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

Ferns mosses

Conifers angiospermsGreen algea

Terrestrial

Embryo (young dormant sporophyte)

Dominant sporophyteVascular system with tracheids

seedsSecondary growth

Flowers

Vascular plants

Seed plants

Land plants* Plantsphotosynthetic eukaryotes that uses chlorophylls, store carbohydrates, usually as starch, and develop from embryo protected by tissues of the parent plant (embryophytes).* Plant life cycle

Norganism

2Norganism

mitosis gametes

zygote

syngamy

meiosisspores

mitosissporophyte

gametophyte

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 tracheids2- sporophyte phase is dominant3- seeds which is embryos protected in a seed coat and supplied with additional nutrition4- 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

Ferns1- 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 pith2-the rigid tracheid cell gives support in addition to water conductance3-well developed root underground stem, rhizome4-true leaves fronds (P.109)Not homologous to leaves of mosses 5-heart sheped gametophyte, prothallus6- 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