Question

According to Heackel's biogenetic law,
A. Development of individual metazon showed embryonic characters of ancestors.
B. Ontogeny repeats phylogeny.
C. Germplasm is immortal.
D. Every organism is produced by its parents.

Answer 1

Hint: The Heackel's biogenetic law states that each embryo's developmental stage represents an adult form of an evolutionary ancestor. That means all species on earth develop from common ancestors.

Complete answer:
In this question we have asked about Heackel' biogenetic law which is also known as theory of recapitulation or embryological parallelism. Ernst Heackel gives a biological hypothesis that in the developing stage, embryos go through different stages that resemble or represent successive stages of the evolution of their ancestors.

> Our 1st option is Development of individual metazon shown embryonic characters of ancestors. Metazon means multicellular animals. This statement is opposite of Heackel's law. This statement is saying that multicellular organisms show embryonic characters of ancestors. Biogenetic law suggests that their embryos show characteristics of their ancestors. So, this option is wrong.

> 2nd option is Ontogeny repeats phylogeny. Ontogeny is the growth and development of an individual organism. Usually, from the time of fertilization of the egg to adult and phylogeny is the evolutionary history of a species. So, this statement says that ontogeny i.e. embryonic development shows evolutionary history of a species which is exactly what Heackel's law is saying and his phrase "ontogeny recapitulates phylogeny" also says the same. So, this statement is true.

> The 3rd option is germplasm is immortal. Germplasm is living tissue from which new plants can be grown. Germplasm contains the information for a species's genetic makeup. Germ Plasm theory is a different theory. It has nothing to do with biogenetic theory. So, this option is not related to biogenetic theory.

> Option 4th, Every organism is produced by its parents. This statement is true but it is not related with biogenetic law.

So, the correct option is B, ontogeny repeats phylogeny.

Note: Heackel's law simply says that in the embryonic stage, an organism shows sequential evolution of their ancestors. It should not be confused with "germ plasm theory" or "life come from life" law.