Please enable JavaScript.
Coggle requires JavaScript to display documents.
Chapter 20 (Division Bryophyte (Reproduction (sperm is called antheridia,…
Chapter 20
Division Bryophyte
inner cells are larger and have more parenchyma
stems are slim and have little tissue differentiation
outer layer is only slightly different from surrounding layers
all moss stems have leaves
the leaves don't evolve from the same structure of the stems
stem tissues are called the cortex
in a few species the stems have hair but the stomata don't occur
mosses occur in all parts of the world
perennial plants
mosses that live in cool wet places
plants are loose and more open
gamatophores grow from apical meristem
contain a prominent apical cell
leaves arranged in three rows with a midrib
leaves are only one cell thick except at midrib and along margin
cuticle only occurs on upper surface
the underside is uncuticlized, capable of absorbing water directly from rain
Water Transport
family polytrichacae
innermost cortex contains cells called hydroids
conducts water and dissolved minerals
each hydroid has a lepatoids
elongated cells that lose cytoplasm when mature
resemble sieve cells
leaves and stems form spaces like capillary beds
at the base of the stem are rhizoids
only anchor on stem
they lack chloroplast and have red walls
small multicellular trichome-like structures , this penetrates the substrate
Development
produce a protonema
this resembles filamentous algae
number of chloroplasts in each cells distinguishes
growth of a gamatophore
begins with a spore
germinates and then sends out a long slender chlorophyllous cell
perennial and can grow many buds
filamentous cells break when these mosses are collected
a tuft of gamatophores may appear to be independent plants
when they all come from a single protozoan
Reproduction
sperm is called antheridia
short stalk surrounded by the sterile cells
reproduction can occur with mixed leaves along the gametophore stem
can be clustered at the stem tip
produces gametangia
eggs called archegonia
occurs on the same gametophore in bisexual species
Sporophyte Generation
apex of sporangium differentiates as a cap-like lid
two rows of peristome teeth
teeth respond to humidity
opening the sporangium when the air is dry
bend inward when its's humid
the zygote of a moss
undergoes a transverse division at the base
cell on bottom of the archegonium develops into small bulbous tissue
most mosses are homosporous
a few have two types of spores in each of the capsule
between the foot and the sporangium is a narrow stalk called the seta
all moss structures base this basic simple structure
none are ear branched or have leaves or buds
upper cells grow by cell division
expansion into simple apical sporangium called the capsule
called columella
contains an outer layer of sterile cells
and inner layer of sterile cells
Hornworts
never contain oil bodies
100-150 named species
rarely inhabit trees or rocks
one single large chloroplast in each cell
has elaters
a single elongated cell with spring shaped walls
meristem above the foot this produces new sporangium tissues
simultaneously. being replaced
have long horn like cylinder usually 1-2 cm long
Characteristics of Non-Vascular Plants
plants that don't have vascular tissue
embryophytes
hornworts
mosses
not true mosses
spanish moss
tillandsia usneoides
both examples apart of pineapple family
all have gametangia
all have sporangia
three dimensional growth
reproductive cells
surrounded by one or several cells
composed of parenchyma cells
exclusively terrestrial
have a cuticle over much of body
internal cells
differentiate into spores or gametes
jacket of sterile cells always present
Gametophyte Generation
only in center do they become 4-5 cells
always thin
have numerous chambers
all hornworts have a symbiotic relationship with cyanobacteria
archegonia is formed from superficial cells
doesn't completely surround the egg
mucilage chambers from near the surface (upper)
then cells are loaned into the chamber grow and become antheridia
sperm cells mature and turn into chloroplasts
become orange or yellow
Embryophytes
true plants
vascular tissue made of heterotrophic tissue
planets used to reproduce amphibious
terrestrial reproduce by aquatic
without phloem in the plant
each part can grow and develop as fast as photosynthesis allows
plants can be divided into
having both vascular tissue but no seeds
spermatophytes
have vascular tissue but no seeds
vascular cryptogams
no vascular tissue and no seeds
non-vascular
bryophytes
first plants that arose
Classification of Non-Vascular Plants
Hornworts
anthocerotophya
Liverworts
hepatophyta
Mosses
bryophyte
it isn't known how closely related the 3 are
treated as 3 distinct divisions
