Gymnosperms (naked seeds) Diverged 150 mya, when Earth became warmer and drier and the swamp forests declined. – no swimming for the sperm. Members of this group do not produce flowers and all are wind- pollinated. There are 4 distinct divisions: – Coniferophyta (cone-bearing trees and shrubs) – Ginkgophyta (flat fan-shaped leaves) – Cycadophyta (palm-like appearance) – Gnetophyta [3 distinct and unusual groups: gnetums, Welwitschia, and Mormon tea (Ephedra)]

Coniferophyta Includes pines and other cone-bearing trees and shrubs.

Ginkgophyta Flat fan-shaped leaves Native to Asia Only one extant species, Gingko biloba…. It’s a living fossil! It’s also an endangered species.

Cycadophyta Palm-like appearance Found primarily in tropical regions around the world. Some species are very endangered

Gnetophyta 3 distinct groups: Gnetum Welwitschia Ephedra

Pine Life Cycle All gymnosperms are wind-pollinated trees or shrubs, but insect pollination can happen too. Most are unisexual, with M and F reproductive structures on different parts of the same plant. They are heterosporous: male microspores develop into pollen, and female megaspores develop into the female gametophyte. The female gametophyte is not free-living, but retained within the megasporangium where it is nourished by the sporophyte parent plant.

Angiosperms Phylum (division) Anthophyta  Nope. The carpel, a vessel in which the ovules are enclosed, is unique to angiosperms. After fertilization the ovule develops into a seed (like gymnosperms), while the carpel matures into a fruit (unique to angiosperms)

Angiosperm flowers Flowers are composed of both male and female reproductive structures Many flowers are self-fertile, but cross-fertilization is important in maintaining genetic diversity. Pollinators, such as birds, insects, and mammals help transfer pollen from flower to flower. (~85% of it, actually)

2) Alternation of generations (Angiosperms) Microsporangium (anther) Megasporangium (carpel) Pollen Ovules Ovary Embryo Fruit Endosperm (3n) GAMETOPHYTE (n) SPOROPHYTE (2n) Seed Coat (from mom) Mature Sporophyte Embryo Endo. Pollen Tube