Plants

What can plants do?

1. Food

2. Stabilize environment

3. Beauty

4. Medicine

5. Provides oxygen

Plant Cell Structure includes:

• Chloroplasts and all membrane bound organelles

Energy Pyramid

1. Carnivores: Lion

2. Omnivores: Humans

3. Herbivores: Cow

4. Produces: Plants

Things needed for plants’ survival

• Sun

• Water

• CO2

• N2

• Stoma

Photosynthesis

CO2+H20+Sunlight=O2+Glucose

Stoma

Small openings on plants to bring in CO2 and release O2

Xylem

• Moves water and minerals from roots to leaves

• Always up

Phloem

• Moves sugar from leaves to other parts of plants

• Up and down

Plant Transportation System

Xylem transports reactants for photosynthesis while Phloem transports products on photosynthesis

Main Types of Plants

• Vascular

• Non-Vascular

Vascular Plants

• Has transportation system

• larger and taller

• True roots, leaves, and stems

• eg. most plants

Nonvascular Plants

• No transportation

• Relies on osmosis

• Small and low

• Lives in moist environments

• eg. Mosses

Osmosis

Movement of water from a region of high water concentration to a region of low water concentration through a semi-permeable membrane

Plant requirements on land

• Roots

• CO2

• Ability to get sunlight

Phylum: Tracheophyta

• Vascular

• Include ferns, angiosperms, gymnosperms

Phylum: Bryophyta

• Nonvascular

• Includes mosses

Root System Function

• Anchor the plant

• Sometimes food storage (carrots, etc)

• Collect water and nutrients

Plant body includes:

Root system and Shoot system

Shoot System

• Stems: support the plant and transport water, minerals, and sugars between roots and leaves

• Flowers/Fruits: flowers handle reproduction; fruits protect and disperse seeds

• Leaves: main site of photosynthesis

Veins of Leaves

• Continuous with Phloem and Xylem

• Either dicots or monocots

• Vascular system

Dicots

Net-like veins that spreads out

Monocots

Parallel veins

Epidermis

• Found top and bottom of leaf

• Waxy cuticle covers leaf and prevents water loss and injury

Stomata

Plural of stoma

Stoma

• Usually on underside of leaf epidermis

• Tiny openings for gas exchange

• Open when hydrated → CO₂ in, O₂ out

• Close when dehydrated → reduce water loss

• Controlled by guard cells (respond to light)

Bundle Sheath Cells

Palisade Mesophyll

• Long and narrow cells

• Upper layer of leaf

• Responsible for light absorption

• Includes chlorophyll

Spongy Mesophyll

• Loosely packed cells with air spaces between

• Air spaces are connected to stomata and allows for efficient gas and water exchange

Brown Algae

• Kingdom: Protista

• Phylum: Phaeophyta

• Marine and temperate regions

• Eg. Kelp

Red Algae

• Kingdom: Protista

• Phylum: Rhodophyta

• Deeper marine region

• Eg. Porphyra

Green Algae

• Kingdom: Protista

• Phylum: Chlorophyta

• Unicellular, Colonial, or Multicellular

• Found in all environment

Unicellular Green Algae

• Common in fresh water as part of phytoplankton

• Unicellular photosynthetic organisms

Multicellular Green Algae

• Ancestor of land plants

• Eg. Sea Lettuce

Colonial Green Algae

• Lives in long filaments or as colonial spheres

• Eg. Volvox

Desiccating

Dying from moisture removal

Plant Adaptations on Land

• Seed as protection for embryo

• Stomata for gas exchange

• Xylem and phloem for water and nutrient transportation

• Waxy cuticle to prevent desiccation

Bryophytes

• Swimming Sperm

• Non-vascular

• No true roots

• Spores for reproduction

• Lifecycle dominated by haploid gametophyte stage

• Kingdom: Bryophyta

• Eg. Moss, Liverworts, Hornworts

Gametophyte

• Haploid (n) stage of a plant that produces gametes (sperm and eggs) by mitosis.

• Has archegonium and antheridium

Antheridium

• Male reproductive structure

• Produces flagellated sperm

• Haploid (n)

Archegonium

• Female reproductive structure

• Produces eggs

• Haploid (n)

Rhizoid

Anchor for gametophytes

Sporophyte

• Diploid (2n)

• Grows out of archegonium and forms spore capsule

• Contains vascular tissue in tracheophytes

• Produces haploid spores through meiosis

Spore Capsule

• Contains sporangium

• On and apart of sporophytes

Sporangium

• Contains no chlorophyll

• Relies on Gametophyte for nutrition

Protonema

Newly formed and unmatured plant

Plant Life Cycle

• Gametophyte Generation

• Sporophyte Generation

Alternation of Generations

Plant life cycle in which organisms switch between a haploid gametophyte stage and a diploid sporophyte stage.

Pteridophytes

• Sporophyte dominant

• Vascular

• Flagellated sperm

• Spores for reproduction

• No seeds, so called “Seedless Vascular Plants”

• Alternation of Generation

Prothallus (Prothallium)

• Heart-shaped haploid gametophyte of ferns

• photosynthetic

• Grows rhizoids

Sori

A cluster of Sporangia and found on underside of fern sporophyte

Sporangia

A structure that produces and holds Spores

Bryophytes’ Life Cycle

• Gametophyte produces gametes (n)

• Sperm swims to egg

• Fertilization occurs (2n)

• Zygote develops into sporophyte (2n) attached to gametophyte

• Sporophyte produces a sporangia

• Meiosis produces spores

• Spores disperse and germinate into protonema (n)

Pteridophytes’ Life Cycle

• On fronds, sori are formed from sporangia

• Sporangia undergo meiosis to spores (n)

• Spores grow into prothallus (n)

• Gametophyte produces gametes

• Sperm swims to egg

• Zygote is formed (2n) and develops to sporophyte (2n)

Examples of Pteridophytes

• Ferns

• Horsetail

• Psilotum

Ferns benefits

• Fed dinosaurs

• Decayed into deposits of coal and oil