Plants
What Is a Plant?
Types, Structures, Functions and Adaptations
Plants
• A plant is:
• multicellular
• eukaryotic
• Most produce their own food
• Have thick cell walls of cellulose
Plant Types
Plants
Vascular
Non Vascular
Vascular
Vascular
seeded
non-seeded
Gymnosperms
Angiosperms
Plant Types
• Non Vascular
– only have cell walls to provide support, so
they are small, low plants.
– lacks roots, true leaves, and stems **
Plant Types: nonvascular
– produce spores
– Live and depend on moist environments
• Reproduction and Survival
– mosses, liverworts and hornworts.
Plant Types
• Vascular – “veins”
– Two Major Groups:
• Seedless Vascular Plants
• Vascular Seed Plants
– Vascular tissues transports food/water
• Xylem - transports water and minerals
• Phloem - transports food/nutrients
Plant Types: vascular
• Seedless
– Have a vascular system
– reproduce only by SPORES
– Leaves are called fronds
Plant Types: vascular
• Seeded
– have vascular tissue, use seed to reproduce
and have leaves, stems and roots.
– Seeds allow for greater reproductive success
Embryo
Food Supply
Seed Coat
Plant Types: vascular/seeded
Gymnosperms
- “naked seed”
- seeds NOT protected by fruit
Conifers
- Cone-bearing plants
- Cones are either male or female
- Largest and most diverse group of
gymnosperms
• Most are evergreen
Plant Types: vascular/seeded
• Angiosperms
– Flowering plants
– produce seeds enclosed within a fruit.
- Produce fruits with 1 or more seeds
- Fruit aid in seed dispersal
Plant Types
• Angiosperms
– 2 types: determined by the number of
cotyledons
• Monocot—one seed leaf
–Ex. Corn, grass
• Dicot—two seed leaves
–Ex: Trees, shrubs, sunflowers, most flowers
Plant Types
• Monocot:
– Petals in multiples of 3
– Parallel network of veins
– vascular bundles scattered throughout the stem.
– Ex: grasses, orchids, lilies, and palms.
Plant Types
• Dicots
– Network of veins
– Petals of multiples of 4 or 5
– Most shrubs and trees (except conifers), cacti,
wildflowers, garden flowers, vegetables, and
herbs.
–vascular bundles that form a ring
Plant Structures and Adaptation
– Roots
– Stems
– Leaves
– Cuticles
– Seeds / Reproduction
Plant Structures and Adaptations
• Roots - structures that allow plants to obtain
water/nutrients from soil
– Tap
- prop
– Fibrous
- aerial
Plant Structures and Adaptations
• Stems - provides support for growth and food
storage.
– Xylem and phloem
Plant Structures and Adaptations
• Protection and Reproduction
– Cuticles - waxy coating on the outside of
plant that prevents water loss
– Seeds/spores -keep reproductive cells from
drying out
Plant Structures and Adaptations
• Tissue
– Stomata: controls the exchange of gases,
and water loss
– Guard cells: control the opening and closing
of stomata.
Plant Structures and Adaptations
• Leaves - structural adaptations for functions
– release irritants
– Cactus spines are modified leaves that help
reduce water loss and provide protection
Plant Structures and Adaptations
– Carnivorous plants - have leaves with
adaptations that can trap insects or other
small animals.
• grow in places where the soil is thin or
poor in nutrients
–Pitcher plant, Venus fly trap
Plant Structures and Adaptations
• Course flower – in full
bloom gives off an odor
of rotting flesh. Attracts
pollinators; flies and
beetles.
Plants
• Flowers
"What's in a name? That which we call a rose
By any other name would smell as sweet."
Romeo and Juliet (II, ii, 1-2)
Plants
– Angiosperms
• Flowering; seeds enclosed in a fruit
• contains the reproductive structures that the fruit
develops from.
• Flowers are reproductive structures for angiosperms