Concepts In Embryology Flashcards
What is the first Von Baer’s Law?
The general features of a large group of animals appear earlier in development than do the specialised features of a smaller group
What is ontogeny?
The entire sequence of events involved in the development of an individual organism
What is phylogeny?
The sequence of events involved in the evolutionary development of a species or taxonomic group of organisms
What is metamerism?
An initial subdivision of the embryonic body into an ordered series of equal segments (metameres)
How does a fertilised egg give rise to the adult body?
Anatomical approaches, experimental approaches and developmental approaches
How are different parts of an embryo formed?
Everything is preformed and gets bigger during development and new structures arise progressively
What is the dorsal blastopore lip?
The organiser
Where is the dorsal blastopore lip grafted on?
On to the ventral side of an unpigmented host embryo
What does a dorsal blastopore induce?
An extra embryonic axis containing a new neural tube
What is the Hox code?
A group of genes that control the body plan of an embryo
What is the second Baer’s Law?
Less general characters develop from the more general until finally the most specialised appear
What is the third Baer’s law?
The embryo of a given species, instead of passing through the adult stages of lower animals, departs more and more from them
What is the fourth Baer’s law?
The early embryo of a higher animal is never like a lower animal, but only like its early embryo
Name the approaches to study embryology
Von Baer’s laws, ontogeny and phylogeny, Hans Spemann’s organiser, metamerism and Hox code
What details are provided by embryology?
Prenatal and postnatal development changes
