OMPONENTS OF GENETIC VARIANCE 

Additive genetic variance (VA)

Dominance genetic variance (VD)

Gene interaction variance (VI)

TLS Online TPP Program

#Id: 694

#Unit 3. Fundamental Processes

Quick-stop mutants are defective in the components of the replication apparatus and cease replication immediately upon a temperature increase.

TLS Online TPP Program

#Id: 695

#Unit 3. Fundamental Processes

1. DNA polymerase I is a single polypeptide of 103 kD. 

2. The chain can be cleaved into two parts by proteolytic treatment. The larger cleavage product (68 kD) is called the Klenow fragment. It is used in synthetic reactions in vitro. 

3. It contains the polymerase and the proofreading 3’–5’ exonuclease activities.

TLS Online TPP Program

#Id: 696

#Unit 3. Fundamental Processes

1. The small fragment (35 kD) possesses a 5’– 3’ exonucleolytic activity, which excises small groups of nucleotides, up to 10 bases at a time.

2. This activity is coordinated with the synthetic/ proofreading activity. 

3. It provides DNA polymerase I with a unique ability to start replication in vitro at a nick in DNA.

TLS Online TPP Program

#Id: 697

#Unit 3. Fundamental Processes

Substitutions occurs when Proofreading fails

TLS Online TPP Program

#Id: 698

#Unit 3. Fundamental Processes

Frameshifts occurs when Processivity fails

TLS Online TPP Program

#Id: 699

#Unit 3. Fundamental Processes

Frameshifts normally occurs homopolymeric sequences as long sequence of dTn:dAn