COPY: COPY: DNA Fingerprinting and Gel Electrophoresis

Podcast

Play an AI-generated podcast conversation about this lesson

Download our mobile app to listen on the go

Get App

Questions and Answers

Explain how gel electrophoresis separates DNA fragments and why this separation is important in forensic DNA analysis.

Gel electrophoresis separates DNA fragments by size using an electric field. Smaller fragments move faster through the gel than larger ones. This separation is crucial in forensic analysis because it allows for the comparison of DNA fragment patterns from different samples, such as crime scene evidence and suspect DNA.

Describe the role of restriction enzymes in preparing DNA for gel electrophoresis in forensic analysis.

Restriction enzymes cut DNA into fragments at specific sequences. In forensic analysis, they are used to create DNA fragments containing genes and repeats of varying lengths, which can then be separated and compared using gel electrophoresis.

Explain why polymerase chain reaction (PCR) is often necessary before performing gel electrophoresis on DNA samples from a crime scene.

PCR amplifies (copies) specific DNA sequences. This is crucial when the initial DNA sample is small, as it provides a sufficient amount of DNA to produce a clearly visible result after gel electrophoresis.

What are short tandem repeats (STRs), and why are they useful in DNA fingerprinting for personal identification?

STRs are short, repeating sequences of DNA that vary in the number of repeats between individuals. This variation makes them unique identifiers for DNA fingerprinting, allowing for accurate personal identification. Signup and view all the answers

A DNA sample from a crime scene shows a specific STR with 12 repeats. A suspect's DNA shows the same STR with 9 repeats. Could this suspect be the source of the crime scene DNA? Explain.

No, the suspect is likely not the source. If the STR lengths don't match (12 repeats at the crime scene vs. 9 repeats in the suspect), it indicates that the DNA samples are from different individuals. Signup and view all the answers

Explain how genetic testing can identify individuals who carry a recessive trait for a disease like cystic fibrosis, even if they don't have the disease themselves.

Genetic testing can identify carriers of recessive traits by detecting the presence of one copy of the disease-causing gene. Carriers do not show symptoms because they also have a normal copy of the gene, but they can pass the trait on to their offspring. Signup and view all the answers

In the context of prenatal diagnosis, what is the purpose of performing blood tests and ultrasounds on a fetus during pregnancy?

Blood tests and ultrasounds during prenatal diagnosis are used to detect chromosomal abnormalities in the fetus, such as Down syndrome. This information helps parents prepare for the child's needs or make decisions regarding the pregnancy. Signup and view all the answers

Describe the process of preimplantation genetic diagnosis (PGD) and explain its ethical implications.

PGD involves testing embryos created through in vitro fertilization for genetic disorders before implantation. Healthy embryos are then selected for implantation. Ethically, it raises questions about selecting against certain traits and the potential for 'designer babies'. Signup and view all the answers

Why do some critics argue that at-home genetic tests should only be conducted under the supervision of healthcare providers?

Critics argue that healthcare providers can provide professional help in interpreting the results correctly, helping prevent unnecessary anxiety or a false sense of security. They can also ensure appropriate follow-up care and counseling. Signup and view all the answers

Explain how genetic modification differs from traditional animal breeding techniques.

Genetic modification involves directly altering an organism's genetic material, allowing for changes beyond what's possible through random mutations in traditional breeding. It enables the introduction of foreign DNA and targeted gene modifications. Signup and view all the answers

Describe the process of genetically modifying bacteria to produce human insulin. Be sure to include how the insulin is later harvested.

A plasmid is removed from a bacterium and cut open using an enzyme. The human insulin gene is inserted into the plasmid, which is then transferred back into the bacterium. The bacteria is cultured in a bioreactor, and the insulin is extracted and purified for use. Signup and view all the answers

What are some advantages of using genetically modified bacteria (GMB) to produce medicines like human growth hormone, compared to previous methods?

GMB allows for large-scale production of medicines with minimal risk of contamination or infection. It is also more efficient and less cumbersome compared to extracting hormones from deceased individuals, as was done previously. Signup and view all the answers

Explain two methods used to genetically modify animals.

One method involves injecting foreign DNA into the nucleus of a fertilized egg. Another method uses CRISPR/Cas9 to make targeted mutations to inactivate or replace a specific gene in the animal's DNA. Signup and view all the answers

What are knockout mice, and why are they valuable in medical research?

Knockout mice are genetically modified mice in which a specific gene has been deactivated or 'knocked out'. They are valuable in medical research because researchers can study the function of the deactivated gene and how its absence affects the development of various diseases. Signup and view all the answers

Describe one potential environmental concern associated with genetically modified salmon, and how scientists are trying to address this concern.

A potential concern is that if GM salmon escape and reproduce with wild salmon, it could alter the genetic makeup of wild populations. To address this, many GM salmon are made sterile to prevent reproduction. Signup and view all the answers

Explain two ways in which genetically modified (GM) crops can be beneficial to agriculture.

GM crops can provide greater yields due to herbicide tolerance (allowing for effective weed control) and insect resistance. This can result in more efficient land use and reduced losses from pests. Signup and view all the answers

What is herbicide tolerance in GM crops, and what are some potential drawbacks associated with its use?

Herbicide tolerance is when crops are modified to withstand specific herbicides, allowing farmers to spray fields without harming the crops. A drawback is the increased use of herbicides, which can lead to herbicide leakage into groundwater and surrounding environments, posing risks to human health and biodiversity. Signup and view all the answers

Describe the potential economic concerns associated with genetically modified crops related to seed saving and patents.

Because companies often have patents on GM crops, farmers may be unable to save seeds from their harvest for replanting and must purchase new seeds each year. This can lead to debt if the harvest fails and shift power from farmers to large corporations. Signup and view all the answers

What is the basic principle behind gene therapy, and what is its ultimate goal?

Gene therapy aims to replace defective genes with functioning copies to prevent or cure genetic diseases. The goal is to correct the underlying genetic cause of the disease, improving or restoring normal function. Signup and view all the answers

What were some of the challenges and setbacks faced in the early attempts at gene therapy during the 1990s and 2000s?

Early attempts at gene therapy faced challenges such as not knowing exactly where the gene ended up and the death of a young patient. Later attempts, while successful in curing immune deficiencies, led to some patients developing leukemia. Signup and view all the answers

Explain how the CRISPR/Cas9 gene scissors work to edit DNA sequences.

The Cas9 enzyme is guided to a specific DNA sequence by a piece of RNA. The Cas9 enzyme then cuts the DNA at that location. A new gene can then be inserted, and the DNA strands are linked together. Signup and view all the answers

What is the significance of using CRISPR/Cas9 gene editing on gametes or fertilized eggs, compared to gene therapy on somatic cells?

Changes made to gametes or fertilized eggs are heritable, meaning they will be passed on to future generations. Changes made to somatic cells are not heritable, affecting only the individual being treated. Signup and view all the answers

Describe some of the potential ethical concerns associated with using CRISPR/Cas9 gene editing on humans, especially regarding the definition of 'disease' and 'health'.

Ethical concerns include defining what constitutes a 'serious disease' versus a less serious condition, and whether gene editing should be used for enhancement purposes beyond treating diseases. Differing cultural values may also influence what is considered 'healthy' or 'sick'. Signup and view all the answers

Explain the concept of the 'slippery slope' argument in the context of CRISPR/Cas9 gene editing, particularly in relation to designing offspring.

The 'slippery slope' argument suggests that if gene editing is used to cure serious diseases, it could lead to its use for less serious conditions, and eventually for selecting for desirable traits in offspring, potentially leading to 'designer babies'. Signup and view all the answers

Explain why it is hard to tell by just looking at an organism whether it has been genetically modified or not.

Because only certain characteristics controlled by DNA affect appearance, it is not always possible to tell by looking at an organism whether it is genetically modified or not. Signup and view all the answers

Describe two use cases for genetically modified bacteria (GMB) besides the generation of insulin.

Besides insulin, GMB can also be used to produce other medicines, such as a medicine for haemophilia, treatment of cancer and human growth hormone. Signup and view all the answers

Explain what would be the significance of succeeding in changing the nitrogen base in all the body's cells back when a disease such as sickle cell anemia occurs, where the nitrogen base A is replaced by T.

If we were to succeed in changing the nitrogen base in all the body's cells back, the person would be cured of the disease. Signup and view all the answers

Explain how companies look to assess the risk of diseases when customers use at-home genetic testing services.

Companies look for gene variants that researchers have identified as risk genes for some common multifactorial diseases. Multifactorial diseases are caused by external environmental factors in cooperation with several different genes (cardiovascular diseases, age related diabetes and alzheimers. Signup and view all the answers

Explain why gene copies from other fish species have been inserted into the salmons DNA in order to increase the growth rate.

Gene copies from other fish species have been inserted into the salmons DNA in order to increase the growth rate. The main benefit is that this provides a more environmentally friendly and economical alternative to conventionally farmed salmon because it uses a smaller amount of feed per kilogram of fish produced as it grows faster. Signup and view all the answers

Name at least two good and two bad things when it comes to GM crops.

Two good things are greater yields and more efficient land use and that they do not have a bad impact on a person's health. Two bad things are increased use of herbicides when growing HT crops such as leakage from fields into the groundwater or into the surrounding environment and the risk of ecological damage such as genetically modified plants transferring their genes to wild plants. Signup and view all the answers

If one person only has one trait for a genetic disease what happens?

If one person only has one trait they do not get affected by the disease but can still pass the trait on. Signup and view all the answers

Where are GM crops mainly grown at in the world?

GM crops are mainly grown in China, US, Canada, Mexico and Argentina. Signup and view all the answers

Explain what is meant by insect resistance in GM crops.

Insect resistance means that a crop receives a gene from bacteria that causes the plant itself to produce an insecticide. Signup and view all the answers

Due to companies having patents on the crops, farmers can no longer save part of the harvest each year as seed. What can this lead to?

If farmers take loans to buy seeds for new crops they can fall into debt if the harvest fails. Signup and view all the answers

What are the risks of ecological damage regarding genetically modified plants?

The risk of ecological damage are that genetically modified plants will transfer their genes to wild plants and what the ecological damage would be in that case, such as superweed Signup and view all the answers

Describe what is meant by molecular biology.

Molecular biology has used DNA fingerprinting for use in identifying individuals and the personal identification. Signup and view all the answers

Explain why insulin produced by transgenic bacteria is beneficial.

Insulin produced by transgenic bacteria is beneficial because previous diabetics had been allowed to use insulin extracted from pigs or cattle leading to problems such as allergic reactions. Signup and view all the answers

Explain what benefits that GMA has to offer - why are they used in the food industry.

GMA are rarely used in the food industry except salmon which has been allowed to be sold in Canada since 2016. More environmentally friendly and economical alternative to conventionally farmed salmon because it uses a smaller amount of feed per kilogram of fish produced as it grows faster. Signup and view all the answers

What is needed when scientists have acquired DNA from a human being and want to perform gel electrophoresis on the DNA?

What they do is that they take a small sample and copy a specific DNA sequence using polymerase chain reaction. If not used the gel will appear blank due to the DNA being an insufficient amount to produce a clearly visible result. Signup and view all the answers

What does securing biological traces potentially lead to?

DNA becomes useful for forensic investigations → securing biological traces → National Forensic Center → copied and analysed → compared with DNA profiles of suspects. Signup and view all the answers

Explain what ethical concerns comes with PGD - Preimplantation Genetic Diagnosis, what can happen if it is misused

Risk for us “designing our children”. Danger that a selection of characteristics is not compatible with the fundamental idea of a democratic society that all people have equal value. Risk that tolerance towards people with certain undesirable characteristics or diseases would decrease in society Signup and view all the answers

In what way can genes be moved between different species when creating genetic modification?

Genetic modification can happen due to all organisms having a genetic code where DNA and mRNA are translated into amino acids. Due to this genes can also be moved between different species. Signup and view all the answers

Flashcards

Gel Electrophoresis

Separates DNA fragments by size using an electric field. Smaller fragments move faster.

Restriction Enzymes

Cut DNA into fragments at specific sequences for comparison.