seed structure

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  • 1. Notes:Seeds

2. What is a seed? A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. The formation of the seed completes theprocess of reproduction in seed plants. 3. Why are seeds advantageous for plants? maintain dormancy until betterenvironmental conditions arise afford protection to young plant atvulnerable developmental stage contain adequate food supply untilphotosynthesis is possible dispersal of plants 4. SEED STRUCTURE External Seed coat (testa) Hilum Embryo Cotyledon Epicotyl / Hypocotyl Pumule Radical 5. Seed Coat AKA testa The seed coat protects the embryo Can be of varying thicknesses, dependingon the seed type. 6. Hilum Scar from the seed being attached to theparent plant 7. Embryo The embryo is what forms the new plantonce the opportune conditions arepresent. 8. Cotyledon The cotyledon is the firstleaf that germinates. It is filled with storedfood that the plant usesbefore it beginsphotosynthesis. Some plants have 1cotyledon (monocot)and some have 2cotyledons (dicot). 9. Epicotyl /Hypocotyl The basis for theplants stem. It is known as theepicotyl above thecotyledon and ahypocotyl below thecotyledon. These grow upwardin response to light. 10. PlumuleThe shoot tip with a pair of miniature leaves. 11. The Radicle The part of the seed where the rootdevelops. 12. SEED STRUCTURE Seed coat (testa) Embryo Cotyledon Epicotyl / Hypocotyl Pumule Radical 13. SEED DISSECTION MATERIALS Soaked pinto seed Dissecting microscope Tweezers Ruler 14. SEED DISSECTIONEXTERNAL INTERNAL Draw the external pinto Carefully remove the seedbeancoat. Label structures from Gently pull apart the twonotes halves of the seed. Examine each half with thedissecting microscope Draw what you see insidethe bean Label structures from notesREVIEW THE RULES FOR LAB DRAWING IN YOUR STUDENT GUIDEBE SURE YOU MEASURE AND RECORD THE LENGTH OF YOUR SEED 15. Plumule Epic y HypocottyllEmbryo Cotyledon Radicle