Vascular Plants
Moving to Land
Overtime, 500 millions of years ago, plants on
Earth evolved from aquatic to terrestrial
environments
What are some problems to overcome?
Material transport
Structure/support
Desiccation
Gas exchange
Benefits to moving to land
easier access to sunlight for photosynthesis,
continuous free movement of carbon dioxide
and oxygen
Vascular Plant Organs
Roots,
stems and
leaves
Vascular Plant Organs
Roots – Absorb water and dissolved
nutrients from soil
Anchor plants – in the soil and
prevent them from being knocked
down by wind
Storage – site for food storage
Vascular Plant Organs
Stems – Support - hold leaves up towards
the sun for optimal exposure
for photosynthesis
Transport – between roots and
leaves (via vascular tissue,
phloem and xylem
Storage – site for food storage
Vascular Plant Organ
Leaves – Photosynthesis and Cellular
respiration
Formulas????
Modified to reduce transpiration
Cuticle and pores
Vascular Tissues
http://www.harcourtschool.com/activity/vascul
ar/vascular.html
Vascular Plant Tissues
XYLEM– Carries water
and dissolved nutrients
from the soil, from the
roots, into the stem and
into the leaves.
• It forms a continuous set
of tubes that stretch from
the roots to the leaves
Vascular Plant Tissue
PHLOEM– Distributes
food made in the leaves
throughout the plant.
• The glucose produced by
photosynthesis in the
leaves, moves down
towards the roots.
Questions
• The direction of glucose transport can be
reversed in situations when the glucose levels
in the roots are greater than in the leaves.
• In which situations might this occur?
Vascular Tissues
Vascular Plants
10 phyla
Includes:1) seedless vascular plants (ie. ferns)
2) plants with unprotected seeds
(ie. Cone-bearing plants)
3) flowering plants
Similarities with mosses
1) free-living gametophyte
2) no seeds
3) mobile sperm that require water for
fertilization
Differences from mosses
1) a vascular system which transports water,
nutrients and photosynthetic products around
the plant,
2) sporophytes as the dominant life stage
3) stomata
Fern
Most diverse group of plants
Most abundant after flowering plants
Alternation of generation between gametophyte
(haploid) and sporophyte (diploid)
Fern Life Cycle
http://trc.ucdavis.edu/biosci10v/bis10v/media/
ch15/fern_life_cycle_v2.html
Takes notes from fig 10.7
Fern Life Cycle
-gametophyte (n) makes
gametes sperm (n) and egg
(n)
-gametes fuse when
mature, fertilization
-zygote (2n) develops
attached to gametophyte
(n)
-zygote becomes spore-
bearing sporophytes (2n)
-spores (n) disperse and
develop into
gametophytes(n)
Fern Sporophyte
-large leaves are called fronds
-fronds contain spores on the
underside, contained in a sac called
sporangia
-sporangia cluster together to form
a sori
Fern Gametophyte
Young sporophyte growing out of a gametophyte
Sori containing clusters of sporangia
Grape-looking structures are individual
sporangium
Video of sporagnium releasing
spores