Bryophytes

dominant phase of bryophytes

gametophyte

Alternation of generations

gametophyte (1n) undergoes mitosis to make ____________ that contain identical genes to parent

gametes (egg and sperm)

zygote (2n) grows larger until it becomes _______________ (2n)

sporophyte

sporophyte (2n) produces __________ through meiosis (recombination)

spores

spore (1n) is a __________ unit (e.g., pollen)

dispersal

phases under gametophyte generation (haploid = 1n)

gametophyte and spore

phases under sporophyte generation (diploid = 2n)

zygote and sporophyte

spore (1n) grows bigger until it becomes a ____________(__)

gametophyte (1n)

what is it called when bryophytes cycle between gametophyte and sporophyte generations?

alternating generations

3 bryophyte divisions

mosses, liverworts, and hornworts

What do mosses, liverworts, and hornworts have in common?

1. Gametophyte = independent & dominant

2. Unbranched sporophyte = dependent on gametophyte

3. Spore = main dispersal unit (no seeds)

bryophytes are all “non-vascular,” meaning that…

they lack lignified tissues (i.e. tracheids & vessels)

Traits to know about hornworts:

1. Thalloid gametophytes only

2. Symbiotic relationship with cyanobacteria (blue-green algae)

Thalloid

flat, undifferentiated body

Traits to know about liverworts:

1. May be leafy or thalloid

2. Oil bodies

Liverwort sporophyte

translucent seta that elongates (rather than growing via cell division) after sporogenesis

capsules contain spores and open up to release them all at once

Traits to know about mosses:

1. Gametophytes = leafy only

2. Leaves = spiraled & mid-rib

3. Multiple growth forms

Sporophyte sporangium

opens via a circular lid and slowly releases spores

Capitulum

tops of sphagnum mosses have pom pom-like cluster of branches

Acrocarpous moss

Single cluster of sexual organs produced at tip of primary module of branch system

Pleurocarpous moss

One or more clusters of sexual organs produced on lateral branches (not on tip of primary branch)

capitula and pleurocarpy are apomorphies, meaning they can…

define monophyletic groups of mosses

unbranched gametophyte

a characteristic feature of bryophytes (non-vascular land plants)