Question

Biogenetic law states that

• A. Ontogeny repeats phylogeny.
• B. Phylogeny repeats ontogeny.
• C. No two living organisms are alike.
• D. The favourable acquired characters are inherited.

Answer 1

Answer: (A)

Ontogeny repeats phylogeny.

Haeckel proposed biogenetic law which states that ontogeny repeats phylogeny. Here, ontogeny refers to life history of an individual and phylogeny is the history of evolution of the individual. Therefore, all organisms recapitulate evolutionary history of their race in abbreviated form during their development. This makes option A correct and option B incorrect.

Sexually reproducing organisms exhibit variations and are not alike. Crossing over and independent assortment of chromosomes during meiosis and random fertilization of gametes are the basis of variations among sexually reproducing organisms. This makes option C incorrect.

According to the theory of inheritance of acquired characters, as given by Lamarck, individual acquire characters under influence of needs as posed as changing environmental conditions, these characters are inherited. He explained evolution of the long-necked giraffes from short-necked giraffes, on the basis of his theory; option D is incorrect.

Therefore, the correct answer is option A.