Practice Questions

Lamarck was a pioneer who proposed the first fully formed, systematic theory of organic evolution, paving the way for evolutionary thought despite his proposed mechanisms being incorrect.

Since the offspring of the salt-stressed plant reverted to normal thin leaves when grown in normal soil, the acquired trait (thick leaves) was not inherited, refuting Lamarck's theory.

Lamarck's theory is widely known as the "Theory of Inheritance of Acquired Characters" or simply "Lamarckism."

Lamarck believed that all living organisms possess an innate, vital force that drives them to become more complex, organized, and structurally perfect over time.

Hypertrophy from physical work is a somatic adaptation (phenotypic plasticity). It does not alter germ-line DNA, so the children must still build their own muscles through work.

Weismann established that only the genetic material in germ cells (sperm and egg) is passed to offspring; changes in somatic cells (like muscle or nerve) die with the individual.

Lamarck's "Philosophie Zoologique" was published in 1809, which is in the early 19th century.

The kiwi bird lives on the ground with few predators; its lack of flight led to the disuse of wings, causing them to shrink and become vestigial over generations.

Herons stretched their legs constantly to stay dry while wading in water. Under Lamarck's "use" principle, this stretching elongated the limbs, a trait passed to subsequent generations.

The Central Dogma states that genetic information cannot flow backward from proteins (somatic phenotype) to DNA (germline genotype), making Lamarckian inheritance of somatic changes molecularly impossible.