Chapter 27 Nonvascular and Seedless Vascular Plants Part 2

Bryophytes are what?

simple land plants (moss, liverwort, hornwort) that do not have vascular tissue, so they stay small and close to moisture

Why are bryophytes small?

they have no vascular tissue (no xylem/phloem), so they can’t move water far and can’t grow tall

Do bryophytes have roots?

no → they have rhizoids, which only anchor them and are not true roots

Which stage is dominant in bryophytes?

gametophyte (n) → the green moss you see; it is the main plant body

What does the gametophyte do?

produces sperm and egg (gametes) for reproduction

What does the sporophyte do?

produces spores (n) by meiosis and stays attached to the gametophyte in bryophytes

Why do bryophytes need water?

because sperm must swim to the egg for fertilization

What is fertilization?

sperm (n) + egg (n) → zygote (2n), combining DNA

What is meiosis?

process that cuts DNA from 2n to n so the life cycle can return to the haploid stage

What are spores?

haploid cells (n) made by the sporophyte that grow into a new gametophyte

haploid cells (n) made by the sporophyte that grow into a new gametophyte

plants with transport tissue (xylem and phloem) that move water and food, allowing them to grow larger

What does xylem do?

moves water and minerals upward and contains lignin for support

What does phloem do

moves sugars (food) throughout the plant

What is a cuticle?

a waxy coating on the plant surface that prevents water loss

What are stomata?

small openings that allow gas exchange (CO₂ in, O₂ out) and control water loss

What are seedless vascular plants?

plants that have vascular tissue but still reproduce with spores, not seeds

Example of seedless vascular plants?

ferns (most important), plus horsetails and whisk ferns

Where do ferns make spores?

in sporangia located in clusters (sori) on the underside of leaves

What grows from fern spores?

a small gametophyte (n) that makes sperm and egg

What are giant lycophytes?

ancient tree-like plants that lived in swamps and later formed coal deposits

What are seed plants?

most advanced plants that reproduce using seeds and pollen instead of spores

Why don’t seed plants need water?

because pollen carries sperm through the air, so sperm does not need to swim

What is pollen?

structure that contains the male gametophyte and transports sperm

What is an ovule?

structure that contains the egg and becomes a seed after fertilization

What is a seed?

a structure that protects the embryo and stores food for growth

Gametophyte vs Sporophyte?

gametophyte (n) → makes gametes
sporophyte (2n) → makes spores

Why is meiosis important?

it reduces DNA from 2n to n so the life cycle can continue without doubling DNA each generation

biggest differences between plant groups?

bryophytes → no vascular tissue, spores, gametophyte dominant
ferns → vascular tissue, spores, sporophyte dominant
seed plants → vascular tissue, seeds + pollen