The arguments supporting spontaneous generation were finally disproved by

A. Glycocalyx: The glycocalyx is a sticky, gelatinous layer found external to the cell wall in some bacteria and eukaryotic cells. It is primarily composed of polysaccharides and sometimes proteins. This structure functions in adherence to surfaces, protection against desiccation, and evasion of host immune responses, making it essential for colonization and virulence in pathogenic microbes.

B. Capsule: A capsule is a well-organized, dense form of glycocalyx that surrounds certain bacterial cells. While all capsules are glycocalyx, not all glycocalyx is a capsule; the term “capsule” specifically refers to a structured, tightly bound layer that provides enhanced protection and virulence.

C. Membrane: The membrane, including the plasma or cytoplasmic membrane, is a lipid bilayer that controls selective permeability and transport. It is not the sticky, gelatinous external layer.

D. Viroid: A viroid is an infectious, small circular RNA molecule that infects plants. It is unrelated to cellular coatings or structural layers and does not consist of polysaccharides or proteins.

A. Louis Pasteur: Louis Pasteur definitively disproved spontaneous generation in the 19th century through experiments using swan-neck flasks. He demonstrated that sterilized nutrient broth remained free of microbial growth when protected from airborne microorganisms, proving that microorganisms arise from other microorganisms, not spontaneously.

B. Francesco Redi: Francesco Redi conducted 17th-century experiments showing that maggots on meat developed only when flies had access to it. While his work challenged spontaneous generation for larger organisms, it did not definitively disprove it for microorganisms.

C. Rudolf Virchow: Rudolf Virchow proposed the principle “Omnis cellula e cellula,” stating that all cells arise from preexisting cells. This addressed cellular reproduction but did not directly test or disprove spontaneous generation of microorganisms.

D. John Needham: John Needham performed experiments in the 18th century that he interpreted as supporting spontaneous generation. He boiled broth and observed microbial growth afterward, failing to fully sterilize the solutions, which later experiments revealed.

E. Lazzaro Spallanzani: Lazzaro Spallanzani improved on Needham’s experiments by boiling broth in sealed flasks, preventing microbial growth. His work strongly suggested that microorganisms came from the environment, but Pasteur’s swan-neck flask experiments provided the final, widely accepted disproof.