Balance natural selection

Balancing selection is a type of natural selection that maintains genetic diversity in a population.

In balancing selection, two or more alleles are kept in balance, and therefore are  maintained in a population over the course of many generations.

TLS Online TPP Program

#Id: 6479

#Unit 3. Fundamental Processes

Constitutive active housekeeping genes and developmentally regulated genes have TATA-less promoters 

TLS Online TPP Program

#Id: 6480

#Unit 3. Fundamental Processes

TLS Online TPP Program

#Id: 6481

#Unit 3. Fundamental Processes

TATA less, Inr Less promoters uses Sp1 activator to position TBP with TAFs

TLS Online TPP Program

#Id: 6482

#Unit 3. Fundamental Processes

Sp1 contains three zinc fingers, 25% of their amino acid residues are Gln

TLS Online TPP Program

#Id: 6483

#Unit 3. Fundamental Processes

For RNA polymerase II, the positioning factor is TFIID, which consists of TBP associated with up to 14 other subunits called TAFs (for TBP -associated factors). 

TLS Online TPP Program

#Id: 6484

#Unit 3. Fundamental Processes

The total mass of TFIID typically is -800 kD

TAF has 2 enzymatic activities:

Histone acetyltransferase

Protein kinase