gemmule

/'dʤemju:l/

Thân thiện

A scientist examines a diagram of a gemmule under a magnifying glass.

Definition

1. Noun:
   • A small bud or reproductive body in some plants and invertebrates: In biology, a "gemmule" is a small, asexual reproductive structure, such as a bud or a resistant cluster of cells, that can develop into a new organism. This is the primary biological meaning.
   • A hypothetical unit of heredity: Historically, in the context of Darwin's theory of pangenesis, a "gemmule" was conceived as a minute particle shed by body cells that collected in the reproductive organs and was responsible for transmitting hereditary characteristics to offspring. This usage is now archaic.

Examples of Usage

• Noun (Biological Structure):
  • Sponges can reproduce asexually by forming gemmules that survive harsh conditions.
  • The botanist observed the gemmule developing at the base of the fern leaf.
• Noun (Historical Biological Theory):
  • Darwin's theory involved gemmules traveling from somatic cells to the germ cells.

Advanced Usage

• In historical scientific discourse: The term is used almost exclusively when discussing the history of evolutionary biology and genetics, particularly in reference to Darwin's provisional hypothesis of pangenesis.
  • The concept of the gemmule was an early, albeit incorrect, attempt to explain the mechanism of inheritance.

Variants and Related Words

• Gemmulation (n): The process of forming gemmules.
• Gemmiferous (adj): Bearing or producing gemmules or buds.

Synonyms

• Bud (in the botanical sense).
• Propagule (a vegetative structure that can become a new plant).
• Hypothetical particle / Hereditary unit (in the historical Darwinian context).

Related Idioms or Phrases

There are no common idioms or phrasal verbs using the word "gemmule." It is a specialized scientific term.

Học thuật

Noun

1. the physically discrete element that Darwin proposed as responsible for heredity