chapter 29 plant diversity: how plants colonized land

Chapter 29

Plant Diversity:How plants colonized land

Plant Origins

Ch

loro

ph

yta

Pla

nta

e

Ancestral eukaryote

Rh

od

op

hyt

a

Fu

ng

i

Dip

lom

on

ad

ida

Par

aba

sal

a

Eu

gle

no

zoa

Alveolata Stramenopila Ce

rco

zoa

Ra

dio

lari

a

Amoebozoa An

ima

lia

Ch

oan

ofl

ag

ella

tes

Figure 28.4

See Fig. 29.7

Land plants evolved from

Charophyceans (multicellular,

eukaryotic, green-algae protists)

Land plants

Origin of land plants(about 475 mya)

Ancestralgreen alga

Ch

aro

ph

ycea

ns

Liv

erw

ort

s

Ho

rnw

ort

s

Mo

sses

Lyc

op

hyt

es(c

lub

mo

sses

etc

.)

Pte

rop

hyt

e (f

ern

s, h

ors

etai

ls,

wh

isk

fern

)

Gym

no

sper

ms

An

gio

sper

ms

Hashed lines indicate uncertainties

See Fig. 29.7

Land plants evolved from

Charophyceans (multicellular,

eukaryotic, green-algae protists)

Chara (a Charophycean

pond alga)

Land plants


Ancestralgreen alga

Ch

aro

ph

ycea

ns

Liv

erw

ort

s

Ho

rnw

ort

s

Mo

sses

Lyc

op

hyt

es(c

lub

mo

sses

etc

.)

Pte

rop

hyt

e (f

ern

s, h

ors

etai

ls,

wh

isk

fern

)

Gym

no

sper

ms

An

gio

sper

ms


See Fig. 29.7

Land plants


Ancestralgreen alga

Ch

aro

ph

ycea

ns

Liv

erw

ort

s

Ho

rnw

ort

s

Mo

sses

Lyc

op

hyt

es(c

lub

mo

sses

etc

.)

Pte

rop

hyt

e (f

ern

s, h

ors

etai

ls,

wh

isk

fern

)

Gym

no

sper

ms

An

gio

sper

ms


The evidence consists of many

derived homologies of cellular micro-

structure and biochemistry (DNA,

chlorophyll, etc.)

Evolutionary innovations:

Colonization of land by the first bryophytes

See Fig. 29.7

Bryophytes(nonvascular plants)

Land plants


Ancestralgreen alga

Ch

aro

ph

ycea

ns

Liv

erw

ort

s

Ho

rnw

ort

s

Mo

sses

Lyc

op

hyt

es(c

lub

mo

sses

etc

.)

Pte

rop

hyt

e (f

ern

s, h

ors

etai

ls,

wh

isk

fern

)

Gym

no

sper

ms

An

gio

sper

ms



Advent of a vascular system with the origin of vascular plants

See Fig. 29.7


Vascular plants

Land plants

Origin of vascular plants (about 420 mya)


Ancestralgreen alga

Ch

aro

ph

ycea

ns

Liv

erw

ort

s

Ho

rnw

ort

s

Mo

sses

Lyc

op

hyt

es(c

lub

mo

sses

etc

.)

Pte

rop

hyt

e (f

ern

s, h

ors

etai

ls,

wh

isk

fern

)

Gym

no

sper

ms

An

gio

sper

ms


Seedless vascular plants


Origin of seeds (embryo packaged with a supply of nutrients inside a protective coat)

See Fig. 29.7

Bryophytes(nonvascular plants) Seedless vascular plants Seed plants

Vascular plants

Land plants

Origin of seed plants(about 360 mya)



Ancestralgreen alga

Ch

aro

ph

ycea

ns

Liv

erw

ort

s

Ho

rnw

ort

s

Mo

sses

Lyc

op

hyt

es(c

lub

mo

sses

etc

.)

Pte

rop

hyt

e (f

ern

s, h

ors

etai

ls,

wh

isk

fern

)

Gym

no

sper

ms

An

gio

sper

ms



Evolution of flowers (seeds develop inside chambers called ovaries, which originate in flowers that mature into fruits)

See Fig. 29.7


Vascular plants

Land plants




Ancestralgreen alga

Ch

aro

ph

ycea

ns

Liv

erw

ort

s

Ho

rnw

ort

s

Mo

sses

Lyc

op

hyt

es(c

lub

mo

sses

etc

.)

Pte

rop

hyt

e (f

ern

s, h

ors

etai

ls,

wh

isk

fern

)

Gym

no

sper

ms

An

gio

sper

ms



Alternation of generations

See Fig. 29.7


Vascular plants

Land plants




Ancestralgreen alga

Ch

aro

ph

ycea

ns

Liv

erw

ort

s

Ho

rnw

ort

s

Mo

sses

Lyc

op

hyt

es(c

lub

mo

sses

etc

.)

Pte

rop

hyt

e (f

ern

s, h

ors

etai

ls,

wh

isk

fern

)

Gym

no

sper

ms

An

gio

sper

ms


Review of chromosome number

• A diploid nucleus (2n) has two of each kind of chromosome

• A haploid nucleus (n) has only one of each kind of chromosome

Human chromosomes from a diploid cell

No alternation of generations

Animal Life Cycle:

Diploid phase is dominant

See Fig. 13.5


Animal Life Cycle:

Diploid phase is dominant

See Fig. 13.6

Key

Meiosis Fertilization

Haploid

Diploid

n

n

n

2n 2n

Mitosis

ZygoteDiploid multicellular

organism

Gametes

Haploid


Fungal Life Cycle (shared by some protists):

Haploid phase is dominant

See Fig. 13.6

Meiosis Plasmogamy & Karyogamy

n

2n

Gametesor

hyphae

Key

Diploid

MitosisMitosisn

nn

n

Zygote-like cell

Haploid multicellular organism

Spores

Haploid

See Fig. 13.6


n

2n

Zygote

Diploid multicellular

organism (sporophyte)

Gametes

Key

Diploid

Mitosis


Plant Life Cycle (shared by some algae):

2n

nn

n

n

Haploid multicellular organism (gametophyte)

MitosisMitosis

Spores

Haploid or diploid phase is dominant, depending on the lineage

Haploid

See Fig. 13.6


n

2n

Zygote



Gametes

Key

Diploid

Mitosis


2n

nn

n

n


MitosisMitosis

Spores

Spore = reproductive cell that can develop into a new organism

Haploid

See Fig. 13.6


n

2n

Zygote



Gametes

Key

Diploid

Mitosis


2n

nn

n

n


MitosisMitosis

Spores

Gamete = reproductive cell that must fuse with another gamete

Fertili-zation

Meiosis occurs in specialized

cells to produce spores

Mitosis results in gametophyte

growth

Mitosis occurs in specialized

cells to produce gametes

Mitosis results in sporophyte growth


If humans had alternation of generations

Further Adaptations of Land Plants

Apical meristems

Shoot Root

See Fig. 29.5


Multicellular, dependent embryos with placental transfer cells

Embryo

Maternal tissue

See Fig. 29.5


The spore mother cells of diploid sporangia produce protected (walled) haploid spores

SporeSporangium

See Fig. 29.5


Multicelluar, haploid gametangia produce gametes (in all but angiosperms)

Archegonium: female gametangium

Egg

Archegonium

See Fig. 29.5


Multicelluar, haploid gametangia produce gametes (in all but angiosperms)

Antheridium: male gametangium

Sperm

Antheridium

See Fig. 29.5


Characters for conserving water

Waxy cuticle coating the epidermis


Characters for moving water

Lignified vascular tissues (found in all but bryophytes)

Lignin


Characters for moving water

Phloem and xylem

I. Non-vascular

Plants

(Bryophytes)

See Fig. 29.7

Dominant plants on Earth through the first 100 million years of land plants’ existence


Land plants




Ancestralgreen alga

Ch

aro

ph

ycea

ns

Liv

erw

ort

s

Ho

rnw

ort

s

Mo

sses

Lyc

op

hyt

es(c

lub

mo

sses

etc

.)

Pte

rop

hyt

e (f

ern

s, h

ors

etai

ls,

wh

isk

fern

)

Gym

no

sper

ms

An

gio

sper

ms


I. Non-vascular

Plants

(Bryophytes)

II. Vascular Plants

A. Seedless

See Fig. 29.7

Dominant plants in Carboni-ferous, i.e., today’s fossil fuels

Bryophytes(nonvascular plants) Seedless vascular plants

Vascular plants

Land plants




Ancestralgreen alga

Ch

aro

ph

ycea

ns

Liv

erw

ort

s

Ho

rnw

ort

s

Mo

sses

Lyc

op

hyt

es(c

lub

mo

sses

etc

.)

Pte

rop

hyt

e (f

ern

s, h

ors

etai

ls,

wh

isk

fern

)

Gym

no

sper

ms

An

gio

sper

ms


I. Non-vascular

Plants

(Bryophytes)

II. Vascular Plants

A. Seedless

B. Seed Plants

See Fig. 29.7

Dominant plants on Earth today


Vascular plants

Land plants




Ancestralgreen alga

Ch

aro

ph

ycea

ns

Liv

erw

ort

s

Ho

rnw

ort

s

Mo

sses

Lyc

op

hyt

es(c

lub

mo

sses

etc

.)

Pte

rop

hyt

e (f

ern

s, h

ors

etai

ls,

wh

isk

fern

)

Gym

no

sper

ms

An

gio

sper

ms


I. Non-vascular

Plants

(Bryophytes)

II. Vascular Plants

A. Seedless

B. Seed Plants

i. Gymno-

sperms

ii. Angio-

spermsSee Fig. 29.7


Vascular plants

Land plants




Ancestralgreen alga

Ch

aro

ph

ycea

ns

Liv

erw

ort

s

Ho

rnw

ort

s

Mo

sses

Lyc

op

hyt

es(c

lub

mo

sses

etc

.)

Pte

rop

hyt

e (f

ern

s, h

ors

etai

ls,

wh

isk

fern

)

Gym

no

sper

ms

An

gio

sper

ms


Bryophytes

Gametophyte dominant;

sporophyte dependent;

gametophyte independent

See Fig. 29.8

Bryophytes

MeiosisFertilization

KeyHaploidDiploid

Male gametophyte

Female gametophyte

Gameto-phytes produce gametes by mitosis

Antheridia

Archegonia

Sperm (flagellated)

Egg

See Fig. 29.8

Bryophytes

MeiosisFertilization

KeyHaploidDiploid

Male gametophyte

Female gametophyte

Antheridia

Archegonia

Egg

Zygote

A zygote begins the sporo-phyte generation

Mature sporo-phytes produce spores by meiosis See Fig. 29.8

Sporophytes

Spores

Sperm (flagellated)

Sporangium

Bryophytes

Moss gametophytes and sporophytes

Bryophytes

Thin structure allows distribution of materials without vascular system

Rhizoids anchor, but do not play a primary role in water and nutrient uptake

Phylum Hepatophyta - liverworts

P. Anthocerophyta hornworts

P. Bryophyta mosses

Bryophytes

Ball or Spanish “moss” – an Angiosperm

Bryophytes


Sporophyte dominant; sporophyte initially

dependent; gametophyte independent

See Fig. 29.12


Meiosis

Fertilization

Key

Haploid

Diploid

Gametophyte

Antheridium

Egg

Sperm (flagellated)

See Fig. 29.12

Archegonium

Gametophytes produce gametes by mitosis

Fern prothallus = gametophyte




Meiosis

Fertilization

Key

Haploid

Diploid

Gametophyte

Antheridium

Egg

Sperm (flagellated)

See Fig. 29.12

Archegonium



Meiosis

Fertilization

Key

Haploid

Diploid

Gametophyte

Antheridium

Egg

Zygote

Mature sporophytes

Sperm (flagellated)

See Fig. 29.12

Archegonium

Youngsporophyte

Gametophyte

A zygote begins the sporophyte generation


Meiosis

Fertilization

Key

Haploid

Diploid

Gametophyte

Antheridium

Egg

Zygote

Mature sporophytes

Spores

Sperm (flagellated)

See Fig. 29.12

Archegonium

Youngsporophyte

Gametophyte

Sporangium

Sorus

Sporophyll

Mature sporophytes produce spores by meiosis

Sori = clusters of sporangia



See diagram on pg. 586

Homosporous spore production (most seedless vascular plants)

Heterosporous spore production (some seedless vascular plants; all seed plants)

Sporangium insporophyll

(2n)

Single type of spore

(n)

Bisexual gametophyte

Eggs

Sperm


Meiosis

Fertilization

Key

Haploid

Diploid

Gametophyte

Antheridium

Egg

Zygote

Mature sporophytes

Spores

Sperm (flagellated)

See Fig. 29.12

Archegonium

Youngsporophyte

Gametophyte

Sporangium

Sorus

Sporophyll


See diagram on pg. 586

Homosporous spore production (most seedless vascular plants)

Heterosporous spore production (some seedless vascular plants; all seed plants)

Sporangium insporophyll

(2n)

Single type of spore

(n)

Bisexual gametophyte

Eggs

Sperm

Megasporangiumin megasporophyll

(2n)

Megaspore(n)

Female Gametophyte

(n)

Microsporangium in microsporophyll

(2n)

Microspore(n)

Male Gametophyte

(n)

Eggs(n)

Sperm(n)

Evolution of:

Leaves

(principal photosynthetic organs of vascular plants)


Evolution of:

Roots

(principal organs that anchor vascular plants and absorb water & nutrients)


Evolution of:

Vascular tissues

(conduits that distribute water & nutrients within vascular plants)


Phylum Lycophyta

“Club mosses”


Phylum Pterophyta

Horsetails

E.g., Equisetum


Strobilus – a group of sporophylls forming a cone

Phylum Pterophyta

Horsetails


Phylum Pterophyta

Whisk ferns


Phylum Pterophyta

Ferns

Terrestrial species are found on the ground


Phylum Pterophyta

Ferns

Resurrection fern is an epiphytic species, i.e., it grows

on other plants



A modern community


A diorama of an ancient community


A fossil stump of a seedless vascular plant

I. Non-vascular

Plants

(Bryophytes)

II. Vascular Plants

A. Seedless

B. Seed Plants

i. Gymno-

sperms

ii. Angio-

spermsSee Fig. 29.7


Vascular plants

Land plants




Ancestralgreen alga

Ch

aro

ph

ycea

ns

Liv

erw

ort

s

Ho

rnw

ort

s

Mo

sses

Lyc

op

hyt

es(c

lub

mo

sses

etc

.)

Pte

rop

hyt

e (f

ern

s, h

ors

etai

ls,

wh

isk

fern

)

Gym

no

sper

ms

An

gio

sper

ms


The Life Cycle of Animals – Illustrated for Humans

Generation 1

Multicellular individuals;Diploid (2n) cells

Unicellular gametes;

Haploid (1n) cells

Generation 2

Specialized cells undergo meiosis

to produce gametes

Gametes fuse during fertilization

to become a zygote

AY

aX

AaXY

From the single-celled zygote stage onward, cells undergo mitosis to increase

the number of cells in the maturing individual.

Unicellularzygote;

Diploid (2n)cell

Muticellular individuals;Diploid (2n) cells

AX

aX

AAXY

AaXX

AAXX

AaXY

Gen. 3

AaXX

The Life Cycle of Fungi – Illustrated for Bread Mold

Several generations

Diploid (2n) zygote

Several generations

Haploid (1n) cells of hyphae

Multiple rounds of asexual reproduction

possible; all cell divisions occur by

mitosis.

Brief inter-generationalzygote stage

Haploid (1n) cells of hyphae

Zygotic meiosis



mitosis.



mitosis.



mitosis.

Fusion of compatible hyphae to form a zygote

Aa

+-a

-

Haploid (1n) spore

A+

a-

a-

a+

The Life Cycle of Plants (Alternation of Generations) – Illustrated for a Dioecious Flower

Generation 1

Multicellular sporophyte

Unicellular spores

Generation 2

Specialized cells undergo meiosis to produce spores

Gametes fuse during fertilization

to become a zygote

aB

AaBb

Single-celled spores undergo mitosis to increase the number of cells in the

maturing gametophyte. Mature gametophyte produces gametes

by mitosis

Multicellular gametophyte

Ab

Haploid (1n) cells

Ab

aB

Unicellulargametes

Generation 3

Diploid (2n) cells

Multicellular sporophyte

Diploid (2n) cells

Unicellular spores of

gametophyte

Haploid (1n) cells

Pollengrain

Embryo sac

Gen. 4

AAbb

AaBb

AaBb

Unicellularzygote

aaBB

Specialized cells undergo meiosis to produce spores

Ab

aB

chapter 29 plant diversity: how plants colonized land

Documents

mya origin of land plants

mya origin of vascular

land slide

colonization of land

pterophyte ferns

vascular system

origin of seeds embryo

charophyceans multicellular