Transcript The Land Plants: Adaptation for Terrestrial life

The Land Plants: Adaptation for
Terrestrial life
Announcements
• There will be a quiz next lab period
• Assigment for this lab include page 113,
114, 115,116, 117, 118
This Lab
•Land plants
•Mosses
•Ferns
•Conifers
•Angiosperms
•Dissecting Cassia and Lily
Land plants
Vascular plants
Seed plants
Green algea
Conifers
angiosperms
Ferns
Flowers
mosses
Secondary growth
seeds
Vascular system with tracheids
Dominant sporophyte
Embryo (young dormant sporophyte)
Terrestrial
Land plants
* Plants
photosynthetic eukaryotes that uses chlorophylls, store
carbohydrates, usually as starch, and develop from
embryo protected by tissues of the parent plant
(embryophytes).
* Plant life cycle
N
organism
mitosis gametes
gametophyte
syngamy
mitosis
sporophyte
spores
meiosis
2N
organism
zygote
Land plants
* 12 phyla exist
nontracheophytes (nonvascular or bryophytes)
1-The persistent generation is the gametophyte (dominant)
2-Sporophytes are very short-lived, are attached to and
nutritionally dependent on their gametophytes and
consist of only an unbranched stalk, or seta, and a single,
terminal sporangium
3-bryophytes never form xylem tissue, the special
lignin-containing, water-conducting tissue that is found
in the sporophytes of all vascular plants
Nontracheophytes
1- Mosses
*hydroids for water and leptoids for nutrient
*dependance on water for sexual reproduction
*Antheridia (sperm producing structures) and
Archegonia (egg producing structures)at the apex of
gametophyte
*calyptra is the enlaged archegonium containing the
zygot
*sporophyte is composed of foot, stalk (seta) and
sporangium (spores containing capsule)
*germinating spore grow into young gametophyte
(protonema)
Mosses
Mosses
Nontrcheophytes
2- Hornworts
3- liverworts
Trcheophytes
1- vascular system with tracheids
2- sporophyte phase is dominant
3- seeds which is embryos protected in a seed coat and
supplied with additional nutrition
4- secondary growth in a ring around stems
(shoot meristems) and roots (root meristems)
with the production of wood (shoot meristems)
Vascular system
* It is plant tissue consisting of cells joined into tubes that
transport water and nutrients throughout the plant
body (in all but bryophytes).
*xylem is the tube-shaped, nonliving portion of the vascular
system in plants that carries water and minerals from the
roots to the rest of the plant.
*Phloem is the portion of the vascular system in plants
consisting of living cells arranged into elongated tubes that
transport sugar and other organic nutrients throughout the
plant
Ferns
1- you can recognize 4 tissue type in the vascular system
thick outer cortex
thick walled cells of xylem tissue made up of tracheids
thin walled cells of phloem tissue
inner pith
2-the rigid tracheid cell gives support in addition to
water conductance
3-well developed root
underground stem, rhizome
4-true leaves fronds (P.109)
Not homologous to leaves of mosses
5-heart sheped gametophyte,
prothallus
6- cluster of sporangia on under surface of fronds,
sorus
Ferns
Ferns
gametophyte stage of
a fern with rhizoids
Cross section of a
fern stem (stained)
Conifers
•Pines (F.29.5)
male and female (fertilized) cones
sporangium is surrounded by integument
naked seeds which is the mature ovule
secondary growth (wood or secondary xylem)
Angiosperms
•Flowering plants
•Pollinators
•Seed, embryo, endosperm and seed coat (P.110)
-embryo: 2n, sperm nucleus and egg
-endosperm: 3n, sperm nucleus and and 2 central nuclei
-seed coat: 2 integument
•Sepals and petals: modified leaf appendages
•stamens: modified male structure
•Carples: enclose the ovules
•fruit:mature carpels including the seeds
•pistil: femal structure
•receptacle: region of attachement
Angiosperms
Angiosperms
*Monocots (palms, orchids, lilies, grasses)
one embryonic cotyledon
flower parts are in multiples of three
parallel veins
*Dicots (trees, herbs, cacti, soyabeans, sunflowers)
two embryonic cotyledons
flower part are in multiple of five
netlike veins
Angiosperms
Angiosperms
Angiosperms