Section 8 - Development Flashcards
What is cleavage?
Cell division into a larger number of smaller cells
What is a solid ball of cells called?
A hollow ball of cells?
A morula
A blastula
What are the stages of cleavage?
2-cell stage, 4-cell stage, 8-cell, 16-cell
What are the stages of vertebrate development?
Cleavage
Formation of the blastula
Gastrulation
Organogenesis
Neurulation
What is a protostome?
An organism where the blastopore (first opening) becomes the mouth
What is a deuterostome?
An organism whose blastopore (first opening) develops into an anus
What is a blastocoel?
The hollow cavity inside a blastula
Where does the blastocoel form in an animal?
Near the animal pole, opposite the vegetal pole
What is gastrulation?
When one wall of the blastula pushes inward
What are the three germ layers that form from Gastrulation?
Endoderm - inside layer
Mesoderm - middle layer
Ectoderm - outside layer
What do the three derm layers form?
Endoderm - internal organs
Mesoderm - bones, blood vessels, muscles
Ectoderm - skin, nervous system
What is an amnion?
The innermost membrane that forms to protect an embryo from the outside environment
What is organogenesis?
The formation of tissues into organs
What is neurulation?
When the cells above the notocord roll into a tube that then separates
This is the neural tube that becomes the spinal cord
What is the “Law of Biogenics”
“Ontogeny recapitulates phylogeny”
