Plants: 101 The Basics By: Laura Schaefer Introduction In this presentation, you will learn the basics of plants. This includes, but is not limited to: Plant parts Function of each part And the differences between plants, monocots vs. dicots The Seed Seeds are Vital to Life Though they come in different shapes and sizes, seeds contribute to the most basic of necessities of life. They grow into plants which: provides food and energy for herbivores converts carbon dioxide into oxygen supplies shelter What is a seed? A seed is the result of plant reproduction. It forms when the pollen from a male flower merges with an ovule from a female flower through a process known as pollination. This process is also what causes many of us to sneeze in the spring and summer months. Did you know? Seeds can range in size from being as small as a pin head to as large as a basket ball! Disclaimer *Please note: although somewhat similar, the following seed and seedling sections are in reference to a dicotyledonous plant and does not represent the monocotyledonous plant species. Seed Stucture Seed Structure Seed coat- protects the seed. Hilum- point of attachment to the ovary Cotyledon- the "food supply" for the growing embryo until the root can supply enough nutrients to support the growing plant Embryo- made of two parts: First true leaf- the first part of the growing seedling to go through photosynthesis Root- perhaps the most important part for the growing seedling, the root supplies the rest of the plant with vital nutrients *Please note: this is a bean seed. Not all seeds look this way! The Young Seeding The Growing Up Process As the seed is transforming into a full grown plant, several changes take place. When introduced to a damp planting medium, the cotyledons absorb water and swell, causing the seed coat to break open. The root and lower part of the stem (below the cotyledons) begin to elongate. The stem starts to form in the shape of an upside-down U Once the growing stem reaches the surface and is exposed to light, it straightens out, and the cotyledons are pulled above the surface. Now that the cotyledons are above the surface, they turn green and begin photosynthesis. By this point, the root has formed enough to supply the seedling with the water and nutrients it needs to grow. The Growing Up Process Continued The stem above the cotyledons begins to elongate and the first true leaf grows. When it grows enough, the leaf takes over the task of photosynthesizing No longer needed, the cotyledons dry up and fall off. The plant continues to grow new leaves, getting taller and stronger everyday. Monocot Vs. Dicot How to Tell the Difference Monocot seedling Cotyledon remains below soil Dicot seedling Cotyledons rise above the soil How to Tell the Difference Monocot leaf (ie corn, grass) Parallel veins Dicot leaf (ie trees, tomato) Branched veins Have you been paying attention? True or False? The seedling photosynthesizes before emerging above the surface. False. It isnt until after emerging above surface that the young seedling begins using the suns rays to create the energy it needs for growth and gas exchange. True or False? In plants of the monocotyledonous family, the veins in the leaves are constructed of a branched network. False. The system of veins within the monocotyledon family runs parallel to the edge of the leaf. The veins never touch. Remember, mono means single, and each vein works independent of each other in this situation. True or False? The roots aid in transporting vital nutrients and moisture to the growing and adult plant. True! Without a root system, a plant will struggle to survive. In some cases, a plant can survive for a short time, and in rare cases, if the conditions are right, the plant can learn to adapt.