Biol 112 Chapter 25 Seedless Plants

Archaeplastida

Plant supergroup

Charophytes

Closest protist to plants

Desiccation

Drying out

Lignin

Provides structural support to vascular plants

Alternation of generations

Life cycle of a plant where they have a 2n and n multicellular form

Gametophyte (n) → mitosis→ gametes → Sporophyte (2n) → meiosis → Spores

Alternation of generations

Sporopollenin

Protective layer on haploid spores that help it travel through the air

Gametangia

Reproductive organ in nonvascular seedless plants

Antheridium

Male gametangia

Water

What is required for reproduction of seedless plants?

Flagellated sperm

Trait unique to seedless plant sperm

Archegonium

Female Gametangia

Apical Meristem

Continuously dividing cells to create shoots and root

Waxy cutitcles

Prevents desiccation with controllable stomata

Secondary metabolites

Chemicals that deter, repel, or poison competitors, herbivores, and parasites

Mycorrhizae

Mutualism with fungi predating true roots

Bryophytes

Seedless nonvascular plants

Rhizoids

“roots” in bryophytes (not true roots)

Gametophyte

Dominant form in bryophytes

Dependent on gametophyte

How do sporophytes live in bryophytes

Liverworts

Bryophytes with elevated gametophytes that resemble tiny trees

Hornworts

Bryophytes with horn-like tapered shape of sporophyte

Mosses

Most numerous bryophyte in extreme environments, helping to pioneer nutrient-poor soil

SVP

Seedless vascular plants

Sporophyte

Dominant form in SVP

Xylem

Transports water

Phloem

Transports nutrients

Microphylls

Unbranched vascular tissue only in lycophytes

Macrophylls

Branched vascular tissue in all other vascular plants

Sporophyll

Leaves modified to bear sporangia

Sori

Sporangia on ferns

Strobilus

Sporangia on lycophytes

Homosporous spores

Only 1 type of spore is produced, creating bisexual gametophyte (SVP)

Heterosporous spores

Produces Megaspores (female gametophyte) and microspores (male gametophyte) (Seed plants)

Lycophytes

Club moss in tropical and temperate environments

Pterophytes

Ferns and such