Question

Which of the following correctly summarizes the main issue with most genetically engineered food crops?
Answer

Creating a market for the resulting crops has proven difficult

Increasing one quality in a food crop may degrade other qualities

Resulting crops are too expensive because of the engineering

Resulting crops have to be continually monitored and re-engineered

Answer 1

i dont need the answer. i need to know how this happens

Answer 2

I'm sorry, do you mean how crops are engineered, or why they have to be continually monitored and re-engineered?

Answer 3

both

Answer 4

Genetically engineering anything involves either inserting new DNA or removing old DNA from a chromosome. This target DNA is almost always a gene or set of genes, but occasionally is a regulatory element like a promoter or enhancer instead. You would do well to read the Wiki on gene knock ins and gene knock outs, which are two commonly used procedures. You would also do well to read up on "site directed mutagenesis" where the existing sequence is modified but new DNA isn't directly inserted into the genome.

When new genes or DNA are inserted into a chromosome, they almost always come from an existing species. For example, one strain of corn might be drought resistant, so scientists would take that gene and modify other strains of corn by inserting it. That way the modified strains of corn would probably be drought resistant too.

Clear on that much before we move on to the second part?

Good answer to the circulatory/respiratory prob, by the way. :D

Answer 5

Thanks a lot this was really helpful and thanks haha :)

Answer 6

You're quite welcome! :d

The second part, why does a strain need to re-engineered quite often, is the more complicated question. The basic answer is loss of biodiversity.

The genetically engineered species have some trait - drought resistance, perhaps, or they taste bad to bugs or whatever - which means they will survive better than the non-engineered species. If they weren't better than the plants farmers already had, farmers wouldn't grow them. This means that after a few years, almost all the plants in a given population will all be genetically engineered. That is, all these genetically similar organisms will be living in densities the unmodified strains would never have achieved.

This is bad because if a bacteria or fungus or some other plant disease comes along which can attack the genetically engineered species, it will have a field day. All these genetically susceptible individuals living close so together! So whenever a pathogen comes along which can attack the genetically engineered crop, a new genetically engineered variant has to be made which is resistant to that particular pathogen.

Answer 7

wow this makes alot more sense now!

Answer 8

I am quite glad - that's what we're here for. ;P

Answer 9

i appreciate it