shs

What modern type of algae closely resembles the algal ancestor of plants

Charophyta

Land plants characteristic

Photosynthetic ( Photoautotrophs)

Cell walls made of cellulose

Alternation generations

Multicellular

Sessile

Benefits of terrestriality

More sunlight

More nutrients

More CO2

Less competition

Fewer predators

Fewer parasites / diseases

Challenges of terrestriality

Less water

Lack support

UV

Changing conditions

Reproduction

Gametophyte

Haploid phase of plant

Generates gametes by mitosis

Sporophyte

Diploid phase of a plant

Generates spores by meiosis

Gametophyte dominant

Ferns are dominant in gameotphyte, sporophyte stage is reduce and is dependent on the g stage is independent

Sporophyte

Angiosperms, sporophyte is dominant and independent stage, g stage is dependent on s for nutrients and protection

Homospory

1 sporangium , mostly 1 type of spore will develop into a bisexual gameotyphe

Heterospory

2 sporangia 2 types of spores male and female

Bryophytes NON VASCULAR

-no vascular tissue limits size

-tissues only few cells thick

Gametophyte dominant 1n

Must live in moist places

-mosses

Vascular plants

Complex multicellular roots and leaves

Absorb nutrients provide anchor, photosynthetic organs

Sporophylls - sporangia + sporopollenin walls = terrestrial adaptation

Sporophyte dominant life cycle

Pterophytes SEEDLESS VASCULAR PLANTS

ferns

sporophyte dominant

gametophyte independent smaller than sporophyte

Flagellated sperm must swim to reach egg

Need water to reproduce

Seed vascular plants

Angiosperms and gymnosperms

Seeds have protective and nutrients

Heterospory

Pollen grains - male

Sporophyte independent, gametophyte dependent

Gymnosperms

naked

Ovule seed develops on surface of sphorophylls

Cones

Angiosperms adaptations

Whole genome duplication even aka polyploidy

1 water conducting vessel

2 double fertilization

3 flowers

4 fruits

Double fertilization

Pollen tube discharges two sperms into one ovule of female gametophyte

One sperm fertilizes the egg the other develops food storing endosperm

Sporophylls

Leaves or leaf like structures

Sepals and petals non reproductive

Stamens anther and filament = sperm

Chapels stigma and style and overt = egg

Biotic dispersal

Dispersed by animals

Pollination

Gymnosperms rely on wind

Angiosperms rely on animals

Dispersal of gametes

Pollen transfered to the carpel

Abiotic dispersal

Wind water