Plant basics

sporophyte

2n

gametophyte

n

sporangium

structure that produces spores through meiosis

gametangia

structure that makes gametes through mitosis (2 types)

Archegonia

Female gametangia

Antheridiais

Male gametangia (sperm)

Sporophyte to gametophyte

Meiosis

Gametophyte to sporophyte

Fertilization

Synapomorphy of land plants

A protected embryo by tissues of parent plant 

Land plants can also be called

Embryophytes

Vascular plants

Has tracheophytes

tracheophytes

Fluids conducting cells called traceids

Fusion of gametes results in

diploid zygote

Zygote (for plants) develops into:

Multicellular sporophyte

Non-vascular plants

Plants that don’t have tracheids

What do plants need on land?

- water transport mechanisms

- physical support

- mechanisms to distribute gametes and progeny

- avoid desiccation (drying out)

Adaptations of plants

- cuticle

- stomata

- gametangia

- embryos in a protective structure

- thick spore walls that prevent desiccation and decay

- pigments that protect against UV radiation

- mutually beneficial associations with fungi (mycorrhizae) that provide nutrient uptake from the soil

Cuticle

Waxy coating that retards water loss

Stomata

Openings in stems and leaves regulate gas exchange and water loss

Basic plant life cycle

:)

Sharded derived trait of plantae

Primary endosymbiosis

2 types of land plants

Vascular and nonvascular

Key synapomorphy of vascular plants

Tracheid and Branching independent sporophytes

Vascular system parts

Xylem and Phloem

Xylem

Conducts water and minerals from soil up to the rest of the plant

What provides support in Xylem

Lignin

Phloem

Conducts products of photosynthesis through the plant

Transport of water and minerals and rigid structural support allows plants to ________

Grow tall to compete for light and aids in spore dispersal

Branching independent sporophytes (in vascular plants)

- produce more spores

- develop in complex ways

The most ancient vascular plants were

homosporous

homosporous

one type of spore

heterosporous

multiple types of spores

megaspore

develop into female gametophyte - megagametophytes (eggs only)

Ovule

Megasporangium and the integument

microspore

divide mitotically to form male gamerophytes (pollen grain)- microgametophytes (sperm only)

Pollen grain

male gamerophytes

Seeded plants (vascular)

Gymnosporms and Angiosperms

3 new features in seeded plants

woody stem - pollen - seeds

Woody stem

Secondary growth that gives support and allows plants to grow above their competitors - many plants have lost this

Pollen

Sperm transfer that doesn’t require water

sporopollenin

in pollen grain walls - most resistant biological compound - prevents dehydration and chemical change

Seeds

embryo is protected until ready to germinate - has tissue from 3 generations

tissue in seeds

Seed coat that develops from integument (from the sporophyte parent) - Haploid female gametophyte tissue supplies nutrients for developing embryo - Embryo is the new diploid sporophyte generation

What is the evolutionary trend about the size of the sporophyte and the gametophyte?

Trend towards reduction of gametophyte generation in plant evolution

Pollination

When a pollen grain lands near a female gametophyte

Pollen tube

tube from the pollen grain that elongates and digests its way through the sporophyte tissue to the megagametophyte

Angiosperms

Protected/enclosed seeds

Gymnosperms

naked/unprotected seeds (no flowers or fruits)

Megastrobilus

Female cone - houses megasporangium

Microstrobulis

Male cone - houses microsporangium

Synapomorphies of angiosperms

- germination of pollen on stigma

- double fertilization

- endosperm (nutritive tissue for embryo

- phloem with companion cells

Corolla

Petals plural

Calyx

Sepals plural

Tepals

undifferentiated flowers (petals and sepals)

Perfect flowers

Both mega and microsporangia - can self pollinate

Imperfect flowers

Either mega or microsporangia - monoecious and dioecious

Red and odorless flowers are mostly pollinated by ____

Birds

Flowers that smell are often pollinated by ____

Insects

Flowers with conspicuous markings, or nectar guides are often pollinated by ___

Bees

Simple fruits

Develop from one carpel (plum or cherries)

Aggregate fruits

Develop from several carpels of a single flower (raspberry)

Multiple fruits

Develop from a cluster of flowers (pineapple or figs)

Accessory fruits

Develop from parts in additon to carpels and seeds (apple, pears, or strawberry)

Monocots

One cotyledon - vascular bundles arranged in scattered/no arrangement

Dicots/eudicots

two cotyledons - vascular bundles arranged in a circular bundle

Monoecious

Male and female flowers occur on the same plant

Dioecious

Male and female flowers are on different plants

genetic self-incompatibility

reject pollen from their own flowers - S locus genes encodes proteins in the pollen and style that interact during the recognition process

Nonvascular plant traits:

• no vascular transport system - plants are short

• water transport is via diffusion

• thin cuticle or no cuticle; most live in moist habitats

• lack true leaves, stems, and roots

• Sporophyte is nutritionally dependent on gametophyte

• water needed for reproduction

Multicellular diploid plant generation

Sporophyte

Multicellular haploid plant generation

Gametophyte