Why must use the same sequence in the same gene if you're comparing two species?
Can you please be a little more specific? What are you comparing?
Working backwards in genetic sequences? GR.12?
No, you would not. 1. Most amino acids can be coded for by more than one codon, so you wouldn't know which codon to "untranslate" it to. 2. Even if you chose all the right codons, you'd still be missing the introns that were excised from the mRNA.
The sequences below represent the same portions of a dna molecule from the same gene used by a student to stud?
You cannot tell, because the question does not state what type of gene it is, and you have only looked at one gene. If that gene is a very conserved gene (e.g. for DNA polymerase, or another gene that is present in many organisms), then I would say that these 2 plants are not very related. If it is a gene for something not-essential, say, flower color, then the 2 species could be very closely related, if you would look at the rest of the genome. By the way, the second part of the question, about the ccgg site, did not make much sense. What is the relationship with the first part of the question?
Why must you use the same restriction enzyme on the cell dna and on the plasmid?
1. Each enzyme cuts at a specific sequence and leaves specific sticky ends. If you cut the two DNA molecules with different enzymes, their ends will not match up and they will not attach to each other effectively. 2. If you just mixed the fragments, hydrogen bonds would form between complementary bases - but these bonds are weak, and will not make up for the fact that the sugar-phosphate backbone has been cut. Ligase joins the backbones of the recombined DNA molecules.
If all the cells in our body have the same DNA, then why aren't they all the same kind of cell? How can there be different cell types, shapes, and functions?
Because each has a different subset of the whole genome turned on. Some functions are common to all cells - they will have active genes for say tubulin and spectrin, as all will have a cytoskeleton of some ilk for example - so all cells will have those genes 'turned on', though the levels of activity will differ depending on cell type. Other genes are specific to a given cell type - you only get haemoglobin in red blood cells.There is are further layer of controls over how much of a given gene product is made, all cells have tubulin, but some types will have more than others, and these regulators themselves are under genetic control.And the action of all these gene products together detrmine the form and function of the cell. And cells do chnage their gene expression over time as they are newly formed, mature and die. The way skin cells work, dividing in deeper layers and accumulating keratin as they are pushed towards the outside of the organism and eventually becoming dead slabs of keratin and flaking off is one example.An explanation with a video -What Is Cell Differentiation? - Process, Importance & Examples - Video & Lesson Transcript | Study.com These might help, but Wiki articles can be a bit impenetrable at times -Regulation of gene expression Cellular differentiation Trying to work out these processes is a major field of research as getting a fully differentiated cell back down a few steps or even all the way being a stem cell would be a very handy thing to do.http://www.wellcome.ac.uk/About-...
If you worked backward, starting with the amino acid sequence of the protein, would you obtain the same DNA..?
Although what cassie said is correct, not all organism have introns. They are a major component of the eukaryote genome but they are not present in bacteria. However you would still not be able to obtain the same DNA if you were working with the amino acid sequence from a bacteria genome. The major reason benig that multiple tripplet sequences of DNA correspond to the same amino acid. Basically each amino acid is encoded by 3 base pairs, which encode mRNA, in your example MET PHE VAL can be produced from the mRNA strand = AUG UUU GUA and the mRNA can be converted back to DNA code, this code would have come from a DNA strand TAG AAA CAT. MET PHE VAL can also be produced from the mRNA strand = AUG UUC GUG, which can then be converted back to DNA = TAG AAG CAC So you can see that the amino acid PHE can come from a DNA code of either AAG or AAA and VAL can come from a DNA code of either CAT or CAC There are many more variations possible or other amino acids. Becauce multiple DNA tripplet encode for the same amino acid it is impossible to deffinatively say what the starting DNA code was.