Transcript seed plants

Seed Plants
Gymnosperms &
Angiosperms
1
Evolution Of Land Plants
REMEMBER:
• Terrestrial plants evolved from a
green algal ancestor
• The earliest land plants were
nonvascular, spore producers
(bryophytes)
• Ferns were the 1st vascular, spore
producing plants
• Gymnosperms & angiosperms were
the 1st vascular, seed plants
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3
Characteristics of Seed Plants
• Multicellular
• Autotrophic
• Alternation of
Generations
• Reproduce by Seeds
• Vascular tissue for
transport
• Heterosporous –
make female
megaspores & male
microspores
4
Dandelion dispersing seeds
Reasons for Success on Land
• Waxy cuticle
• Stomata with guard cells to open &
close
• Gametes protected in tissue called
Gametangia
• Pollen tube to transfer sperm to the
egg instead of water
• Seeds protect developing embryo &
contain food
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Seeds and Fruits
6
Seeds
• Seeds contain a young,
developing plant embryo
• Seeds are covered with a
protective seed coat (testa)
• Inside is stored food or
endosperm that the young
plant uses as it begins to
sprout or germinate
• Seeds form from ripened
ovules after fertilization
7
Parts of a Seed Embryo
• Primary root or Radicle
• One or two embryonic leaves called
Cotyledons
• Plumule becomes the shoot
• Stem like portion below cotyledons
called Hypocotyl
• Stem like portion above cotyledons
called Epicotyl
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Parts of a Seed
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10
Endosperm (3n)
Seed Coat
Cotyledon
Plumule
Epicotyl
Hypocotyl
Radicle
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Seed Dispersal
• Seeds must be
scattered (dispersed)
away from the parent
plant
• Testa (seed coats)
may last thousands of
years
• Seeds eaten by
animals aren’t digested
but pass out with
wastes
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Seed Dispersal
• Seeds may have adaptations such as
stickers, hooks, or fuzz to adhere
to animals
13
Seed Dispersal
• Both water and
wind can scatter
seeds
Wind
Dispersal
Water Dispersal
14
Seed Germination
• Early growth of
plant embryo
• Begins when seed
absorbs water &
breaks seed coat
(testa)
• Embryo uses stored
food of cotyledons
to begin growing
15
Fruits
• Form when ovary with ovules (eggs)
ripens
• May be dry and hardened (nuts)
• May be enlarged and fleshy
(berries, apples, tomatoes)
• Used to help disperse seeds
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Types of Fruits
• Simple fruits – form from a
single ovary (apple)
• Aggregate fruits – forms from
several ovaries of the same
flower (blackberry)
• Multiple fruit – forms from
several ovaries of different
flowers (inflorescence)
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Plants with Vascular
Tissue
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Taxonomy of Vascular Seed
Plants
• Phylum Gnetophyta: Ephedra,
Gnetum
• Phylum Cycadophyta: Cycads
• Phylum Ginkgophyta: Ginkgo
• Phylum Coniferophyta:
Conifers
• Phylum Anthophyta: Flowering
plants
gymnosperrms
angiosperms
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Sporophyte
microsporangium megasporangiumx
microspores megasporesx
microgametophyte megagametophytex
antheridium archegonium
lsperm eggmm
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Seed plants (Ch.30)
Tiny gametophytes protected in ovules and pollen grains
Advantages of seeds
Gymnosperms have “naked seeds”
Angiosperms have seeds in fruits
Monocots
Eudicots
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12: Gymnosperms and
Angiosperms
• Gymnosperm
– Intro and evolution
– Life cycle and
reproduction
– Uses and significance
• Angiosperms:
Flowering plants
– Intro and evolution
– Life cycle and
reproduction
– Uses and significance
– Monocots vs. dicots
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Kingdom Plantae
• Evolutionary tree of plants
• From primitive more advanced
traits
Bryophytes
_______
Gymnosperms
__________
Flowers
________
Green
alga
ancestor
Vascular 
Terrestrial 
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GYMNOSPERMS
• Introduction – Gymnosperm means “naked
seed” (From the Greek: gymnos = naked;
sperm = seed)
• More advanced than ferns – do not have
spores, they have seeds.
• The seeds of the gymnosperms lack a
protective enclosure (unlike flowering
plants which have flowers and fruit).
• Examples of gymnosperms:
• Conifers (pine trees), cycads,
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ginkgo biloba
Evolution of gymnosperms
• Gymnosperms evolved from fern-like
ancestors
• Advancements of gymnosperms over ferns:
• 1. Seed (plant embryo, food storage tissue,
and seed coat)
• 2. Gymnosperms do not depend on water for
fertilization (have air-borne pollen)
• 3. Have a more dominant sporophyte
generation
• 4. Have a more efficient vascular system
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• Exhibits alternation of generations
• Sporophyte generation (2n) is dominant
• Gametophyte generation (1n) is contained in and
dependent on the sporophyte generation
Gymnosperm life cycle
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Gymnosperm
lifecycle
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Sporophyte generation
• Sporophyte produces two types of spores
(heterosporous)
• Megasporangium – undergoes
meiosis to produce megaspores
(female gametophyte)
• sporangium – undergoes
meiosis to produce haploid microspores,
germinate to produce male gametophyte
(pollen)
• Many gymnosperms use wind
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for pollination and seed dispersal
Wood produced by
gymnosperms
• Gymnosperms have a very efficient and
effective vascular system
• Usually woody plants
• Xylem  wood of a tree
• Phloem  bark of the tree
• Wood is formed
from secondary growth
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Primary vs. secondary
growth
• 1. Primary growth – occurs in
apical meristems of shoots and roots
• Results in increase in length
• 2. Secondary growth – derived
from secondary or lateral meristems
• Results in increase in girth (width)
• Common in trees (wood and bark)
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Secondary growth
• The cambium forms secondary xylem and
secondary phloem
• Wood – is secondary xylem; cells are dead
at maturity and only cell wall remains
• Bark – is secondary phloem (conducts food)
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Annual rings
• Annual rings – xylem formed by the
vascular cambium during one growth season
• Early Spring wood – vessel diameter is
large, xylem walls are thinner
• Late Summer wood – vessel diameter is
small, walls are thicker
• Tropical trees:
have no annual
rings, because
seasons are so
similar
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Vascular tissue: Trees
• Vascular tissue is located on the
outer layers of the tree.
bark
_______
Vascular
cambium
wood
________
copyright cmassengale
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Gymnosperms
• Conifers are most important group of
gymnosperms
• Largest and most familiar group
• Bare seeds in cones
• Staminate cones – male cones
• Ovulate cones – _________ cones
• Seeds produced on an open scale
• (Do not produce flowers
or fruit)
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Gymnosperms
• Mainly woody plants that include
• Oldest living trees: bristlecone pine,
5000 yrs old!
• Most massive trees
(giant sequoia):
up to 375 ft. tall,
41 ft wide!
• Tallest living trees (redwoods)
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Conifers
• Conifers adapted to temperate to cold
regions
• Narrow leaves (needles) help to conserve
water
• Covered by resins – for protection from
predators, fire, etc.
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Other gymnosperms
• Cycads – short shrubs,
native to tropical regions
(look like palms)
• Ginkgo biloba –
a “living fossil”,
male and female tree,
used as a medicinal plant
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Other gymnosperms
• Welwitschia – a bizarre gymnosperm plant that grows
in Namib desert (So. Africa).
• Live up to 2000 years in these extreme conditions!
• Only makes two leaves throughout its life. It takes
water from sea mist
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Significance of gymnosperms
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Ecological importance:
Provide food and habitat for wildlife
Forests prevent soil erosion
Reduce greenhouse-effect gasses
Economic and commercial importance:
Lumber for wood, paper, etc.
Resins – wood, furniture, etc.
Ornamental plants (trees, landscaping)
Food – pine nuts (pesto, etc.)
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ANGIOSPERMS
•
•
•
•
Angiosperm means “covered seed”
Have flowers
Have fruits with seeds
Live everywhere – dominant plants in the
world
• 260,000 species (88% of Plant Kingdom)
• Angiosperms are the most successful and
advanced plants on earth
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Evolution of Angiosperms
• Advancements over gymnosperms:
• Angiosperms have flowers – many use
pollinators
• Fruits and seeds – adapted for dispersal
• Double fertilization of the endosperm in
the seed
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Angiosperm life cycle
• Flower has male and female sex
organs
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Flower structure
• Male sex organs: Stamens, composed of anther –
organ that produces pollen (male gametophyte)
• Female sex organs: The carpel
• Ovary is the enlarged basal portion of carpel
that contains the ovules (female gametophyte)
• The stigma is the
receptive portion of
the carpel for pollen
grains to adhere
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Flower structure
• Non-reproductive parts:
• Sepals (green) are the
outermost whorl of
leaf-like bracts
• Petals (usually colored)
are the inner whorl of
leaf-like bracts
• Both can have various
shapes and colors
• Tepals _______________
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Angiosperm life cycle
• Heterosporous: forms two different
types of spores (micro- and megaspores;
male and female spores)
• Male – pollen grains contain tube nucleus
and generative cell (2 sperm nuclei)
• Female – female gametophyte contains
egg and 2 polar nuclei
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Angiosper
m
lifecycle
Flowering plants exhibit
alternation of
generations. The large,
familiar flowering plant
is the diploid
sporophyte, while the
haploid gametophyte
stages are microscopic.
The unique feature
about the life cycle of
flowering plants is a
double fertilization that
produces a diploid
zygote and a triploid
endosperm or nutritive
tissue.
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Double fertilization
• Pollen grain germinates on stigma forming a
pollen tube, which grows down style to the
ovary
• Pollen has 2 haploid sperm nuclei, which
travel to the ovary
• One sperm nucleus fertilizes the haploid
egg forming the 2n zygote
• Another sperm nucleus unites with the 2
polar nuclei, forming the triploid (3n)
endosperm
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Seeds
• Fertilized egg grows into a
___________, which grows into plant
embryo
• Endosperm is stored food tissue – for
the embryo to grow
• Mature ovule becomes the seed coat
and/or fruit
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Monocot vs. dicot
• Angiosperms are divided into monocots
and dicots
• As the zygote grows into the embryo,
the first leaves of the young sporophyte
develop and are called as cotyledons
(seed leaves)
• Monocots have one cotyledon (corn, lily,
etc).
• Dicots have two cotyledons (bean, oak,
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etc).
Comparing monocot vs. dicot
plants
FEATURE
MONOCOTS
DICOTS
Cotyledons
1
2
Leaf venation
parallel
broad
Root system
Fibrous
Tap
Number of
floral parts
Vascular
bundle
position
Woody or
herbaceous
In 3’s
In 4’s or 5’s
Scattered
Arranged in a
circle
Herbaceous
Either
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Monocot vs. dicot
• Number of cotyledons: one vs. two
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Monocot vs. dicot
• Leaf venation pattern:
• Monocot is parallel
• Dicot is net pattern
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Monocot vs. dicot root
• Monocot: Fibrous root
• Dicot: Tap root
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Monocot vs. dicot
• Flower parts:
• Monocot: in groups of three
• Dicot: in groups of four or five
copyright cmassengale
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Monocot vs. dicot
• Vascular bundle position:
• Monocot: _____________
• Dicot: arranged in a circle
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Monocot vs. dicot
• Stem type:
• Monocot: Herbaceous
• Dicot: herbaceous or woody
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Summary: Monocot vs. dicot
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Seed plants (Ch.30)
protected gametophytes
advantages of seeds
gymnosperms
angiosperms
monocots
eudicots
Fig. 30.2 Notice how
the importance of the
gametophypte
dwindles as we
move from mosses
to ferns to seed
plants. The
gametophyte of a
seed plant is
microscopic and not
green (does not
carry out
photosynthesis)
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Seed plants (Ch.30)
protected gametophytes
advantages of seeds
gymnosperms
angiosperms
monocots
eudicots
Lots of specialized terms are used to
describe the life cycle of see plants.
Here, we will use the fewest we can,
and simply drastically. Fig. 30.3.
This whole structure is a ovule (integument,
the cells of the megasporangium, and the
cells of the megaspore). The megaspore is
formed by meiosis, so is a haploid
gametophyte, the rest is diploid sporophyte.
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Seed plants (Ch.30)
protected gametophytes
advantages of seeds
gymnosperms
angiosperms
monocots
eudicots
Lots of specialized terms are used to
describe the life cycle of see plants.
Here, we will use the fewest we can,
and simply drastically. Fig. 30.3.
One of the female gametophyte cells becomes an egg
(n). The rest divide to produce the rest of the cells of the
female gametophyte. A male gametophyte (n), or pollen
grain, enters the ovule, and the nucleus of one of its cells
acts like a sperm, and fertilizes the egg (= zygote).
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Seed plants (Ch.30)
protected gametophytes
advantages of seeds
gymnosperms
angiosperms
monocots
eudicots
Lots of specialized terms are used to
describe the life cycle of see plants.
Here, we will use the fewest we can,
and simply drastically. Fig. 30.3.
The haploid female gametophyte (minus the cell that
became the egg) becomes a mass of tissue that will
provide a food supply for the new embryo developing from
the zygote. The integument becomes a hard seed coat.
Note that the embryo stops developing until it germinates
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thus the “baby plant” in a peanut!
Seed plants (Ch.30)
protected gametophytes
advantages of seeds
gymnosperms
angiosperms
monocots
eudicots
The advantages of seeds are pretty obvious - there is no
need for the gametophyte to live in a damp place so
sperm can swim to the egg - seed plants can, and do, live
everywhere.
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Seed plants (Ch.30)
protected gametophytes
advantages of seeds
gymnosperms
angiosperms
monocots
eudicots
Gymnosperms are seed plants that do not
have a fruit around the seed, and thus have
“naked seeds”. Most of us think of
gymnosperms as just “pines” (or conifers), but
there is quite a diversity. Ginkos live on
campus - have you seen one? The “fruit” is not
really a fruit, but part of the ovule..
pine
gingko
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Seed plants (Ch.30)
protected gametophytes
advantages of seeds
gymnosperms
angiosperms
monocots
eudicots
Angiosperms do not have naked seeds,
but seeds surrounded by a n extra layer
of tissue that forms a fruit (which may be
juicy or dry). Fig. 30.8, 30.9
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Seed plants (Ch.30)
protected gametophytes
advantages of seeds
gymnosperms
angiosperms
monocots
eudicots
But of course,
angiosperms also have
flowers! Fig. 30.7. You
do not have to memorize
all the parts, but know
that that most flowers
have both male, pollen
producing parts, and
female ovules.
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Seed plants (Ch.30)
protected gametophytes
advantages of seeds
gymnosperms
angiosperms
monocots
eudicots
Almost all angiosperms
fall naturally into two
groups, monocots (one
cotyledon, or seed leaf)
and dicots (two
cotyledons). A few
dicots don’t form a
clade, but the huge
majoroty that do are
called true dicots, or
eudicots. Fig. 30.12
(p. 603)
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Seed plants (Ch.30)
protected gametophytes
advantages of seeds
gymnosperms
angiosperms
monocots
eudicots
Fig. 30.13. Angiosperms and
animals have evolved very intricate
mutualistic interactions involving
pollination - interactions that
benefit both.
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Learning goals: Lecture 3, Biological Diversity
(Plants and Fungi)
Readings: Chapters 29, 30, and 31 (read all of these, but the
parts covered in lecture are most likely to be on a test ).
Land plants II - Seed plants (Ch.30)
Land Plants I- how land plants
colonized land (Ch. 29)
Tiny gametophytes protected in
ovules and pollen; advantages of
Land plants evolved from green
seeds; Gymnosperms have “naked
algae; terrestrial adaptations;
seeds”; Angiosperms have seeds in
alternation of generations;
fruits; Monocots, Eudicots
bryophytes dominated by
gametophyte generation; ferns Fungi (Ch. 31)
dominated by sporophyte
Characteristics; fungi reproduce by
spores; fungal origins and
relationships; importance
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Lecture 3 spe cific reading. The en tir e reading is Chap ters 29, 30, and 31
Fig. 28.3, p. 568 – read just figure legends – note that coml ex algae li ke Ulva seem ve ry
“plant-like”
Fig. 29.3. p. 574, Genetic Evidence
Fig. 29.5, p. 576, (top), p. 576, (als o p. 574, Adaptations enabling the move to la nd.
Fig. 29.5 (bottom) , p. 576, Alt ernation of gene rations
Fig. 29.8, p. 581, als o p. 580, Bryophy te gametophtes
Fig. 29.12, p. 585
Fig. 29.14, p. 587, take a look at the c lub moss and hor setail pho tos, simil ar to one shown
in lecture
Fig. 29.15, p. 588, read Sign ifi canc e of seedless vascu la r plants (even though not
discuss ed in lecture)
Fig. 30.2, p. 592
Fig. 30.3, p. 593, als o p. 592 Ovu les and Produc tion of Egg s, Poll en and Produc it on of
sperm, p. 593, the Evo lutiona ry advan tages of seeds
Fig. 30.7, p. 598, Flowers
Fig. 30.8, p. 598, p. 598-599, Fruits
Fig. 30.9, p. 599, more fruit s.
Fig. 30.12, left side, p. 603, focus on co tyledons and leaf venation, but read all cha rcters
that disti ngu ish monocots and dicots.
Fig. 30.13, p. 604
Fig. 31.2, p. 609
Fig. 31.6, p. 611
Fig. 31.7, p. 611
Fig. 31.5, p. 611. If you want to unde rstand about the he terokaryotic stage , you may
wan t to read p. 610-611, Sexua l r eprodu ction
Fig. 31.23, p. 621-622, Lichens
Fig. 31.25, p. 622-623, Pathogens
Fig. 31.26, p. 623, Practical Uses of Fung i
70
Pine Life-Cycle
71
pollen cone
male or
pollen
cone
Female or ovulate cone
ovulate cone
72
male cone
microsporophyll
microsporangium
73
female cone
ovule
.megasporangium
scale
“megasporophyll”
74
seeds
scale
75
Coniferophyta
Yew
Juniper
76
Coniferophyta
Bristlecone
Pine
77
Coniferophyta
Giant Redwood
or
Sequoia
78
Hemlock
Coniferophyta
Spruce
79
Coniferophyta
Bald Cypress
80
Douglas Fir
Coniferophyta
Fi
r
81
Cycadophyta
: cycads 82
Ginkgophyta:
Ginkgo biloba
83
Gnetophyta:
Ephedra
mormon tea
84
Gnetophyta:
Gnetum
85
Gnetophyta:
Welwitschia
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Leaves:
Many different sizes, shapes. (Pine
needles, cabbage, oak, etc.)
* Capture sun’s energy for photosynthesis
* Structure of a leaf:
- Upper surface cells
- Chloroplasts
- Veins with xylem and phloem
- Underside surface cells
- Stomata
(“stoma” in Greek means “mouth”, opening)
87
The
Structur
e of a
Leaf
88
Cuticle
Upper Epidermis
Palisade mesophyll
Vascular Bundle
Spongy mesophyll
Lower Epidermis
89
90
VENATION
91
Transpiration = process of evaporation from leaves.
* Too much evaporation and the plant shrivels and
dies
* Closing the stomata helps slow down transpiration.
92
Stems: support the plant and carry substances
between the roots and leaves.
* Some stems also store food (starches) like in
asparagus.
* They vary in size and shape:
- Boabab tree has a huge stems.
- Cabbage have short, hidden stems.
93
94
* Structure of stems:
- Herbaceous (soft) [dandelions,tomato plants]
- Woody (hard) like trees and rose bushes
- Both have xylem and phloem,
but woody stems have extra layers:
Outer Bark
Inner Bark (phloem)
Cambium (to produce new phloem and xylem)
Sapwood (active xylem - still transporting)
Heartwood (inactive xylem); just gives
strength
95
Pith (center storing food & water in young
Parts of a Woody Stem
96
Annual Rings = xylem rings
* Spring Xylem is wide & light brown (grows rapidly)
* Summer Xylem is thin & darker (grow slower)
* Each pair of light & dark rings = one year’s growth.
97
98
Roots:
(Anchors. Absorbs water & nutrients from soil)
* Two Types
1. Taproot = deep into soil
2. Fibrous Roots = several branching main
roots
* Root structure
- Root Cap the rounded tip containing dead
cells.
- Root hairs increase surface absorption area
- Cambium produces xylem and phloem tissues.
99
- Xylem transports substances up to the plant
Fibrous Roots
Tap Root
100
Root:
Internal
Structure
101
Roots do not absorb water and minerals through a
smooth Epidermis. Tiny, hairlike projections called
ROOT HAIRS on the epidermis absorb water and
dissolved minerals from the soil. Root Hairs also
INCREASE the Surface Area of the Plant Roots.
102
Epidermis
Cortex
Pith
Xylem
Phloem
Endodermis
Dicot Root
Monocot Root
103
Gymnosperms
Gymnosperm = seed plant that produces naked seeds.
* Many have needlelike or scalelike leaves and deep
root systems.
* Note the book says fossils indicate there were
many more gymnosperms in the past than today.
This is because the global flood 4,000 years ago
wiped out many plants.
(The dates given by many books of millions of years
are false guesses. See the booklet by Dr.
104
Humphreys.)
Types of Gymnosperms:
- Cycads (look like palm trees with large
cones)
- Ginkgo (only the Ginkgo biloba survives
today)
- Gnetophytes (found only in deserts
- Conifers (largest & most common, pines,
cedars, etc.)
[Conifers are evergreens: keep needles all year]
105
Oldest living organism – Bristlecone Pine
About 4,000 years old = just after Noah’s
Flood.
106
Reproduction of Gymnosperms:
* Cones – covered in scales, both male and female
cones are produced.
- Pollen is produced by male cones, and pollen are
tiny cells that later become sperm cells.
- Ovule is a structure containing an egg cell.
Pollination = transfer of pollen from male structure to
female part.
(Pollen falls from a male cone to a female cone and
fertilizes an ovule, which develops into a seed, with the
zygote as the embryo part of the seed. It can take two
years for seeds to mature, then the cones open & wind
107
carries the seeds off.)
The Life
Cycle
Of a
Gymnosperm
108
Angiosperms
Angiosperms – Two characteristics:
1. flowers
2. fruit
(To remember, think: “Angie” likes flowers, but “Gym” does
not.)
* They produce seeds inside a fruit.
* Flower = angiosperm reproductive structure
* Fruit starts as an Ovary =
where the seeds develop
109
Flower Structure:
Not all flowers have same
parts. Some have only male parts.
* Sepals = leaf-like structures covering a bud.
* Petals = colorful structures of an open flower.
* Stamens = male parts (stalks topped by knobs)
* Pistils = the female parts in the center of the
flower.
- Stigma = sticky tip of the pistil
- Style = tube connecting stigma to ovary.
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111
112
The Structure of a Flower
113
Flower Structure
Stigma
Filament
Style
Anther
Ovary
Receptacle
Petal
Sepal
Ovule
114
Life Cycle
Of an
Angiosperm
115
Reproduction of Angiosperms:
* Pollination = Pollen falls on a stigma when wind, bees, or
bats carry it. (Sugar-rich nectar in the flower attracts bees
or bats.)
* Fertilization = sperm & egg join together in the flower’s
ovule.
- The zygote develops into the embryo part of the
seed.
- The ovary around the seed develops into a fruit.
(Apples, cherries, tomatoes, squash, etc. are all fruit.)
* Dispersal – animals eat the fruit and the seeds come out
the other end.
116
Two types of Angiosperms:
1. Monocots – have only one seed leaf (cotyledon)
(grasses, corn, wheat, rice, lilies, tulips)
(flowers have either 3 petals or a multiple of 3 petals)
(long slender leaves with veins parallel like train rails)
(vascular tissue scattered randomly in the stem)
2. Dicots – have two cotyledons
(roses, violets, plus oak, maple, bean, and apple trees)
(flowers have 4 or 5 petals or multiples of these
numbers)
(leaves are wide, with veins branches off one another)
(vascular tissue bundles arranged in a circle)
Angiosperms are used for food, clothing (cotton),
Michael’s medicine (digoxin)
117
Seed Structure Examples:
118
Plant Responses and Growth
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Tropism = a plant’s growth response toward or
away from a stimulus.
* Positive tropism is when it grows toward a
stimulus.
* Negative is when it grows away from it.
* Stimuli can be light, touch, and even gravity.
- Touch (thigmotropism)
[vines coil around anything they touch.]
- Light (phototropism)
[leaves, stems, etc, grow toward light.]
- Gravity (gravitropism)
(Positive) roots grow toward gravity’s pull
(Negative) stems grow away from its pull
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Hormones = a chemical that affects how the plant
grows and develops, & make tropism possible.
* Hormones also control germination, formation of
flowers, stems, and the shedding of leaves and
ripening of fruit.
* Auxin is an important hormone that speeds up
plant cell growth rate.
- If light shines on one side of a stem, auxin
moves to the shaded side and causes that side
to grow faster so the stem bends toward the light
as it grows.
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Life Spans of Angiosperms:
* Annuals = complete a life cycle in one year.
(pansies, wheat, tomatoes, cucumbers, etc)
* Biennials = complete life cycle in two years.
(Second year they produce flowers and seeds.)
(Parsley, celery, etc)
* Perennials = live for more than two years
(Oak tree, honeysuckles, etc)
(Roots and stems survive the winter)
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