49) In chickens, the wings develop from a zone of : 1380976.
49) In chickens, the wings develop from a zone of polarizing activity (ZPA).
50) Homeobox sequences vary widely from one species to another.
51) Versions of homeobox genes have been found in plants and fungi.
52) Without cell adhesion, the primitive gut probably wouldn’t develop during gastrulation.
53) Eye cells can become beak cells once they are committed.
54) Cell death during development will always have negative, possibly fatal, effects on normal development.
55) Cells become more and more specialized as development progresses.
56) Different cell layers may have different cell adhesion molecules.
57) Menopause and puberty are both examples of developmental changes.