Question

1. the extract of which gymnosperm seed is used to help improve memory? ephedra cycad pine tree ginkgo

Explanation:

Ginkgo biloba extract is known for its potential cognitive - enhancing effects, including improving memory. Ephedra has stimulant properties but not mainly for memory improvement. Cycads have no such established memory - enhancing use. Pine tree extracts do not have a well - known role in memory improvement like ginkgo.

Answer:

ginkgo