Unit 3: AOS 1 error log

Endonucleases are _ _?

restriction enzymes

What do word do you use call smaller and bigger fragments of DNA?

shorter and longer

What could you mention when analysing a gel electrophoresis?

mention fragment length,

What effects the rate of DNA fragment movement through agarose gel?

concentration/viscosity of agarose gel, size/length of DNA fragments, voltage/power used

What safety precautions should be followed when using gel electrophoresis?

ensure the gel electrophoresis is turned off to prevent electrocution, wear safety glasses to protect the eye, dispose of materials correctly, wear gloves to prevent contamination by DNA or the chemicals being used

What are some examples of disorders or diseases that can be detected by genetic screening?

down syndrome, sickle cell anaemia, albinism, PKU, cystic fibrosis

What enzyme synthesises new DNA strands in PCR?

Taq polymerase because it can withstand the temps

How should you write an ethical implication in a question?

ask it in question form as it is clearer

How to think of a social implication in question?

check whether your answer relates to society and impacts more than one or two individuals

What is a recombinant plasmid?

a plasmid with foreign DNA

Advantages for an organism to be able to turn genes on or off?

control biochemical pathways within the cell, only produce products when required by the cell, different cells require different proteins (e.g. eye cell does not require hormones), conserve ATP for other cellular processes

Do both attenuation and repression occur when trp levels are low?

repression doesn’t happen when trp are low, so they have in common that they happen when they are high. so in a question where it says to compare, only mention the high parts

What enzyme inserts genes in a plasmid?

DNA ligase

How can you determine if two individuals could be the parents of a child using STR data?

1. Each person inherits one STR allele from each parent at every STR marker.

2. For each STR:

   • The child’s two numbers (alleles) must match one number from each parent.

3. Repeat this check for all STRs provided.

4. If every STR in the child can be explained by combining one allele from each parent, they could be the biological parents.

Why would concentrations of different types of proteins change?

Enzyme: If there is a change in substrate concentration, then more or less enzyme may be produced to conserve ATP

OR

Structural protein: repair or synthesis of organelles if organelles are damaged due to increased or decreased temperature

OR

Regulatory/repressor protein: more or less repressor protein is required to inhibit or promote a reaction when there is a change in substrate availability

OR

Transcription factors: more or less is required for transcription if environmental conditions result in increased or decreased need for protein synthesis.

What does a justify question require you to say?

say why my answer is correct AND incorrect

potential benefits of using the CRISPR technique to edit

genes in the future

• improve IVF pregnancy rates

• eliminate deadly genetic diseases before people are born

• can help treat genetic diseases by fixing mutated genes

Potential concerns of using CRISPR technique to edit genes in the future

• making changes to human DNA could create an error to the human gene pool that introduces disease that could be passed on to future generations

• making incorrect DNA edits

• creating genetically modified babies for desired traits

• using viable embryos for research which are then destroyed

Explain the role played by primers and why you need two

• primers will bind to a complementary DNA sequence on the target gene

• it allows taq polymerase to bind to the target gene and amplify the target DNA

• as one strand runs 3’ to 5’ and the other runs 5’ to 3’, you need two primers to amplify both DNA strands as the DNA sequences will be different at each end.

Describe how restriction enzymes such as BamHI are used to help insert a gene coding for a human protein into this plasmid.

the same restriction enzyme (BAM H1 in this case) cuts the gene of intereest and plasmid at a specific sequence of base pairs. this creates sticky ends, allowing the gene to be inserted to the plasmid according to complementary base pairing rules

Explain how scientists use antibiotics to identify which of the bacterial cells have been successfully transformed with plasmids carrying the human gene

• grow the bacteria on agar containing ampicillin

• bacteria that grow on agar containing ampicillin have taken up the plasmid with the human gene Amp^r

• bacteria that have not taken up the plasmid are killed by ampicillin

What does "gene structure" refer to in the context of comparing genes like RbcL and RbcS?

the features of a gene at the DNA level, including the presence of:

• promoter (slight different in bp length) regions so RNA polymerase can bind

• operator regions(where repressor protein binds)

• introns and exons (in eukaryotic genes)(difference between nucelotide sequence size andd mRNA sequence size, that means introns are cut out)

• terminator sequences (difference between nucleotide sequence and mRNA sequence)

It describes how a gene is organised, rather than the amino acid sequence or protein size it codes for. Slight difference in nucleotide sequence and mRNA sequence

What does DNA ligase do?

it joins phophodiester bonds between the sugar and phosphate of nucleotides/between the gene of interest and the original gene

what makes an organism genetically modified?

the DNA has bee altered using gene technology

different ways you can improve crops

• improve the yield to produce more

• additional nutritional value

• herbicide/pesticide resistance

• drought tolerance

• disease resistance

Using a consequence based approach, discuss whether the use of genetically modified or transgenic plants would be considered as bioethical.

• The action that leads to the best overall outcome to the most people (minimising negative effects) regardless of whether the act is right or wrong

• If GM technology is used it is possible to create crops that could help populations that are vitamin deficient/produce high yields/grow better in their environment

• if GM technology is not used then farmers will have to use selective breeding which could take a long amount of time to see the same phenotype

• Therefore using gene technology is ethical

what does restriction enzyme do

cuts gene of interest and plasmid at specific restriction site

reminder: be specific for the question

ok

what is beneficience?

Aiming to improve others lives through charity, generosity and kindness (any two of these).

what is non-maleficence?

avoiding actions that cause harm

what is a transgenic organism?

GM organism that has received DNA from another species

how to answer explain question?

blablabla SO blabla

referencing molecular level of the GM crop

• new gene and therefore new DNA

• gene is transcribed and translated

• therefore a new protein is expressed

how to answer question referring to consequence based approach

• outcomes of option A and option B are compared to determine which will have the best overall benefits regardless of what the action is

• if they do option A these postive benefits will happen

• if they do option B farmers will have to rely on what is normal so these bad things may occur/not occur

• the most ethical approach would be the one that provides the most benefits (say how)

Describe the possible changes the scientists can make to a gene, when using CRISPR-Cas9 technology.

• insert a nucleotide

• delete a gene

• insert stop codon to create a shortened protein

Discuss possible known consequences of editing a genome

• · Could cause a mutation in the gene and result in an altered/non functional protein

• · Off target mutations (causing a mutation somewhere else in the genome)

• · insertional oncogenesis to viral vector

• · Immunological reaction to vector delivering Cas9

• · Apoptosis of target cell occurs

what does PCR stand for?

polymerase chain reaction

why does denaturation need to be 95 degrees?

so that the hydrogen bonds between nucleotides can break, allowing the DNA strand to separate

What is the difference between a gene of interest and a target gene?

gene of interest: selected for study, isolation, or modification, used in genetic engineering or transformation.

target gene: the specific gene sequence that a technique like PCR or CRISPR is designed to act on.