Plants Read pg 398-420, 470-489 HW 418 #1-18 HW 492 #1-20, 26 Fruit homework (you’ll see)
Characteristics • Most plants are green due to their chlorophyll. • All contain cell walls made of cellulose. • Plants are autotrophic, producing their own energy from sunlight. • 2 major categories: • Gymnosperms: early seed plants, flowerless • Angiosperms: flowering plants
Reviewing cell anatomy • Unique parts: • Cellulose cell wall • Large vacuole • chloroplasts
Evolution • BryophytesSeedless vascular plantsgymnospermsangiosperms • Bryophytes are small leafy or flat plants that are evolutionarily the transition between green algae to vascular plants • Ex: some mosses • Seedless vascular plants are mainly roots & shoots • Ex: Ferns • Gymnosperms produce seeds • Ex: Conifer trees (pine trees)
Gross Anatomy • Major tissues in plants: • Roots, stems, leaves, and sometimes flowers • Xylem and phloem • Xylem transports water along a plant stem • Phloem transports foods/nutrients • Stoma • Specialized cells in leaves that open and close to allow gas exchange.
Shoots & Roots • Roots • Anchor • Uptake water and minerals/nutrients • 2 types: Tap roots, fibrous roots • Stems • Where shoots and buds arise from. Lateral and vertical expansion of the plant. • Provides support and transfers uptake from roots to the rest of the plant. • Leaves • Main food production. Broad structures capture sunlight. • Often waxy to prevent water loss. • Flowers are considered specialized shoots.
Seeds • What is a seed? • A seed is a mature ovule containing an embryo. • Gymnosperm means “naked seed” and these are the first plants to produce seeds evolutionarily. • Pollination is the transference of a male gametophyte (pollen) to a female gametophyte (ovule) and fertilization results in a seed.
Flowering plants • Angiosperms belong to the phylum Anthophyta. • Split into two major categories: monocots and eudicots. • Fruits and seeds use a variety of dispersion methods: • Animals • Water • wind
Monocot vs Dicot • Monocots are plants with one cotyledon (or seed-leaf), triplet flowers, and parallel veins. • Good examples of monocots are: • Grasses • True grains (rice, wheat, corn) • Palm trees, banana trees • Onion family (onion and garlic • Eudicots are plants with 2 (di=two) cotyledons, flowers in multiples of 4/5, and branched veins. • Most other flowering plants are eudicots.
2 phase life cycle • All plants undergo an alternation of generations. • A switch from diploid (2n) generation to haploid (n) generation where structures differ.
Life Spans • Another way to classify plants is the length of time they live: • Annuals: Plants that live and die in one year or growing season. Most vegetables and flowers are annuals. • Biennials: These plants complete a lifecycle in 2 years. Carrots, beats, and some flowers are biennials. • Perennials: These plants continue to grow year after year. Trees are good examples of perennial plants.
Fruits! • 1. apples,2. oranges,3. peaches,4. bananas,5. berries - i.e. strawberries, raspberries, blueberries, etc.6. pears7. any fruit not listedextras -kiwis, cantaloupes, melons, papayas, pineapples, red/green peppers, avocados
Other things: • Plant defense • Special structures (thorns etc) • Hormones • Flower structure • Plant diversity • Fruit • Agriculture/human benefits