In frog, the vertebra with an anterior convex surface (i.e., double convexties) is
atlas
urostyle
8th vertebra
9th vertebra
RBC's are nucleated in
man
rat
frog
rabbit
C.
frog
RBC in man is anucleated. Nucleated RBCs are found in camel and amphibians (e.g. frog). In frog, RBCs are typically flattened and more or less eliptical in shape but it appears biconvex when seen along its edge. They filled with cytoplasm of faint straw colour and contains a definite round nucleus in centre.
The first phylogenetic system of plant classification was proposed by
Engler
Engler and Prantl
Eichler
Wetlstein