Practice Questions

Darwin proposed Pangenesis to explain how physical modifications in body parts might be communicated to reproductive cells, aligning closely with Lamarckian inheritance.

Lamarckism posits that the plant responds to the environmental dry stress by adapting its physiology (succulence) to meet its new need, then transmitting this acquired trait.

Orthogenesis (straight-line evolution) is conceptually linked to Lamarck's internal vital force, suggesting organisms have an innate drive to evolve in a specific, progressive direction.

Mutilating the tail alters somatic tissue (somatoplasm) but leaves the germplasm (reproductive cells) untouched, demonstrating that somatic changes are not inherited.

This is Lamarck's second postulate (environmental changes produce new needs, which lead to the development of new organs through effort or behavior).

Lamarckism explains vestigial organs (like the human appendix, coccyx, or wisdom teeth) as structures that lost their function and gradually degenerated due to continuous disuse over generations.

Under Lamarckism, the mental training/acquired skill of navigating the maze would be passed to the offspring, making subsequent generations progressively better at it without training.

Lamarck argued that variations are purposefully acquired during life in response to environment, whereas Darwin proposed that variations exist naturally in a population before natural selection acts.

Under Lamarckism, the disuse of wings because of terrestrial lifestyle and abundant ground-level resources led to the degeneration of wings over generations.

Genetic engineering alters the genome directly. Lamarckism refers to somatic phenotypic changes (like organ use/disuse) being converted into heritable genetic info, which does not happen here.