· Multicellular
· Photosynthesis
o Chloroplast with chlorophyll
· Most are terrestrial
· Cellulose in cell walls
· Store food as starch
· Lack mobility
1. Single celled algae è Aquatic plants
2. Aquatic plants èTerrestrial plants
1. Many problems with living on land
a. Support
b. Access to water and nutrients
i.Require system
ii. Root system
iii. Travel to all parts of the plant
c. Drying out
i.Waterproof layer called the cuticle
ii. Stomata allow passages for photosynthesis (closed when too warm)
iii. Gymnosperms have narrow leaves (minimize water loss)
d. Spreading gametes
i.Spores
ii. Seeds
1. Embryo inside surrounded by protective seed coat
2. Some seeds carried by wind, stick to fur, eaten
1. Non vascular plants (eg. Mosses)
a. Sexual and asexual reproduction
2. Vascular Plants (transport system)
a. 2 groups è seedless and seeds
1. Seedless Plants è ferns, horsetails
a. Produce spores in sori (sporangia on the back of the leaf)
2. Seed Plants
a. Gymnosperms è pine, spruce, Conifers
1. Seeds that are not enclosed
2. Reproduction
b. Angiosperms è flowering plants
1. Seeds that are enclosed (fruit)
2. Many different habitats
1. Monocots è grass, tulips, daffodils, palm trees
a. Parallel veins
b. One cotyledon (first leaf out of seed)
c. Flower part in multiples of 3
d. Root system fibrous
e. Vascular tissue scattered
2. Dicots è trees, common plants, maple trees, dandelions
a. Netlike veins
b. Two cotyledons (first leaf out of seed)
c. Flower part in multiples of 4/5
d. Vascular tissue in stems is arranged in a ring
3. Flowers
a. Most are perfect
b. Some imperfect
c. Efficient reproductive structure
1. Produce gametes, place to unite & form seed, meiosis and fertilization can occur
4. Pollination
a. Plants cannot move so they produce moving parts to reproduce
b. Pollen from stamen lands on female stigma
c. Pollinators only go to certain plants
1. Bees è red flowers
2. Odors
3. Shaped so non-pollinators cannot reach nectar or pollen
4. Wind pollinated flowers è small, no petals, do not produce nectar
1. Dermal Tissue è protective covering
a. Cuticle which prevents water loss and infection
b. Secondary growth è cork replaces cuticle
2. Vascular tissue (transport thru plant)
a. Xylem
1. Dead hollow cells form channel
2. Transport upwards
3. Hard walls (support)
b. Phloem
1. Sugar from where it was made to non-photosynthetic parts
2. Cells are softer than xylem, living
Plant Growth
1. Meristem è specialized part of the plant that has unspecialized cells that divide continuously, later specialize
a. Apical meristem
i.Tips of roots and shoots
ii. Primary growth
iii. Primary tissue
b. Lateral meristem
i.Found in vascular and cork cambium
ii. Secondary growth (increase diameter)
Plant Systems
1. Root System (below)
2. Shoot System (above ground)
Root System
1. Purpose
a. Collect water/nutrients
b. Anchor
c. Food storage
2. Types
a. Taproot
b. Fibrous root
3. Structure
a. Division
b. Elongation
c. Maturation
d. Root cap
4. Primary Growth - Root Tissues
a. Epidermis è protects root, root hairs that take up water
b. Cortex è food storage
c. Endodermis è controls which minerals/nutrients enter vascular system
d. Pericycle è meristem tissue which forms vascular and cork cambium in 2ndary growth
e. Vascular cambiam è produces phloem to the outside, xylem to the inside
5. Secondary Growth - Root Tissues
a. Caused by vascular cambiam
b. Cells divide and produce secondary xylem or secondary phloem
c. Secondary xylem becomes wood.
Shoot System
1. Purpose
a. Provide support
b. Position leaves in sunlight for photosynthesis
c. Flowers/fruit for reproduction
2. Types
a. Woody stems (vines, shrubs, confers, dicot trees)
b. Herbaceous (usually less than 1 m tall è weeds, cabbage, lettuce)
3. Stems start as bud (may elongate to form lateral branches)
a. Terminal buds at shoot tips (primary growth)
b. Lateral buds located in nodes along stem (new branches/leaves)
4. Bark
a. Tissues composed of cork, cork cambium, cortex and phloem
b. Beneath the bark, is the secondary xylem (aka wood)
i.Hardwood
ii. Sapwood
1. Center of photosynthesis
2. Network of veins (continued from phloem and xylem in stem)
3. Petiole (leaf stalk)
4. Epidermis
a. Top and bottom
b. Cuticle
5. Stomata
a. Lower side
b. Guard cells
6. Mesophyll
a. Main site of photosynthesis
b. 2 types of cells
i.
ii. Palisade (long, narrow, upper layer of leaf)
iii. Spongy mesophyll (loosely packed, air spaces to allow efficient exchange of gases)