Chapter 25 - Seedless Plants

What do Chlorophytes, Charophytes, and Plants have in common?

• Multicellular

• cell walls made of cellulose

• Chloroplasts with same pigments(chlorophyll)

• Storage molecule is starch

Why did algae move from oceans to shallow lakes?

More resources and less competition

What was an important adaptation that green algae was subjected to?

Periodic dehydration(when lakes dried out)

What were advantages of land(for algae)?

CO₂ higher, light intensity is higher, more minerals, no “herbivores”, no competition

What was a constant danger for algae when they moved from water to land?

Desiccation(drying out)

Both gametes and zygotes must be protected from desiccation

What are derived characteristics from plants?

1. Alternation of generations(1n and 2n are multicellular)

2. Walled haploid spores

3. Apical Meristem-where most of growth happens

4. Evolution of waxy cuticle to resist desiccation(keeps from drying out)

5. Mycorrhizae

6. Cell walls with Lignin(unique to plants)

Walled haploid spores

dispersal through air: sporopollenin protects (made within multicellular sporangium

Multicellular gametangia

protects sperm within antheridium(male)

Eggs protected within Archegonium

fertilization here: forms zygote(female)

Apical meristems have continuously dividing cells

True

in the apical meristem of the root it shoots towards sunlight and grows towards resources

True

What is the function of the waxy cuticle?

The waxy coat stops dissecation

How do the pores in the plant allow for the CO₂ and O₂ exchange?

The stomata controls in most plants

What are secondary metabolites?

chemicals that deter, repel or poison competitors,

herbivores, & parasites

Mycorrhizae

mutualism with fungi; helps water & mineral absorption

• dates back to first land plants (before true roots)!

What are Bryophytes?

seedless nonvascular plants

What do bryophytes require for reproduction?

Water

What do bryophytes have instead of true roots?

Rhizoids(attachment)

How many Phyla are in Bryophytes?

3

What Phyla belong to Bryophytes

• Liverworts

• Hornworts

• Mosses

What is the scientific name for Liverworts?

Marchantiophyta

What is the scientific name for Hornworts?

Anthocerotophyta

What is the scientific name for Mosses?

Bryophyta

What ploidy is dominant for the gametophyte generation in bryophyte?

Haploid

What does dominant mean?

Longest lasting or largest

What in Bryophytes make/release haploid spores?

Sporangium

What does the bryophyte gametophyte make?

eggs and flagellated sperm

Where does the diploid sporophyte grow?

Grows within the Archegonium of the gametophyte

What generation is A? 

Sporophyte

What ploidy is generation A?

Diploid

What generation is B?

Gametophyte

What ploidy is B?

Haploid

What is Sphagnum “peat moss” bogs used for?

harvested for fuel; important for wetlands

How old is the oldest seedless vascular plant fossil?

450 Million years old

Xylem

cells specialized to move water and minerals

Phloem

cells specialized to move sugars, amino acids, other organic products

What only contains Microphyll

Lycophytes

What are microphylls

Small, spine-shaped leaves supported by a single

strand of vascular tissue

Are microphyll leaves unbranched or branched vascular tissue

unbranched vascular tissue

Almost all other vascular plants have megaphylls

True

Which have greater photosynthetic productivity(more surface area) microphylls or megaphylls

Megaphylls

What are Sporophylls?

Leaves modified to bear sporangia

Fern sporophylls look like normal leaves but have

sori that generate spores on underside

True

What are Strobilus

Lycophyte sporophylls that are modified into a cone-like structure

Lycophytes

Club mosses(spike moss and quillwort)

Monilophytes

Whisk ferns, horsetails, ferns

Whisk ferns

have vascular tissue, no true leaves or true roots, homosporous, and dichotomous branching.

Horsetails

Contain Strobilus, homosporous, photosynthesis occur in the stem, and jointed stems with tiny leaves

Ferns

Most widespread and diverse monilophytes, large megaphylls, sori on underside of sporophylls, and can be epiphytes.

What are epiphytes?

grows on the surface of a plant

What are Seedless Vascular Plant characteristics?

1. Branched sporophytes that are

independent of gametophyte for nutrition

2. Diploid sporophyte dominates life cycle

3. Transport in Xylem and Phloem (vascular

system)

• Xylem: cells specialized to move water

and minerals

• Phloem: cells specialized to move

sugars, amino acids, other organic

products

4. Evolution of true roots

5. Evolution of true leaves