When Lucifer yellow, a small dye, is injected into a neuron of the retina, neighboring neurons become rapidly labeled. If the retina is incubated in dopamine prior to Lucifer yellow injection, only the injected neuron becomes labeled. These findings suggest which of the following?

I. Neurons of the retina communicate via gap junctions.

II. Dopamine is transferred between cells via gap junctions.

III. Dopamine decreases the permeability of gap junctions.

TLS Online TPP Program

#Question id: 26499

#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: 26498

#Unit 3. Fundamental Processes

Which of the following shows correct bond pattern in Lactose and Allolactose

TLS Online TPP Program

#Question id: 26497

#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: 26496

#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: 26495

#Unit 3. Fundamental Processes

Which of the following is (are) required for splicing to occur?

a. two transesterification reactions

b. intact, naturally occurring introns

c. formation of a lariat like structure 

d. a branch-point G residue

TLS Online TPP Program

#Question id: 26494

#Unit 3. Fundamental Processes

Class and abundance is given Match them correctly

Class	Abundance
a. Nuclear pre-mRNA	1. Rare; nuclear rRNA in some eukaryotes, organelle genes, and a few prokaryotic genes
b. Group II introns	2. Rare; some eukaryotic genes from organelles and prokaryotes
c. Group I introns	3. Very common; used for most eukaryotic genes