ch 21.1-3: genes, development, and evolution Flashcards
development
allows a multicellular individual to form from one cell
zygote
a fertilized egg which divides and forms a ball of cells called an embryo
evolutionary development biology
compares developmental processes and mechanism in different organisms
differentiation
the process in which an unspecialized cell becomes a distinct specialized cell type
- usually by changes in gene expression
differential gene expression
expression of different sets of genes in cells within the same genome
- responsible for creating cell types
genetic equivalence
when all different cells types of a multicellular individual possess the same genome
de-differentiate
process of reversing the normal course of cell specialization
what different levels do eukaryotic cells regulate gene expression?
- chromatin condensation
- transcriptional control
- alternative splicing
- selective destruction of mRNAs
- translation rate
- activation and deactivation of proteins
what is the basis of epigenetic inheritance?
chromatin condensation patterns
- also important for differentiation
developmental processes in every multicellular organism
- cell division
- cell-cell interactions
- cell differentiation
- cell movement and changes in shape
- programmed cell death
cell division
cells divide by mitosis and cytokinesis
what is regulated in cell division
timing, location, and amount of cell division
what regulates progression through cell cycle?
cell cycle checkpoints
how do cells initiate mitosis?
M-phase promoting factor
how is cell division controlled?
cells respond to signals from other cells
cell-cell interactions
signals that are produced by cells influence their neighbors to divide, differentiate, move, expand or die
where can receptors be?
inside the cell or on its surface
how do cells interact during development?
through signaling molecules
- diffuse through watery environment around cell
- present on surface of other cells
- can be bound to the extracellular matrix
cell differentiation
most cells differentiate and specialize
two mechanisms for specifying cell fate
- cytoplasmic determinants
- induction
cytoplasmic determinants
regulatory molecules that are unequally distributed to daughter cells
induction
one daughter cell receives a signal that the other does not
cell movement
- during gastrulation, cells rearrange into three layers
- later in development, some animal cells migrate to far locations
do plant cells move?
no, but they control changes in cell shape and orientation of cell division
