Bio plants cheat sheet
Biological Organization of Plants
Cells: Basic units of life in plants with unique features like cell wall, chloroplasts, and large central vacuole.
Tissues: Plant cells form dermal, ground, and vascular tissues for protection, support, photosynthesis, and transport.
Organs: Roots anchor, absorb water and nutrients. Stems support and transport. Leaves perform photosynthesis and gas exchange.
Organ Systems: Shoot system (stems, leaves, flowers) for photosynthesis, reproduction, and support. Root system for absorption, anchoring, and storage.
Plant Growth: Indeterminate growth through meristems, undifferentiated cells dividing into specialized tissues.
Reproduction: Sexual (gamete fusion to form seeds) and asexual (offspring without gametes) reproduction methods.
Life Cycle: Alternation of generations with haploid gametophyte producing gametes and diploid sporophyte producing spores for new gametophytes.
Plant Organs and their Functions
1. Roots: Anchoring: Provide support and stability to the plant. Absorption: Absorb water and nutrients from the soil. Storage: Store nutrients and carbohydrates.
2. Stems: Support: Provide structural support to the plant. Transport: Conduct water, nutrients, and sugars between roots and leaves. Photosynthesis: Some stems can carry out limited photosynthesis.
3. Leaves: Photosynthesis: Main site of photosynthesis, converting sunlight into energy. Gas Exchange: Exchange of oxygen and carbon dioxide with the atmosphere through tiny pores called stomata. Transpiration: Loss of water vapor through stomata, which helps in the transport of water and nutrients.
4. Flowers: Reproduction: Produce reproductive structures such as male stamens (anther and filament) and female pistil (stigma, style, and ovary). Pollination: Transfer of pollen from male to female parts for fertilization. Seed Production: After fertilization, flowers develop into fruits that contain seeds.
5. Fruits: Seed Dispersal: Fruits help in the dispersal of seeds to new locations. Protection: Provide protection to seeds from physical damage and harsh environments. Nutrition: Some fruits provide a nutritious food source for animals, encouraging seed dispersal.
6. Seeds: Reproduction: Contain embryonic plant structures necessary for new plant growth. Dormancy: Seeds can remain dormant until favorable conditions for germination are present. Food Storage: Store nutrients to support initial growth until the seedling can photosynthesize.
Plant Kingdom and Plant Anatomy
1. Plant Kingdom: Plantae (multicellular, eukaryotic plants)
2. Plant Divisions: a. Bryophytes: Non-vascular plants (mosses, liverworts, hornworts) b. Pteridophytes: Vascular plants, reproduce via spores (ferns, horsetails) c. Gymnosperms: Vascular plants, “naked” seeds in cones (conifers, cycads, ginkgoes) d. Angiosperms: Vascular plants, flowers and fruits, seeds enclosed in fruits (flowering plants)
3. Angiosperm Classification: a. Monocots: Single cotyledon, parallel leaf veins, flower parts in multiples of three (grasses, lilies, orchids) b. Dicots: Two cotyledons, net-like leaf veins, flower parts in multiples of four or five (roses, sunflowers, oak trees)
4. Plant Parts: a. Roots: Anchoring, absorption of water and nutrients (taproot, fibrous root) b. Stems: Support, transportation (herbaceous, woody) c. Leaves: Photosynthesis, gas exchange (blade, petiole) d. Flowers: Reproduction, attracting pollinators (petals, sepals, stamens, carpels/pistils)
5. Plant Reproduction: a. Asexual Reproduction: Vegetative propagation, rapid and identical offspring b. Sexual Reproduction: Pollination (transfer of pollen), fertilization (fusion of gametes)
Factors Affecting Plant Growth
1. Light: Intensity, duration, and quality affect plant growth.
2. Water: Adequate amount for hydration and nutrient uptake.
3. Temperature: Optimal range for growth; extremes are detrimental.
4. Nutrients: Macronutrients and micronutrients from soil or fertilizers.
5. Soil: Composition, drainage, pH, and texture impact growth.
6. Air: Circulation for gas exchange during photosynthesis and respiration.
7. Genetics: Species and genetic makeup determine growth characteristics.
8. Hormones: Regulate growth processes like cell elongation and flowering.
Plant Transport and Hormones.1. Plant Transport: Xylem: Water and mineral transport. Phloem: Sugar and nutrient transport.
2. Water Transport: Transpiration: Loss of water through leaves. Cohesion-Tension Theory: Water pulled up due to cohesion and tension.
3. Xylem: Vessels: Tubular structures for water transport. Tracheids: Elongated cells for water transport.
4.Translocation: Phloem Loading: Active transport of sugars. Pressure Flow Hypothesis: Sugars move in phloem by pressure.
5. Stomata: Openings for gas exchange and transpiration. Guard Cells: Control stomata opening.
6. Factors Affecting Transpiration: Light, temperature, humidity, and wind.
7.Adaptations: Root hairs: Increase absorption. Casparian Strip: Controls water movement. Xerophytes: Adapted to arid conditions.
8. Plant Hormones: Auxins: Cell elongation and tropisms. Gibberellins: Growth, germination, and flowering. Cytokinins: Cell division and aging. ABA: Growth inhibition and stomatal closure. Ethylene: Fruit ripening and senescence.