Definition

1. Noun:
   • A thick-walled sexual spore that develops from a fertilized oosphere in some algae and fungi: An oospore is a specialized, durable reproductive cell formed after fertilization. It is characterized by a thick protective wall and serves as a resting stage, allowing the organism to survive unfavorable conditions.

Examples of Usage

• Noun:
  • The formation of an oospore marks the completion of sexual reproduction in many water molds.
  • Under the microscope, the thick-walled oospore was clearly visible within the fungal tissue.
  • The oospore can remain dormant in the soil for several seasons before germinating.

Advanced Usage

• In plant pathology: The term is often used to describe the survival structure of certain plant-pathogenic oomycetes (like or species).
  • The pathogen overwinters as an oospore in plant debris.

Variants and Related Words

• Oosphere (n): The female gamete or egg cell in certain algae and fungi, which is fertilized to form the oospore.
• Oogamous (adj): Referring to a type of sexual reproduction involving a large, non-motile female gamete (oosphere) and a smaller, motile male gamete.
• Zoospore (n): A motile asexual spore, often contrasted with the non-motile, sexually-derived oospore.

Synonyms

• Resting spore: A general term for a spore with a thick wall that enters a period of dormancy.
• Zygote: In this specific context, the oospore is the zygote (fertilized cell) of these organisms, though "zygote" is a more general biological term.

Notes on Meaning

• The term is highly specific to botany, mycology, and microbiology. It refers exclusively to the product of fertilization in certain groups of algae and fungi (particularly oomycetes). It is not used in the context of animal or higher plant reproduction.

Noun

1. a thick-walled sexual spore that develops from a fertilized oosphere in some algae and fungi