PCR VS DNA sequencing

PCR starts with a double stranded DNA but DNA sequencing starts with a single-stranded DNA. Both methods require DNA polymerase and nucleotides. PCR require primers but DNA sequencing require radioactively labeled primer and dideoxynucleotides that stop the event of elongation as they do not have a 3’-OH in the structure. PCR is a cycle but DNA sequencing is not. Different form PCR with repetitive heating, cooling and replication, DNA sequencing needs to undergo gel electrophoresis and autoradiography.

PCR VS Vector Cloning

Vector cloning is best for preparing a large quantity of the desired gene, however if the DNA is impure, PCR will then be a quicker method as it does not require cells. PCR can make a lot of copies before vector cloning starts and less time consuming as you do not need to find the desired gene and then clone it. PCR can be used even there is only a small amount of DNA. However, errors will happen during DNA replication, the number of desired copies may not be satisfactory. Vector cloning is a more accurate method.

Deaf by design

After hearing the presentation on deaf by design, I cannot help thinking about the ethical issues brought up by the new generation in the deaf families. I can truly understand that why the deaf people are so eager to find a spouse and give birth to deaf children, in which they can find likeliness of each other. However I am strongly against them to abore fetus without listening disabilities, it is just that they are different from their family members do not mean they do not have the right to live. In addition, they are the ones who are regarded as normal by the general public. On the other hand, I really feel enraged when the parents actually persuade their child not to have cochlear implant and knock down their child’s confidence. If it is the will of the child to have the opportunity to listen to the wonderful voices in the world, why don’t give her a chance of the parents are able to do so. The child should have the right to choose the pathway of her own future.

Genetics Test

DNA Replication

DNA polymerase III catalyses the elongation of new DNA at a replication fork

DNA strands grows form 5’ to 3’ direction

Leading strand- copied into the direction of the fork continuously from a single primer

Lagging strand- copied away from the fork in short segments called Okazaki fragments, each requiring a new primer

                                                                  DNA Transcription

Transcription: initiation, elongation and termination

Transcription factors recognizes the 5’ TATA 3’ box

Terminator sequence AAUAA

A 5’ cap is at the 5’ end of the pre-mRNA molecule

A poly(A) tail is at the 3’ end

                                                                 DNA Translocation

mRNA is read from 5’ to 3’ codon by codon

The P site on ribosome holds the tRNA with the polypeptide chain

The A site has the tRNA with the next amino acid

It is at the E site where tRNA is discharged