Misconception in understanding evolution
How can we define Evolution !!
I thought evolution is what lamarck described in its theory.
Use and disuse of an organ leads to the change in its shape later that was acquired by next generation .Like short neck girafee changes to long neck girafee.
Later on CUBE Chatshaala discussion i understood that what a wrong concept that i was having about evolution .
We started discussion with how darwin finches changes its beak shape ??
In yesterday’s chatshala discussion we tried to found out our misconception regarding evolution .
1) First confusion was that based on the food a bird can choose to change the shape of beak
2) Second was that not only the shape of the beak can be changed based on the choice, but also once such shape is chosen that shape gets inherited in the next generation
Then we understood that probably a mutation is occuring, that is leading to the variations among finches .
Later we came across how mutation is happening !!!
Later on discussion @shalinisharma made a great attempt regarding how mutation in beta chain of heamoglobin leads to Sickel shaped RBC.
Following Summary written by Shalini
We started our discussion with Beta chain of Hb and wanted to know from where this beta has came in the story of sickle cell anemia.
So our Hb protein is composed of 2 chains of alpha and beta each.
What is this alpha and beta chain?
It is a polypeptide chain of amino acid which differs in the sequence of amino acid.
What does mean by polypeptide?
What is happening to Hb protein when there is valine (Val) instead of glutamic acid (Glu)? What is causing the RBC to become sickle shaped?
Then, we discussed about the structure of both the amino acids. (Glu) is a polar amino acid while (Val) is non-polar amino acid. there is change in polarity of amino acid which is causing structural change that is not allowing the alpha and beta chains to arranged in prope structure as it before.
Now, how does amino acids link (peptide linkage) to each other what chemical reaction takes place? And when we call dipeptide (two amino acids linked by one peptide bond), tripeptide (3 aa , 2 peptide bond), and so on.