Development of Multicellular Organisms I Flashcards
How do cells have memory?
Retain record of signals their ancestors received during embryonic development.
Remember the environment
Homologous proteins are functionally _________.
Interchangeable
What constitutes the ectoderm?
Cells that cohere to form a sheet of epithelial cells facing external medium
Ectoderm is a precursor of what?
precursor of nervous system and epidermis
What constitutes the endoderm?
Part of the epithelial sheet becomes tucked into the interior
What is the endoderm a precursor of?
Gut, lung, and liver
What forms the mesoderm?
Group of cells move into the space between ectoderm and endoderm and form the mesoderm
What is the mesoderm a precursor of?
Muscles and connective tissue
What is gastrulation?
Transformation of a hollow sphere of cells into a structure with gut
Higher organisms have several homologs of the same gene called what?
gene duplication
What are two classes of proteins most important for development?
Cell adhesion and cell signaling proteins
Gene regulatory proteins
Where are instructions for producing a multicellular animal contained in?
In the non-coding regulatory DNA associated with each gene
DNA contains regulatory elements that serve as binding sites for what/
gene regulatory proteins
What defines the sequential program for development?
Regulatory DNA
Coding sequences in DNA are similar in most organisms but non-coding sequences make one organism what?
different from one another and provide uniqueness
Cell that are fated to develop into a specialized cell type despite changes in environment are called what?
Determined
cells make developmental decisions long before they show any outward signs of differentiation
Cells that can change rapidly due to alterations in environment are called what?
Completely undetermined
Cells that have some attributes of a particular cell type but can change with environment are called what?
Committed
Before acquiring a particular fate, cells express genes that are markers of their location, they are ______.
regionally determined
What is a position specific character of a cell called?
positional value
Cell can become different due to ________ division. These are significant sets of molecules distributed unequally between daughter cells
asymmetric
How can cells born the same can become different?
Due to change in environment after birth
*these molecules then directly or indirectly alter pattern of gene expression between the 2 cells
What are the most important environmental cues to a developing cell?
Signals from neighboring cells
Whats the term?
Induction of a different developmental program in select cells in a homogeneous group leading to altered character
inductive signaling
*few cells closest to the source take on induced character-signal is limited in time and space
