Chapter 22/23 - Cellular Development Flashcards
What are the 4 steps of cellular development?
Cell division
Differentiation
Pattern formation
Morphogenesis
Describe cell division?
production of new individual cells
Meiosis: forms gametes, which will fuse to form a zygote
Mitosis: division of previously existing diploid cells
Begins post-fertilization
Describe Diferentiation.
As cells divide, changes in gene expression result in differences between cells which results in cell specialization.
In differentiated cells, certain genes are expressed at particular times, but other genes may not be expressed at all.
Cells change their gene expression to become specialized for specific functions
What am I?
Differentiation
Describe Pattern Formation.
Cells in a developing embryo must become oriented to the body plan of the organism the embryo will become
Involves cells’ abilities to detect positional information that guides their ultimate fate.
Describe Morphogenesis.
Involves: cell death, cell division, cell migration, changes in cell shape and differentiation.
organs and anatomical features will develop from dividing cells
Body is generated
Process of Development - Cell Division
In animal embryos, the period of rapid cell division following fertilization is called
cleavage
Process of Development - Cell Division
What happens to a zygote during cleavage?
- the enormous mass of the zygote is subdivided into a larger and larger number of smaller and smaller cells, called blastomeres
- The zygote maintains its size
- G1 and G2 phase during which a cell increases its mass and size, are shortened or eliminated
Process of Development - Cell Division
Process of Development - Cell Division
During cleavage, cells have extremely short G1 and G2 phases of the cell cycle due to ____________ ?
Rapid Cell Division
Process of Development - Cell Division
How many Somatic Cells does a C. Elegans, or nematode contain?
959
How are C. elegans useful in research?
- Can use them to follow or observe how each cell is derived from the fertilized egg and or the first division (of zygote) to the last cell division (full development of all structures)
Plant growth occurs in specific areas called __________?
Meristems
Process of Development - Cell Division
Undifferentiated plant tissue from which new cells arise is called ___________?
meristems
Process of Development - Cell Division
As _____________ cells continually divide, they produce cells that can differentiate into the tissues of the plant.
meristematic stem
Process of Development - Cell Differentiation
Cells become determined prior to differentiation (T/F)
true