Seedless Reproduction

Unit 7 – Lesson 2 Notes

Seedless Reproduction

• Seedless plants – plants that do not produce seeds. They include all nonvascular and some vascular plants.

• Millions of years ago, most plants on Earth were vascular seedless plants

Vascular means VEINS!

Nonvascular vs. Vascular• Nonvascular plants – plants that do not have

structures that transport water and substances throughout the plant. Instead water and substances simply move from cell to cell.

Nonvascular vs. Vascular

• Vascular plants – plants that have tubelike cells (called the xylem and phloem) that transport water and substances throughout the plant.

Nonvascular/Vascular Seedless Plants

• Nonvascular Examples

AlgaeMoss

• Vascular Example

Ferns

All About Algae

• Is algae good or bad?

• What are we using algae for in today’s society?

Oligotrophic Lake Eutrophic Lake

Nonvascular Seedless Plants

• The Moss Cycle – Moss plants have a life cycle that illustrates typical sexual reproduction in nonvascular seedless plants.

Zygote (2n)

Gametophyte (n)

Sex Cells (n)

Vascular Seedless Plants

• Most vascular seedless plants are ferns.

Vascular Seedless Plants– Fern sporophyte plants have

fronds that grow from an underground stem called a rhizome.

– Fern spores are produced in sori, which are usually on the underside of fronds.

– A fern spore that lands in a favorable environment grows into a gametophyte plant called a prothallus.

Vascular Seedless Plants

– Sex cells form in the prothallus.

– When fertilization occurs, the zygote starts the sporophyte stage.

– Ferns may reproduce asexually when rhizomes form new branches and are separated from the main plant.

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A. Meiosis takes place to produce thousands of spores.

B. Spores are ejected. They grow into a gametophyte plant.

Sporophyte Gametophyte

C. The prothallus contains the male and female reproductive structures.

D. Water is needed for the sperm to swim to the egg. Fertilization occurs and a zygote is produced.

E. The zygote is the beginning of the sporophyte stage and grows into the familiar fern plant.