PLANTS - Socorro Independent School District

PLANTS 9 Biology Plant Anatomy Leaves: photosynthesis and transpiration Stem: support, transport of H2O and sugar Roots: anchor, and absorb H2O and minerals Flower: contains

reproductive parts of plant Roots Root hairs: increase surface area to increase absorption Nodules: symbiotic relationship with fungi/ bacteria for nitrogen

fixation Sometimes sugar storage: potato, carrot, turnip, onion, garlic Stems Vascular bundles: xylem (water transport) and phloem( sugar transport)

Cambium: sometimes bark, sometimes herbacious Leaves Waxy cuticle: waterproof Upper epidermis: chloroplasts Spongy mesophyll: H2O, sugar, O2 storage

Lower epidermis: stomata controlled by guard cells, open to release O2 (atmosphere), H2O (transpiration), take in CO2(photosynthesis) Angiosperms and Gymnosperms Angiosperm- flowering plants, have a coated

seed Gymnosperms- conifers (pine trees), naked seed Monocots and Dicots Monocots and Dicots differ in the following ways: Leaf venation

Vascular tissue arrangement Number of flower petals Root arrangement Meristematic Tissue Meristematic tissue: stem cell tissue of the plant

Apical meristematic tissue: helps stem grow up and roots grow down Lateral meristematic tissue: helps stem(trunk) increase in girth Ground Tissue Parenchyma: storage and photosynthesis

Collenchema: support and flexibility Sclerenchyma: all deadsupport and vessel elements wood pulp Plant Hormones Auxins- IAA, causes plants to grow to the light (phototropism) Gibberelin- helps with

plant growth and seed germination Ethylene- only gas hormone, helps with ripening Tropisms Phototropism- plants grow to light Gravitropism- plants

grow in response to gravity Thigmotropism- plants respond to touch (Venus Flytrap, tendrils on vines) Angiosperm Reproduction Female parts are the carpel: stigma, style and ovary

Male parts are the stamen: the filament and anther, pollen STEPS: 1. Pollen lands on the stigma 2. Nucleus in pollen creates a pollen tube to reach ovule 3. Pollen fertilizes ovule to create a zygote (seed)

Fertilization Self-fertilization decreases genetic fitness of plant species Pollination accomplished by insects, birds and animals