Download Plant diversity Chapter 22 Plants

PLANT DIVERSITY
CHAPTER 22
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 plants
Examples: chemical -—
f oul odor, bitter
taste, toxicity;
physical—
- spines, needles, broad
leaves
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 photosynthesis
2. 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 tissues
2. Seeds
3. 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. Mosses
2. Liverworts
3. Hornworts
Source:
http://commons.wiki
media.org/wiki/File:S
phagnum_-_moss__Moos_01.jpg/
Source:http://b
logs.ubc.ca/bio
logy321/?page_
id=62
Source:
http://www.bios.niu.edu/stafstrom/bios305/bios305.html
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.homeo
pathyandmore.com
/forum/viewtopic.p
hp?t=608
Source:
http://www.hubbardbrook.org/w6_tour/
herb-stop/club-moss.htm
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://www.warpedphotosbl
og.com/split-tip-fern-spores
Source:h
ttp://gar
denwink.
blogspot
.com/201
2/06/mac
ho-ferncoolsmedown.ht
Seed Plants
• Divided into 2 groups:
1. Gymnosperms – “naked seed”; seeds are on the
surface of cones
2. 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://biology.unm.edu/ccouncil/Biology_203/Sum
maries/Non-floweringPlants.htm
Source:
http://www.plantzafrica.com/pla
ntwxyz/welwitschia.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
•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)
Source:
http://www.cfkeep.org/html/stitch.php?s=54373324154293&id=77748813831945
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