Question

The biogenetic law was proposed by
A. Haeckel
B. Haldane
C. Hooke
D. Schleiden

Answer 1

Hint: The biogenetic law, also called as theory of recapitulation, is based on the theory of evolution given by Darwin. This theory states that the stages starting from formation of embryo by fertilisation in an animal, to its development into an adult is just like the stages of an adult following, in the phylogenesis.

Complete answer: The theory of recapitulation or the biogenetic theory is a theory of evolution and development of an animal and was given by a German scientist Ernst Haeckel in the 1860s. Recapitulating means to summarize or conclude something. Here as the name suggests, the theory of recapitulation, means ontogeny (development of individual) recapitulates phylogeny (relation with ancestors). In other words it can be explained as the development of an individual from its embryo form to an adult is similar to the sequence of events that took place in its ancestors.
Therefore ,the correct option is (A) Haeckel.

Additional Information: By analysing the stages of embryo development, its diversification can also be studied by knowing their history. This theory also verifies that all the species present in the earth are evolved from a common ancestor. This law affirms that the stages of development of an embryo resembles the form of an adult from its evolutionary ancestor. Thus by studying the development of an embryo, one is actually studying its evolutionary history and how it diversified from its ancestors. So, one should study phylogenetic relationships between taxa and the developing stages of embryo development.

Note: Ontogeny is the development or evolution of an organism (both anatomical and behavioural) from a newborn to an adult.
Phylogeny is the relationship of an individual with its ancestors. A phylogenetic tree is commonly used to depict these relationships.