Same day, different lectures

The topic was on Genetic transfer and recombination. In all of the mechanism, transferred involved; --donor cell- that give a portion of its total DNA --recipient cell- that received a portion of DNA from donor cell --parts of donor DNA is incorporated into the recipient DNA --when some of the donor’s DNA has been integrated into the recipient’s DNA, the resultant cell is called a recombinant.

Genetic transfer in prokaryotes:

 

•Transformation –gene transfer from one bacterium to another as ‘naked’ DNA in solution

 •Transduction –donor DNA transfer is mediated by a virus   

       

                                                              

 •Conjugation –transfer involve cell to cell contact –conjugative plasmid is the donor cell

                                                              

Dr Wan is back (for a while) :D

The class was with Dr Wan because Dr Wan wanted to finish virus topic. But we have prepared a mind map few weeks earlier. This is it.

I find this topic interesting because we get to know that virus is not the same with bacteria. Both can cause disease or illness, but in different way. Virus is not living cells. Mechanism used for viral multiplication depends on viral structure and genome •  The steps are – attachment to host cell – entry – uncoating of genome – synthesis  – assembly – release.  I also always interested in cancer disease because actually, al of us have cancer cell, but then whether it is active or inactive. And to make it stay inactive, we should live a very healthy lifestyle. So basically things are depends on us eventually. Sooooooo yes, this is all for this lecture because I have one more lecture to write on hehehehe.

Third lecture

Our third lecture with Prof Katty was on mutation. Mutation is any inheritable change in the base sequence of DNA. It can be spontaneous (occurs without a mutagen)  or induced (chemical and physical agents to induced the mutation) .

Types of Mutations:

Base substitutions (a single base at one point in the DNA sequence is replace with a different base) There are three types under this mutation which are silent, missense, nonsense.

Frameshift mutation: insertion or deletion, shift in the reading frame

Types of mutagens: base analogues, chemical mutagen, radiation, intercalating agents.

To identify mutants, detection by selecting or testing for an altered phenotype. Two kinds which are nonselectable and selectable ( positive selection and negative selection).  

Positive (direct) selection- isolate mutants that require amino acids or other growth factors (parent cannot grow)

Negative(indirect selection)- nutritional mutant, inability to grow in agar plate lacking the nutrient (parent grow). 

Well basically this is the summary of this morning class.