Lesson 8: Development
1. Timing and coordination of specific events are necessary for the normal development of an organism, and these events are regulated by a variety of mechanisms.
a. Observable cell differentiation results from the expression of genes for issue-specific proteins.
Cell differentiation occurs as a result of differential gene expression. Each individual cell is specifically developed for a specialized function from a specific protein. This protein is made specifically for that one purpose and that one cell. Because genes are able to turn on and off genes, cells are able to be individualized.
b. Induction of transcription factors during development results in sequential gene expression.
Homeotic genes are any master regulatory genes that control placement and spatial organization of body parts in an organism; they control the developmental fate of each group of cells. Because of this ability, they are able to control the pattern formation in the late embryo, larva, and adult. The discovery of these genes helped to support the idea that genes direct the developmental process.
c. Programmed cell death plays a role in the normal development and differentiation.
Apoptosis is a type of programmed cell death brought about by activating enzymes that break down several chemical components in the cell. Apoptosis plays a major role in the proper development of fingers and toes. During finger and toe development, the tissue in between each finger and toe needs to be removed; it is removed by apoptosis.
a. Observable cell differentiation results from the expression of genes for issue-specific proteins.
Cell differentiation occurs as a result of differential gene expression. Each individual cell is specifically developed for a specialized function from a specific protein. This protein is made specifically for that one purpose and that one cell. Because genes are able to turn on and off genes, cells are able to be individualized.
b. Induction of transcription factors during development results in sequential gene expression.
Homeotic genes are any master regulatory genes that control placement and spatial organization of body parts in an organism; they control the developmental fate of each group of cells. Because of this ability, they are able to control the pattern formation in the late embryo, larva, and adult. The discovery of these genes helped to support the idea that genes direct the developmental process.
c. Programmed cell death plays a role in the normal development and differentiation.
Apoptosis is a type of programmed cell death brought about by activating enzymes that break down several chemical components in the cell. Apoptosis plays a major role in the proper development of fingers and toes. During finger and toe development, the tissue in between each finger and toe needs to be removed; it is removed by apoptosis.