What does linking biological ideas of Transgenesis look like?

I’m about to hand in my genetic transfer report, but I’m not sure if I’ve linked the biological ideas of selective breeding and transgenesis to the biological implications? It’s the excellence part of the marking schedule, but I’m not really sure what doing this looks like. What exactly are the ‘biological ideas’ and how do I link them? It sounds really vague lol

Hi hebeellen

I would have to cover some key points first before jumping to the “linking ideas” for E.

This standard requires you to describe and explain the complete process for:
-Selective breeding
(Two genetic manipulations)
For each of those manipulations, you need to discuss at least two biological implications.
Here’s the list of possible selection:

  • genetic biodiversity
  • health or survival of individuals
  • survival of populations
  • evolution of populations.

Link to standard:

Explanatory Notes 2 and 3 point these out.

Key points:

  1. Be sure to go over the (HOW of) the complete process for each manipulation.

For example for selective breeding, aim to cover things such as genomic selection, marker assisted selection, pcr, DNA sequencing, use of quantitative trait loci (QTL), and/or the selection of an appropriate (molecular) marker to select for the desirable traits/phenotypes.

For example, for transgenesis, explaining a logical sequence to the entirety of the process, such as the creation of a recombinant plasmid (with a marker, tissue-specific promoter sequence, the terminator sequence, and the desirable gene(s)), followed up by an insertion method of the plasmid into germ line cells (gametes), such as retrovirus-mediated gene transfer or embryonic stem cell-mediated gene transfer.
It is important to note that the method varies between creating a transgenic plant or animal. It is often easier to create a transgenic plant as you can use the Ti-plasmid and tissue culture, then check for the cells that have received the transgene using an antibiotic marker (that has been inserted into the recombinant plasmid)

The implications section will depend on which plant/animal you have used as a context for genetic manipulations.

For example, if you have chosen selectively bred cattle (any type of breed in general), explaining the wider implications to the ecosystem, such as linking the downstream effects of cattle farming to increased pollution in local waterways and potential loss of diversity in native aquatic species.

For transgenesis, there is a transgenic salmon that has been created known as AquaAdvantage Salmon. You could explain the wider implications to the ecosystem, such as linking the reduction in cost of farming AquAdvantage Salmon, which reduces the commercial fishing pressure on wild fish, thus helping to increase wild fish populations.

Students will often be able to link genetic biodiversity, survival of populations and evolution quite easily to the “case study” species, because, more often than not, when you have created the the genetically modified animal/plant breed, it will be mass produced. Hence you end up with a (monoclonal) population of that particular breed/cultivar (a different variety of that species).
This in turn would reduce the genetic variation within that population and thus with low genetic biodiversity, that particular breed/cultivar will be at risk to a changing environment (say a disease/viral infection). This point can also be linked to the fact that they will not have an opportunity to evolve (change in the allele frequency of a population over time) because the farmers etc would be continually selecting for those desirable alleles/genes in that population.

To get an E, you need to ensure that both genetic manipulation processes have been discussed up to E, and 2 implications for each of those manipulations have been covered.
Where the implications are similar (such as genetic biodiversity, evolution and survival) you can combine them together and it can count a point for both manipulations.

Hope that helps!

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