Objectives:10.0 Distinguish between monocots and dicots, angiosperms and gymnosperms, and vascular and nonvascular plants.10.1 Describing the histology of roots, stems, leaves, and flowers 10.2 Recognizing chemical and physical adaptations of plantsExamples: chemical -foul odor, bitter �taste, toxicity;physical- spines, needles, broad �leaves

PLANT DIVERSITYCHAPTER 22

Plants:•Def: multicellular eukaryotes with cell walls made of cellulose

•Carry out photosynthesis using green pigments chlorophyll a and b

•MOST are autotrophs, but some are parasites or saprobes (organisms that get nutrients from decaying materials).

•Life cycles have two alternating stages:•Haploid (N) – gametophyte•Diploid (2N) – sporophyte•What is this called???

What Plants Need to Survive:1.Sunlight - for energy for

photosynthesis2.Water and minerals – water is needed

by ALL cells, and is a reactant in the process of photosynthesis

3.Gas exchange - Plants take in _________ and give off ___________.

4.Movement of water and nutrients:•Take up water through their roots, but make food in the leaves

•Specialized tissues carry water up through the plant and carry food down to all parts of the plant.

Plant Kingdom•Botanists classify plants in four groups based on:1. Water-conducting tissues2. Seeds3. Flowers

Bryophytes (Section 22-2)•Nonvascular plants – cannot transport water throughout the plant; can only obtain water by osmosis

•Depend on water for reproduction•Lack true roots – rhizoids (long, thin cells) anchor them in the ground

•Includes:1. Mosses2. Liverworts3. Hornworts

Source: http://commons.wikimedia.org/wiki/File:Sphagnum_-_moss_-_Moos_01.jpg/

Source: http://www.bios.niu.edu/stafstrom/bios305/bios305.html

Source:http://blogs.ubc.ca/biology321/?page_id=62

Seedless Vascular Plants (Section 22-3)•How do bryophytes transport water?•Vascular plants have vascular tissue to conduct water and nutrients throughout the plant:•Xylem: transports water from roots to the rest of the plant

•Phloem: transports solutions of nutrients and carbohydrates produced by photosynthesis

•The xylem, together with lignin, which makes the cell walls rigid, allows vascular plants to grow taller than nonvascular plants.

Ferns and Their Relatives•Seedless vascular plants include:•Club mosses – look like mini pine trees

•Horsetails•Ferns

Source: http://www.hubbardbrook.org/w6_tour/herb-stop/club-moss.htm

Source: http://www.homeopathyandmore.com/forum/viewtopic.php?t=608

Ferns•What is alternation of generations?

•The fern plant we are used to seeing is actually a diploid sporophyte.

•Fern sporophytes develop haploid spores on the underside of their fronds.

Source:http://gardenwink.blogspot.com/2012/06/macho-fern-cools-me-down.html

Source: http://www.warpedphotosblog.com/split-tip-fern-spores

Seed Plants• Divided into 2 groups:1.Gymnosperms – “naked seed”; seeds are

on the surface of cones2.Angiosperms – “enclosed seed”; flowering

plants• Do not require water for reproduction

to occur; can transfer sperm (pollen grains) by pollination (transfer of pollen – the male gametophyte – from male reproductive structures to female reproductive structures)

• Seeds are just fertilized plant embryos, surrounded by a protective seed coat.

Gymnosperms – Cone Bearers•Includes:• Gnetophytes• Cycads – palm-like plants with large cones• Ginkgoes – only one species (Ginkgo biloba)

• Conifers – pines, spruces, firs, cedars, sequoias, redwoods, junipers

Source: http://www.plantzafrica.com/plantwxyz/welwitschia.htm

Source: http://biology.unm.edu/ccouncil/Biology_203/Summaries/Non-floweringPlants.htm

Angiosperms – Flowering Plants•Flowers are reproductive organs which contain ovaries that surround and protect the seeds.

•Fruit is just a wall of tissue around the seed.

•Very diverse group:•Monocots and dicots•Woody and herbaceous•Annuals, biennials, and perennials

Monocots vs. Dicots

Source: http://www.cfkeep.org/html/stitch.php?s=54373324154293&id=77748813831945

• Cotyledon: the first leaf or pair of leaves produced by a seed plant.

(“seed leaf”)• Also differ in roots:• Monocots – fibrous roots

• Dicots – tap roots (like carrots)

Woody/Herbaceous Plants; Annuals, Biennials, and Perennials

•Woody plants: trees, shrubs, and vines•Herbaceous plants: •Stems are smooth and nonwoody• Includes most flowers

•Annuals: go from seed, to plant, to dying in one growing season

•Biennials: life cycle takes 2 years•1st year: seed germinates, roots and short stems develop

•2nd year: stems, leaves, and flowers grow, and plant dies

•Perinneals: live for many years