Plant Diversity

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Slide 23

Ferns and Their Relatives

Seedless vascular plants include:

club mosses

horsetails

ferns

Slide 24

Ferns and Their Relatives

The most numerous phylum is the ferns.

Ferns and their relatives have true roots, leaves, and stems.

Slide 25

Life Cycle of Ferns

Ferns have vascular tissues, strong roots, underground stems called rhizomes, and leaves called fronds.

Slide 26

Life Cycle of Ferns

Ferns and other vascular plants have a life cycle in which the diploid sporophyte is the dominant stage.

Slide 27

Life Cycle of Ferns

Fern sporophytes develop haploid spores on the underside of their fronds in structures called sporangia.

Sporangia are grouped into clusters called sori.

Slide 28

Life Cycle of Ferns

The Underside of a Fern Frond

Sorus

Sporangia

Slide 29

Life Cycle of Ferns

Fern Life Cycle

Young gametophyte (N)

Mature gametophyte (N)

Egg

Archegonium

Sperm

Antheridium

Spores (N)

Sporangium (2N)

Frond

Mature sporophyte (2N)

Gametophyte (N)

Sporophyte embryo (2N)

Developing sporophyte (2N)

Slide 30

Fern Gametophyte

Slide 31

Seed Plants

Slide 32

Seed Plants

Seed plants are the most dominant group of photosynthetic organisms on land.

Seed plants are divided into two groups:

Gymnosperms bear seeds directly on the surfaces of cones.

Angiosperms, or flowering plants, bear seeds within a layer of tissue that protects the seed.

Slide 33

Reproduction Free From Water

Seed plants have a life cycle that alternates between a gametophyte stage and a sporophyte stage.

They do not need water for fertilization of gametes.

Seed plants can live just about anywhere.

Slide 34