Question

Which one of the following statement is correct?

विकल्प

• there is no evidence of the existence of gills during embryogenesis of mammals.

• all plant and animal cells are totipotent

• ontogeny repeats phylogeny

• stem cells are specialised cells

Answer 1

Ontogeny repeats phylogeny

Explanation:

The recapitulation theory, associated with Haeckel, states that ontogeny recapitulates phylogeny. The other choices are incorrect: vertebrate embryos show pharyngeal structures, not all cells are totipotent, and stem cells are unspecialised.