Markush type claims

Can some please explain precisely about what markush types claims are?

Markush language is used to claim alternative elements from a group of related elements (material selected from the group consisting of A, B, and C). It was first used by Eugene Markush and hence such claims came to be known as Markush claims. A Markush claim recites alternatives in the form of an artificial generic expression, for example:

A compound having the formula:

            R-CH-N-S-X wherein

            R is an alkyl group selected from the group consisting of methyl, ethyl, and isopropyl; and

            X is a halogen selected from the group consisting of chlorine, bromine, and iodine.

A Markush group must use a closed transition, such as "consisting of," to limit the claim to encompass only those alternatives recited in the claim. The members of the Markush group should belong to a recognized physical or chemical class or to an art-recognized class or at least have one property in common which is mainly responsible for their function in the claimed relationship.

Markush technique is very effective in claiming different alternatives which cannot be described by a single generic word, yet they are functionally related (for example, in the above formula I can have R representing any of the following by writing as below:

“R is selected from the group consisting of halogen, hydroxyl, alkyloxy, aryloxy, amino, alkylamino, arylamino, mercapto, carboxyl, cyano, nitro, carbamoyl, sulpho, sulphamido, acyl, acylamino, acyloxy, alkylthio, arylthio, cycloalkyl, aryloxycarbonylamino and alkyloxycarbonylamino group”

What exactly does the viva-voce session of the patent agent exam constitutes?

Viva-voce session is an oral interview before panel members. Mostly questions are asked related to the application of patent law to the domain knowledge of the candidate. For example, if you are a biology graduate a probable question could be: Can a short DNA sequence be patented? There are some allegations about the objectivity of the viva-voce session. Please see this blog post https://spicyipindia.blogspot.com/2011/06/patent-agent-viva-sense-sensibility-and.html

I hope that the above helps~!

thank you for your guidance sir.!