21.2

Totipotency

• totipotent= can give rise to all specialized cell types

Plant cells- mature cells can dedifferentiate

and show totipotency

Transcriptional Regulation

Determination and differentiation

• determination-events that lead up to differentiation
• Differentiation- expression of genes for tissue specific proteins
• proteins then give rise to specific structure and function for purpose

Cloning

Reproductive Cloning of Mammals

• Cloning- using somatic cells to make a genetically identical individual

21.2

Cell Differentiation

• Nucleus of differentiated animal cell can sometimes give rise to new animal if transplanted to a enculeated egg cell

Stem Cells

Pluripotent- give rise to many but not all cells

Adult stem cells are pluripotent

Are animal cells totipotent?

• Remove nucleus from an unfertilized egg
• Replace it with a nucleus of differentiated cell

Results

• If nucleus from differentiated donor cell retains in full genetic capability then it should be able to direct development of the recipient egg into all the proper tissues