Regional specificity of induction:

mesenchyme plays an instructive role, calling into play different sets of genes in the responding epithelial cells.

TLS Online TPP Program

#Id: 2229

#Unit 11. Evolution and Behavior

The Birth of a Gene - Duplication is the most common way that new genes arise in eukaryotes. 

TLS Online TPP Program

#Id: 2230

#Unit 11. Evolution and Behavior

The Birth of a Gene- Whole genome duplication, Horizontal gene transfer, De novo genes

TLS Online TPP Program

#Id: 2232

#Unit 11. Evolution and Behavior

De novo genes -New Genes in organisms ranging from yeast to humans that did indeed originate from noncoding DNA,

TLS Online TPP Program

#Id: 2234

#Unit 11. Evolution and Behavior

Nucleotide changes, particularly those at the third position of the codon, that do not alter the amino acid sequence are called synonymous substitutions.

Nucleotide changes in a gene that alter the amino acid sequence of a protein are referred to as non-synonymous substitutions.

TLS Online TPP Program

#Id: 2236

#Unit 11. Evolution and Behavior

Highest rates of substitutions in regions of the gene that have the least effect on function, such as the third position of a codon, flanking regions, and introns.

TLS Online TPP Program

#Id: 2237

#Unit 11. Evolution and Behavior

Neutral selection (Ka/Ks = 1)

Positive selection (Ka/Ks > 1)

Purifying selection (Ka/Ks < 1)