Brian Walker (1992) proposed the Redundancy hypothesis Species that play the same roles in a community can compensate for each other if some are lost under particular conditions

TLS Online TPP Program

#Id: 1073

#Unit 5. Developmental Biology

Class A and B activities are required for the formation of petals.

TLS Online TPP Program

#Id: 1074

#Unit 5. Developmental Biology

Class B and C activities form stamens.

TLS Online TPP Program

#Id: 1075

#Unit 5. Developmental Biology

Class C activity alone specifies carpels.

TLS Online TPP Program

#Id: 1076

#Unit 5. Developmental Biology

Many of the genes that determine floral organ identity are MADS box genes, including AG, PI, and AP3 genes of Arabidopsis

TLS Online TPP Program

#Id: 1077

#Unit 5. Developmental Biology

The MADS box gene form tetramers that bind to CC(A/T)6GG sequences, called CArG-box, in the regulatory regions of their target genes.

TLS Online TPP Program

#Id: 1078

#Unit 5. Developmental Biology

According to the Quartet Model, floral organ identity is regulated by tetrameric complexes of the ABCE proteins.