Combination of Pax6, Sox2, and L-Maf in the ectoderm is needed for the production of the lens and the activation of lens-specific genes i.e. δ-crystallin.

TLS Online TPP Program

#Id: 468

#Unit 2. Cellular Organization

Introns may more freely accumulate point substitutions and other changes due to no selection pressure.

TLS Online TPP Program

#Id: 469

#Unit 2. Cellular Organization

Introns evolve or accumulate mutations/changes much more rapidly than exons

TLS Online TPP Program

#Id: 470

#Unit 2. Cellular Organization

Intron do not face selective pressure to produce a polypeptide with a useful sequence hence highly variable.

TLS Online TPP Program

#Id: 471

#Unit 2. Cellular Organization

Exon sequences are conserved by the negative selection of individuals in which the sequences have changed

TLS Online TPP Program

#Id: 472

#Unit 2. Cellular Organization

Most intron mutations are expected to be selectively neutral except branch site, splicing junctions, and sequences influencing splicing

TLS Online TPP Program

#Id: 473

#Unit 2. Cellular Organization

A mutation that confers a more advantageous phenotype to an organism, relative to Individuals in the same population without the mutation, is positive selection of that organism.