1. A thick-walled spore formed by the union of two gametes in certain algae and fungi, serving as a resting stage.
Usage: biology; botany

Examples

• The oospore develops when the egg cell is fertilized by the sperm cell in the oomycete.
• Oospores are highly resistant to environmental stress and can survive harsh conditions.
• In water molds, oospores germinate to produce new hyphae when conditions improve.
• The formation of oospores is a key reproductive strategy for many algal species.
• Scientists observed the thick walls of oospores under the microscope, which protect the developing embryo.