Stages of Embryology
what do vertebra embryos have in common?
In stage one all embryos have gill slits and a tail
what was Von Baer known as?
founding father of embryology"
What is comparative embryology?
The study of developing embryos
What is an embryo?
Early stage of a developing multicellular organism
Who was Von Baer?
Naturalist, biologist, geologist, meteorologist and geographer
what are 4 limbed vertebras called?
What is tetrapods
What is the first stage of embryology called?
1st- general characteristics appear sooner on an embryo then specialized features do.
2nd- embryos develop from a simple structure to a complex organism
Why do gills cease to develop in vertebras other then fish?
Overtime gills were no longer needed in many species because of their environments and they ceased to develop.
What is the final stage of embryology?
Fetal period, when specialized features have developed
What was Von Baers 3rd law?
The presence of gills in human embryos is because fish and humans share a common ancestor showing evolution
what does comparative embryology tell us about evolution?
It provide evidence for common ancestry
what do all final forms of tetrapod's have in common with each other?
they were all build from the same set of embryonic tissues and are supported by the same set of bones and muscles
What was Von Baer's fourth law?
The resemblance of different embryos of higher grade and primitive ones show that higher embryos are related to primitive animals.
What does comparative embryology tell us about common ancestry?
Because it shows that the embryos still have many common traits even though they may not persist as they grow