How do we classify and group plants? What are the major divisions? How are they grouped and classified? How do you use a plant identification key?

Plant Taxonomy Nonvascular Plants- have small reduced leaves, no vascular tissue( veins) no true roots, and reproduce by spores or flagellated cells that travel through water.

Vascular Plants- have true roots, stems, and leaves with vascular tissue. Xylem- water and minerals. Phloem- transports carbohydrates

Plant Divisions nonvascular Bryophyta- mosses vascular seedless Lycophyta-club moss Pterophyta-Ferns seed plants Gymnosperms-naked seeds Angiosperms-flowering plants

Gymnosperm Coniferophyta- needle or scale leaf, cones ( conifer) Anthophyta or Angiosperm Monocots- parallel veins, petals in 3’s Dicots- net veins, petals in 4’s or 5’s

Bryotphytes Mosses

Moses Non-vascular Plants- No tissues to carry water Spores used for reproduction No true roots, stem Reduced leaves

Liverworts

sporophyte gametophyte Mosses

sporophyte gametophyte

In mosses the dominant stage of their life cycle they only have half of their total chromosme number.

Spore Producing Spores are reproductive stages that have only half the chromosomes or genetic material.

VASCULAR PLANTS

Lycopodium, Lycophyta

Pterophyta Ferns- reproduce with spores but have veins to carry water

Gymnosperms Naked seeds or seeds produced in cones.

Angiosperms or Anthophyta Flowering plants Seeds produced within a fleshy fruit with gametes borne within a flower.

Antheridium Archegonium

Liliacea

Taxonomy key\identification key You always have two choices in a description of the organisms characteristic Choose the correct choice and it takes you to a name or a number.

dicot

monocot

Opposite Leaf arrangement

Alternate leaf arrangement

Botany Tissues, Organs, and Systems

Vascular Tissue Xylem (wood) trachieds and vessel elements make up xylem. They are nonliving tubes with openings at the ends to carry water.

Transport in Vascular Plants Water and minerals begin movement by osmosis. through root and root hair

Transport in Plants cont. capillary action in xylem vessel element Adhesion-water vessel wall Cohesion- water to water

Transpiration- water moves out through stoma in the leaf. closed H2OH2O

Loss of Turgor Turgor

Phloem carries carbohydrates sieve tube elements-- connected by sieve plates

Heart wood Spring wood Summer Wood Vascular cambium phloem Cork cambium CORK Phloem rays

Vascular Tissue Xylem- wood, carries water Spring wood- larger openings smaller ring Summer wood – more compact rigs are wider Phloem- carries sugar phloem rays carry back and forth

Growth Tissue Vascular Cambium- grows new xylem to the inside and phloem to the outside Cork cambium- grows new cork to the outside BARK- is vascular cambium, phloem, cork cambium, and cork

xylem phloem Cortex ( storage, support) (7,8) 11 4 & 5

Merristematic Regions Apical Bud Root Tips

Leaf Primordia Apical Meristem Axillary Bud

Roots primary secondary TAP DIFFUSE

Germination Seeds begin to grow as a result of cell division using much oxygen seeds need warm temperatures, water, and oxygen to germinate but the seed supplies the food.

hypocotyl

Embryonic Tissue Seed leaves of an embryo Below the cotyledon Above the cotyledon Embryonic root

cap merristematic Elongation maturation

Leaves- the main photosynthetic parts of a plant Types of Simple Compound Pinnate Palmate

Leaf Cross Section Epidermis- prevents water loss protects from UV light Palisades- photosynthesis zone ( contains much chlorophyll) Mesophyll ( spongy layer)- storage of gases, water and sugar Veins – contain xylem and phloem

Abscision layer- cuts base of leaf off during defoliation

Stomate Stomate- leaf opening for gas exchange and water loss Guard Cells- control opening of stomate Stoma - opening

Photosynthesis CO 2 +H 2 O light C n H 2n 0n+O 2 Light- measured as an absorption spectrum, the wavelengths that are most important are different for different types of autotrophs

Photosyntheis Plant takes in carbon dioxide\ Plant takes up water Plant produces sugars Plant gives off oxygen

petiole Margin (serrate) Pinnate veins

Simple Leaf with Entire Margin and Pinnate Veins

Angiosperms or Anthophyta Flowering plants Seeds produced within a fleshy fruit with gametes borne within a flower.

Perfect Flower

STAMEN- male part of flower Filament Anther

stigma style ovary 3n 2n Zygote is 2n Endosperm -food for development 3n Pollen tube Ovules within the ovary contain an embryo PISTIL or CARPEL

Composite Family

Flower Structures Stamen- male floral part Anther- produces pollen ( n) haploid Filament- stalk that supports stamen

Floral Parts Pistil- female floral part Style- stalk that supports stigma Stigma- sticky part attracts pollen Ovary- eggs develop and are fertilized to become seeds

Plant Response to Light –Photoperiodism LONG DAY_ require 12 hr. daylight or more to flower SHORT DAY-require less than 12 hr daylight DAY NEUTRAL – flower according to maturity not light

Plant Hormones Alter cell division Increase elongation Regulate gene activity

Auxins

Plant Auxin on Agar Block

Auxin Mutants