Phase-contrast microscopy is suitable for observing which kind of sample?

1. Single cells 

2. Group of cells

3. Thin cell layers

4. Thick cell layers

Which of the following options is correct?

TLS Online TPP Program

#Question id: 24489

#Unit 3. Fundamental Processes

Two transesterification reactions takes place for 2 exon -1 intron configuration. Choose the correct  statement 

a. First transesterification is always caused by exon 1 -3’OH

b. second transesterification is catalysed variably either by external G or branch point while .

c. First transesterification is catalysed variably either by external G or branch point while 

d. second transesterification is always caused by exon 1 -3’OH.

TLS Online TPP Program

#Question id: 24490

#Unit 3. Fundamental Processes

There are three type of Splicing signals 1. Major U2-type or GU-AG introns 2. Minor U12-type or AU-AC introns & 3. Minor U12-type with GU-AG introns (hybrid type), which of the following is responsible for the recognition of branch point sequence UACUAAC?

TLS Online TPP Program

#Question id: 24491

#Unit 3. Fundamental Processes

There are three type of Splicing signals 1. Major U2-type or GU-AG introns 2. Minor U12-type or AU-AC introns & 3. Minor U12-type with GU-AG introns (hybrid type), which of the following is responsible for the recognition of branch point sequence CCUUAACU

TLS Online TPP Program

#Question id: 24492

#Unit 3. Fundamental Processes

Splice sites are directional in nature. 5’ splice site -the left, or donor, site and the 3’ splice site - right, or acceptor, site. So, in below table the complex and their events are given match them correctly .

TLS Online TPP Program

#Question id: 24493

#Unit 3. Fundamental Processes

Splice sites are directional in nature. 5’ splice site -the left, or donor, site and the 3’ splice site - right, or acceptor, site. 

1. U2 addition to base pair with the branch site in the presence of ATP

2. U1 and U4 release Formation of the catalytic center in which U6 base pairs with the 5' splice site; U6 also base pairs with U2; U2 remains base paired with the branch site; U5 interacts with both exons through its loop.

So, 1 and 2 are the event of complex formation which are 

TLS Online TPP Program

#Question id: 24494

#Unit 3. Fundamental Processes

U1 and U4 release Formation of the catalytic center in which U6 base pairs with the 5' splice site; U6 also base pairs with U2; U2 remains base paired with the branch site; U5 interacts with both exons through its loop is the characterstic of one of the stage during splicing, which is