Seedless plants (Chapter 25)

What is a Charophyte and how is it connected to plants?  

currently thought to share the closest common 

ancestor with land plants  

Why is sporopollenin important the evolution of land plants? 

It provides protection from the elements  

What do Charophytes have in common with plants? 

• Sporopollenin 

• Rings of cellulose-synthesizing proteins 

• Structure of flagellated sperm 

• Formation of a phragmoplast (aid in formation of the cell plate) 

What is an advantage to being an embryophyte? 

Plants retain the developing zygote inside the female gametangia, so it gets the best source of food and protection  

What role do Antheridea and Archegonia play in plants life cycles? 

Antheridia: Male Gametangia 

 Archegonia: Female Gametangia 

The main groups (phylum) of the Bryophytes

Liverworts (phylum Hepatophyta)  

Mosses (phylum Bryophyta) 

Hornworts (phylum Anthocerophyta) 

sporophyte

consists of a foot, a seta (stalk), and a sporangium, also called a capsule, which discharges spores through a peristome 

Gametophyte

Consists of Antheridia (Male Gametangia) and Archegonia (Female Gametangia) 

How do Seedless Vascular plants differ from Bryophytes?  

They have flagellated sperm and are sporophyte dominant 

Why is vascular tissue an important adaptation? 

The vascular tissue allows them to grow much taller 

Xylem

conducts most of the water and minerals and includes tube- shaped cells called tracheids. (Up) 

Phloem

has cells arranged into tubes that distribute sugars, amino acids, and other organic products. (Down)

Homosporous plant

producing one type of spore that develops into a 

bisexual gametophyte 

Heterosporous plant

All seed plants and some seedless vascular plants 

Club Mosses (Phylum Lycopodiophyta)

Quillworts (Isoetales) 

Club mosses (Lycopodiales) 

 Spike mosses (Selaginellales) 

Horsetails (Phylum Monilophyta)

Jointed Stems: Main Photosynthetic organ 

• A ring of small leaves are found at each joint (microphylls) 

• Silica collected by in the epidermal cells contributes to the stiffness of horsetail plants. 

• Rhizomes (rhizoids) anchor the plants to the ground. Modern-day horsetails are homosporous. 

Whisk Ferm (Phylum Monilophyta)

• Lack both roots and leaves 

• Called Living Fossils 

• Epiphytes 

• Dichotomous Branching 

• Three fused sporangia 

• Underground Gametophytes 

• Homosporous 

Ferns (Phylum Monilophyta)

Pterophytes (Class Polypodiopsida) 

Have Megaphylls 

Small underground gametophyte 

Most are homosporous (Sori) 

Spores travel by air 

Crozier formation 

homosporous/heterosporous? Club moss

Both

homosporous/heterosporous? Horsetails

Homosporous

homosporous/heterosporous? Whisk fern

Heterosporous

homosporous/heterosporous? Ferns

Homosporous

Why are Whisk Ferns considered living fossils?

Because they have not changed in a very long time