Essential Knowledge 1.B.1

Organisms share many conserved core processes and features that evolved and are widely distributed among organisms today.

Structural and functional evidence supports the relatedness of all domains.DNA and RNA are carriers of genetic information through transcription, translation and replication. Major features of the genetic code are shared by all modern living systems. Metabolic pathways are conserved across all currently recognized domains.

Structural evidence supports the relatedness of all eukaryotes. Illustrative examples can include:

• Cytoskeleton (a network of structural proteins that facilitate cell movement, morphological integrity and organelle transport)
• Membrane-bound organelles (mitochondria and/or chloroplasts)
• Linear chromosomes
• Endomembrane systems, including the nuclear envelope.

Students should be able to:

LO 1.14 Pose scientific questions that correctly identify essential properties of shared, core life processes that provide insights into the history of life on Earth.

LO 1.15 Describe specific examples of conserved core biological processes and features shared by all domains or within one domain of life, and how these shared, conserved core processes and features support the concept of common ancestry for all organisms.

LO 1.16 Justify the scientific claim that organisms share many conserved core processes and features that evolved and are widely distributed among organisms today.