-cell division, cell differentiation, and morphogenesis.
What is CELL DIFFERENTIATION?
-process by which cells become specialized in structure and function.
-differentiation is controlled by turning specific sets of genes on or off.
What is MORPHOGENESIS?
creation of form.
What is SOMATIC CELL NUCLEAR TRANSFER?
-an egg cell has its nucleus removed and is fused with an adult cell containing a nucleus and DNA.
-the fused cell then starts to develop as an embryo and is implanted in a surrogate mother.
What determines which genes are expressed in a particular cell?
-early in development: maternal molecules (RNA or protein) with uneven distribution in the egg can influence patterning.
-later in development: cytoplasmic determinants (asymmetrically distributed proteins) or induction signals from nearby cells.
What sets up the axis in fruit flies?
-asymmetric distribution of bicoid RNA and protein.
-bicoid gene forms the head and is a maternal effect.
What is a MORPHOGEN?
-diffusable substance whose local concentration affects the course of local development in organism.
-example is BICOID.
-head has high levels of bicoid; chest has intermediate, abdomen has low.
What are HOMEOTIC GENES?
-control the overall body plan in animals by controlling the developmental fate of cells in specific segments.
-homeobox (polarity and segmentation).
-hox genes.
What are CYTOPLASMIC DETERMINANTS?
-maternal substances in the egg that influence the course of early development by regulating the expression of genes that affect the developmental fate of cells.