Development of Multicellular Organisms I: General Principles of Development Flashcards
What controls development?
gene expression
The genome of all cells in an organism are identical, but what makes us different?
Expression of genes are different.
Cells have “memory”. What is this referring to?
Retain record of signals their ancestors received during embryonic development.
What does the expression of genes by a cell depend on?
Environment, both present and past.
True or False:
Homologous proteins are functionally interchangeable.
True
What is the cells that cohere to form a sheet of epithelial cells facing the external medium known as?
This sheet constitutes the ectoderm.
What is ectoderm a precursor of?
Ectoderm - precursor of nervous system and epidermis.
What structures is endoderm a precursor of?
Endoderm - precursor of gut, lung, and liver.
What is formed when a group of cells move into the space between ectoderm and endoderm?
mesoderm
What structures is mesoderm a precursor of?
Mesoderm - precursor of muscles and connective tissue.
What is gastrulation?
Transformation of a hollow sphere of cells into a structure with a gut.
What is gene duplication?
Higher organisms have several homologs of the same gene.
What term describes higher organisms having several homologs of the same gene?
gene duplication
What are the two classes of proteins that are the most important for development?
- cell adhesion and cell signaling proteins
- gene regulatory proteins (e.g., transcription factors and DNA binding proteins)
Where are the instructions for producing a multicellular animal contained?
Non-coding regulatory DNA associated with each gene.
In development, what contains regulatory elements that serve as binding sites for gene regulatory proteins?
DNA
What does regulatory DNA define for development?
Regulatory DNA defines the sequential program for development.
The coding sequences in DNA are similar in most organisms, but what makes one organism different from another?
Non-coding sequences make one organism different from another and provide uniqueness.
the coding sequences in DNA are similar in most organisms
True or False:
Cells make developmental decisions long before they show any outward signs of differentiation.
True
What does a “determined” cell mean?
Cells that are fated to develop into a specialized cell type despite changes in environment.