[Solved] The mean of a sample is the middle value when the data are arranged in ascending or descending rank order. Cycads: Ancient seed plants with a large crown of compound leaves and a stout trunk, often mistaken for palms or tree ferns. Ginkgo: A member of an ancient gymnosperm group that consists of a single living representative (Ginkgo biloba), a hardy, deciduous tree with broad, fan-shaped leaves and naked, fleshy seeds (on female trees) Nonmotile Sperm: Sperm cells that lack the ability to move or swim, which can affect fertilization capabilities. Pollen Grains: Microscopic structures that carry the male gametes of seed plants and are necessary for fertilization.