Lecture 01 PLANTS PART I Study Guide

8/8/2019 Lecture 01 PLANTS PART I Study Guide

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PLANTS


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________________________

________________________

________________________ ________________________

General Characteristics


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Mineral absorption

Require large amounts of inorganic minerals

Ex ____________________________

Absorb these materials along with water

through roots from the soil


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Water Conservation

Cuticle ________________________ Stomata _______________________

Guard cells _____________________

In most plants water enters through roots as

liquids and exits through underside of leaves

as water vapor


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Reproduction

Alternation of generations

A diploid generation alternates with a haploid

generation

Diploid generation _____________________

Haploid generation ____________________


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Multicellular terrestrial photosynthesizers

Evolved from green algae

Adapted to life on land by

__________________________________

__________________________________

__________________________________


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Evolution of Plants

Once established on land, developed otherfeatures that aided their evolutionary success in

the new habitat

Early plants exhibited no difference between

their above ground and below ground parts

Roots and shoots with specialized structures

evolved suited to its particular environment

The evolution of vascular tissue allowedplants to grow larger


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Key evolutionary innovations

____________________________________________

______________________

______________________


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Non-vascular plants

Lack a transport mechanism for water andnutrients

Restriction on size

Osmosis and diffusion only transport ofmaterials

Include

__________ (6,000 species; Hepaticophyta)__________ (100 species; Anthocerophyta)

__________ (9,500 species, Bryophyta)


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Diversity of Non-

vascular plants


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LIVERWORTS (PHYLUM HEPATOPHYTA)

HORNWORTS (PHYLUM ANTHOCEROPHYTA) MOSSES (PHYLUM BRYOPHYTA)

Gametophore of

female gametophyte

Marchantia polymorpha,

a thalloid liverwort

Foot

Sporangium

Seta

500m

Marchantia sporophyte (LM)

Plagiochila

deltoidea,

a leafy

liverwort

AnAnthoceros

hornwort species

Sporophyte

Gametophyte

Polytrichum commune,

hairy-cap moss

Sporophyte

Gametophyte

Figure 29.9


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Bryophyta Moss

Alternation of generations

Gametophyte larger and longer living thansporophyte

Exhibit strands of conducting cells

Very primitive vascular system


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Moss life cycle

Mature

sporophytes

Young

sporophyte

Malegametophyte

Raindrop

Sperm

Key

Haploid (n)

Diploid (2n)

Antheridia

Female

gametophyte

Egg

Archegonia

FERTILIZATION

(within archegonium)

Zygote

Archegonium

Embryo

Femalegametophytes

Gametophore

Foot

Capsule

(sporangium)

Seta

Peristome

Spores

Protonemata

Bud

Bud

MEIOSIS

Sporangium

Calyptra

Capsule with

peristome (LM)

Rhizoid

Mature

sporophytes

Spores develop into

threadlike protonemata.1

The haploid

protonemata

produce budsthat grow into

gametophytes.

2Most mosses have separate

male and female gametophytes,

with antheridia and archegonia,

respectively.

3

A sperm swims

through a film of

moisture to an

archegonium and

fertilizes the egg.

4

Meiosis occurs and haploid

spores develop in the sporangium

of the sporophyte. When thesporangium lid pops off, the

peristome teeth regulate

gradual release of the spores.

8

The sporophyte grows a

long stalk, or seta, that emerges

from the archegonium.

6

The diploid zygote

develops into asporophyte embryo within

the archegonium.

5

Attached by its foot, the

sporophyte remains nutritionally

dependent on the gametophyte.

7

Figure 29.8


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Vascular Plants

__________ phyla

Exhibit highly specialized cells

__________________________________________________________________

_________________________________

Seedless

Seeded


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Primary growth

Increase in length Secondary growth

Increase in diameter

Vascular plants have specialized vasculartissue made of tubes that conduct water to

the leaves. Also have cells that from

cylinders to conduct food from leaves.


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Seedless

Club mosses (Lycophyta)

Ferns (Pterophyta; includes horsetails & whisk

ferns)

Most abundant seedless vascular plants

11,000 species Found throughout the world

More abundant in the tropics

Free-swimming sperms that require free water

for fertilization


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Seedless

vascularplant

diversity


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Ferns their life cycle

Lack seeds

Reproduce with spores In reproduction exhibit gametophyte (haploid)

and sporophyte (diploid) individuals, each

independent and self-sufficient

Gametophyte ______________________

Sperms swims fertilizes the egg

sporophyte

Sporophyte _______________________ These germinate and grow into gametophyte


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Fern sperm use flagella

to swim from the antheridia

to eggs in the archegonia.

Sporangia release spores.

Most fern species produce a single

type of spore that gives rise to a

bisexual gametophyte.

The fern spore

develops into a small,

photosynthetic gametophyte.

Although this illustration

shows an egg and sperm

from the same gametophyte,

a variety of mechanisms

promote cross-fertilizationbetween gametophytes.

On the underside

of the sporophytes

reproductive leaves

are spots called sori.

Each sorus is a

cluster of sporangia.

A zygote develops into a new

sporophyte, and the young plant

grows out from an archegonium

of its parent, the gametophyte.

Sporangium

Mature

sporophyteNew

sporophyteZygote

Archegonium

Egg

Haploid (n)

Spore Young

gametophyte

Fiddlehead

Gametophyte

Key

Sorus

Fern life cycle

MEIOSIS

FERTILIZATION

4

1 2 3

6

5


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Seed plants

Seeds protective cover for the embryo

Produce two kinds of gametophytes

Male and female

Both develop separately within the sporophyte

Male gametophyte pollen grains arise frommicrospores

Female gametophyte contains the egg and

develops from a megaspore produced within an

ovule Pollination _________________________________


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a seed is a dormant diploid embryo

encased in a protective coat with food

reserves. They play a critical role in

improving the chances of a plant tosuccessfully reproduce in a varied

environment


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Structure of a Seed

____________________________

____________________________

____________________________

In some seeds

Endosperm is used up during development of

embryo

Food is stored in structures called cotyledons


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Seeds provide the means for dispersion of

plants to new locations

Ex _____________________________

Once a seed falls to the ground it may liethere until conditions in the environment are

favorable germination occurs

Ex _____________________________


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Seeds have improved the adaptations of

plants to living on land

Dispersal __________________________ Dormancy __________________________

Germination ________________________

Nourishment ________________________


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Gymnosperms

Include 4 phyla Cycads (cycadophyta)

Gnetophytes (Gnetophyta)

Ginkgo (Ginkgophyta) Conifers (coniferophyta)

_________________

_________________

_________________

_________________


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Ginkgo


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GymnospermsDiversity

About 550 living

species

The tallest found incoastal California

and Oregon

Sequoia, reaches

over 100 meters


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Cycads

Mainly spread throughout the tropics

Only living species of ginkgo Resistant to air pollution, often planted along

city streets

Gnetophytes Only 3 kinds of plants

One of them grows on the sand of the desert

of Namibia (Southwest Africa)


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Gymnosperms: Their life cycle

Conifers from 2 kinds of cones Seed cones female gametophyte with egg cells

Pollen cones pollen grains (carried by the wind)

Many pollen grains are needed to ensuresuccessful pollination of a seed cone

When a pollen grain settles on a female conea pollen tube grows to deliver the male gameteto the female gametophyte containing the egg

Fertilization _ fusion of sperm and egg

zygote(beginning of the sporophyte generation)

Fertilized ovule forms a seed which can bedispersed into a new habitat


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Life cycle of a conifer


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Gymnosperms

are_______________________________

_________________________________

Angiosperms

are_______________________________

_________________________________

_


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Angiosperms

90% of all living plants

Over 235,000 species (trees, shrubs, herbs,

grasses, vegetables, grains)

Ex ________________________________

Plants in which the ovule is completely enclosed

by sporophyte tissue at fertilization

Have flowers (animal-dictated pollination, induceinsects and other animals to carry pollen)


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Angiosperm

diversity


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The flower

Reproductive organ of angiosperm plants

Color and nectar attract insects whichtransport pollen to another flower

Basic structure

Receptacle __________________________

Whorls ______________________________

Sepals (outer most whorl)

______________________________________

Petals _______________________________

Stamen ______________________________

Carpel _______________________________


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The lower portion of the carpel contains the ovary

The style rises from the ovary and contains the sticky

stigma which is the pollen receptor


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Flowers can be viewed as pollinator-

attracting devices, with different kinds of

pollinators attracted to different kinds of

flowers.


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Pollinators carry pollen from one individual

flower to another of the same species.

Bees___________________________________

___________________________________

___________________________________

Butterflies

Moths

__________________________________

__________________________________


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Flies__________________________________

Hummingbirds and sunbirds pollinate redflowers___________________________________

___________________________________

Some angiosperms rely on windpollination Ex _____________________________

Some aquatic species watertransportation


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The life Cycle of angiosperms

Produce endosperm a nutritious tissue withtheir seeds

Double fertilization Male gametophyte produces 2 sperms

Adhesion of pollen to stigma pollen tube growsuntil it reaches ovule in ovary

One sperm fuses with the egg

The other sperm fuses with polar nuclei (other productof meiosis) to form a triploid endosperm cell

This divides rapidly to become the nutritiveendosperm in the seed


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In some angiosperms (beans and peas)

The endosperm is fully used up by the time

the seed is mature Food reserves store in swollen, fleshy leaves

cotyledons

Others (corn) Mature seed contains lots of endosperm,

which is used after germination


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Classification of angiosperms embryos

Dicots

_______________________________________

_______________________________________

_______________________________________

Ex _____________________________________


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Monocots

_____________________________________

_____________________________________

_____________________________________ Ex __________________________________

Also differences in the organization of

vascular tissue between these 2 groups


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Fruits

Mature ripened ovary containing fertilized seeds

Provide angiosperms with an efficient way to disperseprogeny using animals

Fleshy and tasty fruit

Seeds within fruits are resistant to digestion and chewing

Transported within the animal and released through the

feces away from the parent, undamaged and ready togerminate

Some are dispersed by water

Many specialized for wind dispersal

Small particles Structures that allowed them to be carried with wind currents


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Lecture 01 PLANTS PART I Study Guide