmid creation?
The gene of interest is a specific DNA sequence that encodes a protein, isolated from its source organism and amplified, which is then inserted into a vector.
131
Why must the gene of interest lack introns before insertion into bacteria?
Bacterial gene expression does not involve RNA processing like in eukaryotes, so bacteria would not recognize or process introns.
132
What are the two major methods to exclude introns from the gene of interest?
1. Use Synthetic DNA, where genes are made in a lab without introns. 2. Use copy DNA (cDNA), made from mRNA using reverse transcriptase, which also lacks introns.
133
What are the four important DNA sequences most plasmids contain?
1. Restriction endonuclease sites, 2. Antibiotic resistance genes, 3. Origin of replication (ORI), 4. Reporter gene.
134
What must a plasmid contain to be selected for gene manipulation?
A plasmid must contain two genes that encode for observable traits, such as antibiotic resistance genes or reporter genes.
135
How are sticky ends generated for the gene of interest and plasmid?
The gene of interest and the plasmid are both cut with the same restriction endonuclease to generate identical sticky ends on either end of the DNA sequence.
136
What is the role of DNA ligase in the process of creating recombinant plasmids?
DNA ligase is added to join the gene of interest to the plasmid vector by forming phosphodiester bonds in the sugar-phosphate backbone, creating a circular piece of DNA called a recombinant plasmid.
137
What distinguishes a recombinant plasmid from a non-recombinant plasmid?
The role of the reporter gene is to distinguish between a recombinant and non-recombinant plasmid.
138
What process allows bacteria to take up free-floating DNA from their environment?
Many bacteria naturally take up free-floating DNA from their environment into their cytosol via transformation.
139
What is the process called that involves the insertion of recombinant plasmids into the cytoplasm of bacteria?
Bacterial transformation.
140
What are the two primary methods used to promote the uptake of recombinant plasmids?
Heat shock and electroporation.
141
How does the heat shock method increase the permeability of the bacterial plasma membrane?
By placing bacteria and plasmids in a calcium ion solution on ice, then heating to 37-42°C for 25-45 seconds, followed by returning to ice.
142
What is the role of calcium ions in the heat shock method?
They help make the plasma membrane more permeable to the negatively charged plasmid DNA.
143
What happens during electroporation?
An electric current is passed through a solution containing bacteria and plasmid vectors, increasing the permeability of the plasma membrane.
144
How can transformed bacteria be differentiated from untransformed bacteria?
By culturing a mixture on an antibiotic-rich plate
145
What is the purpose of using a reporter gene in plasmid vectors?
To distinguish between recombinant and non-recombinant plasmids based on fluorescence under UV light.
146
What indicates the presence of a recombinant plasmid in transformed bacteria?
The reporter gene is split by the gene of interest insertion, preventing fluorescence under UV light.
147
What happens to transformed bacteria with non-recombinant plasmids under UV light?
They fluoresce green due to continuous reporter genes.
148
What is the process of producing insulin using transformed bacteria?
Transformed bacteria are cultured and induced to produce the target protein, which is then extracted and purified.
149
Why is insulin crucial for individuals with diabetes?
Insulin is vital for regulating blood glucose levels in individuals who lack natural insulin production or response.
150
What was the traditional source of insulin before gene cloning techniques?
Insulin was sourced from animals such as pigs or cows, which was less effective and required extraction from animal pancreases.
151
What breakthrough occurred in the late 1970s regarding insulin production?
Human insulin began to be produced in bacteria containing recombinant plasmids, becoming the preferred method due to cost-effectiveness and superior efficacy.
152
What is the quaternary structure of insulin composed of?
Insulin consists of two polypeptide chains known as the alpha and beta subunits.
153
How are the two insulin subunits produced in transformed bacteria?
Two different recombinant plasmids are required, one for each subunit, with one bacteria producing the alpha subunit and the other producing the beta subunit.
154
What role do disulphide bridges play in insulin function?
Disulphide bridges join the individually folded alpha and beta chains together for insulin to function properly in the human body.
155
What genes were included in the plasmid vectors for insulin production?
The plasmid vectors contained genes for antibiotic resistance to ampicillin (ampR) and tetracycline (tetR).
156
Which restriction endonucleases were used to cut the insulin genes?
The insulin genes were cut by restriction endonucleases EcoRI and BamHI to form complementary sticky ends.
157
What are the roles of EcoRI and BamHI in gene manipulation?
EcoRI and BamHI are restriction endonucleases that cut genes to form complementary sticky ends.
158
What is the purpose of DNA ligase in the creation of recombinant plasmids?
DNA ligase is used to re-establish the sugar-phosphate backbone, resulting in distinct recombinant plasmids.
159
How can bacteria with recombinant plasmids be identified?
Bacteria are spread on agar plates with ampicillin and tetracycline
160
What is the significance of the LacZ gene in the recombinant plasmids?
The LacZ gene codes for ß-galactosidase, which helps create fusion proteins with insulin subunits, protecting them from E. coli digestive enzymes.
161
How are bacteria with LacZ-containing plasmids identified?
They are identified by their ability to turn blue when plated on agar with X-gal and ampicillin, indicating ß-galactosidase presence.
162
What process is used to extract fusion proteins from transformed bacteria?
Transformed bacteria are induced to multiply and then lysed to extract fusion proteins.
163
What is the role of cyanogen bromide in the protein production process?
Cyanogen bromide is used to cleave the added methionine, separating insulin subunits from ß-galactosidase.
164
How is functional human insulin produced from the two insulin chains?
The two insulin chains are mixed, allowing disulphide bonds to form, resulting in functional human insulin.
165
What is the process of bacterial transformation?
Bacterial transformation occurs through the extraction of target genes, formation of recombinant plasmids, and plasmid uptake by bacteria.
166
How can transformed bacteria be distinguished from non-transformed bacteria?
Transformed bacteria can be distinguished by including an antibiotic resistance gene in the plasmid vector, which is expressed solely by the successfully transformed bacteria.
167
What can be done with the proteins produced by transformed bacteria?
The proteins produced by transformed bacteria, such as human insulin, can be purified.
168
What is the primary objective of genetic engineering in GMOs?
The primary objective is usually to impart desirable traits absent from the host's original genome.
169
What are genetically modified organisms (GMOs)?
Organisms modified through genetic engineering techniques, which may involve inserting, removing, or altering genes.
170
What distinguishes transgenic organisms from cisgenic organisms?
Transgenic organisms have genes from a different species inserted into their genome, while cisgenic organisms have genes from the same species.
171
What is cisgenesis?
Cisgenesis is the process of transferring genes between organisms of the same species.
172
What is transgenesis?
Transgenesis is the process of inserting genes from a different species into an organism's genome.
173
What can transgenic organisms produce that was not previously part of their species' proteome?
Transgenic organisms can produce proteins that were not previously part of their species' proteome due to the insertion of foreign DNA.
174
What are two important agricultural uses of GMOs?
Increased crop productivity and increased disease resistance of the crop.
175
What is the first stage in producing transgenic plants?
Gene Identification: A specific gene with desirable characteristics is identified and isolated from another species' genome.
176
How is the isolated gene introduced into the host organism?
Through direct insertion into the host organism's genome or via a bacterial plasmid that transfers DNA.
177
What happens during the gene expression stage?
The transformed cells are cultured and regenerated, allowing the GM host organism to express the new transgene as a functional protein.
178
What is a genetically modified organism (GMO)?
An organism with genetic material that has been altered using genetic engineering technology.
179
What are cisgenic organisms?
Genetically modified organisms that contain foreign genetic material from a sexually compatible donor organism, typically from the same species.
180
What is a transgenic organism?
A genetically modified organism that contains foreign genetic material from a separate species.
181
What is plant tissue culture?
A range of techniques used to grow plant cells, tissues, or organs under sterile conditions using a nutrient culture medium.
182
What is a transgene?
A gene that has been artificially introduced into the genome of a separate organism.
183
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