Definition

Heterospory (noun) The condition in certain plants, especially some pteridophytes (like ferns) and all seed plants, of producing two distinct types of spores: microspores (which develop into male gametophytes) and megaspores (which develop into female gametophytes). This is a key evolutionary step towards seed formation.

Usage and Examples

• Heterospory is a significant adaptation that distinguishes seed plants from many primitive vascular plants.
  • Example: The evolution of heterospory was a major step in plant reproductive biology.
• The term describes a biological characteristic.
  • Example: Selaginella exhibits heterospory, producing both microspores and megaspores.

Advanced Usage

• Heterospory is contrasted with homospory, the condition of producing only one type of spore.
  • Example: Most ferns are homosporous, while the aquatic fern Marsilea shows heterospory.

Variants and Related Words

• Heterosporous (adjective): Describing a plant that exhibits heterospory.
  • Example: Pine trees are heterosporous plants.
• Microspore (noun): The smaller spore type, giving rise to a male gametophyte.
• Megaspore (noun): The larger spore type, giving rise to a female gametophyte.

Synonyms

• There are no direct single-word synonyms. The concept is described as "the production of two spore types" or "sexual differentiation of spores."

Related Concepts (Not Phrasal Verbs or Idioms)

• Gametophyte: The haploid, gamete-producing phase in the plant life cycle, which develops from a spore.
• Sporophyte: The diploid, spore-producing phase in the plant life cycle.
• Seed Habit: The reproductive strategy of seed plants, for which heterospory is a fundamental prerequisite.

Noun

1. the development of both microspores and megaspores