Transcript seed
22.3 Seed Plants What are seeds? Every seed contains a living plant ready to sprout as soon as it encounters the proper conditions for growth. Seed Parts Seeds allow plants to reproduce without water. Parts Seed Coat - protects the embryo Cotyledon - inside seed, used to absorb food from endosperm for the developing plant embryo Monocots (1 cotyledon) vs. Dicots (2 cotyledons) Embryo- baby plant; has tiny root, stem and cotyledons (develop into leaves) Endosperm – built in food supply for the seed. Germination of Seeds Germination - development of embryo inside seed into a new plant with proper environment. Seed Dispersal Movement of seeds for germination By wind, water, animals eating fruits and depositing seeds or carrying seeds on fur Types of Seed Producing Plants Gymnosperms Angiosperms Gymnosperms Plants that produce “Naked” seeds (exposed on the scales of cones) can reproduce without free-standing water, via pollination – ADAPTATIONS – Seeds (embryo & food supply) – seeds allow plants to disperse to new places Gymnosperms do have naked seeds (not enclosed by a fruit). CONIFERS CYCADS GINKGOS Angiosperms (Flowering Plants) – Adaptations: – Vascular tissue – Flowers (reproductive structure) – Seeds develop within ovaries – Fruit - ripened ovary Vascular Plant Crash Course Pollen In seed producing plants: Male gamete is called a pollen grain. Pollen grains are carried wind or animals to the female reproductive structure = pollination. Pollination Pollination - is the transfer of pollen from the male reproductive structure to the female reproductive structure. Types of Pollination Wind or animals. Wind is far less efficient – So these plants rely on high a volume of pollen to ensure pollination. Structure of a Flower Structure of a Flower There are both male and female parts in flowers!! Female Part = Pistil – Includes three parts: stigma, style, and ovary Stigma – sticky surface at the top of the pistil; traps and holds the pollen Style – tube-like structure that holds up the stigma Ovary – has the seeds inside and turns into the part of fruit that we eat Ovule – part of the ovary that becomes the seed . Structure of a Flower Male Part = Stamen – Includes two parts: the anther and filament. Anther – part of the stamen that is located at the end of the filament. produces/contains pollen Filament – Part of the stamen that supports the anther Pollen Grain – Produced in the anther. Is the male gamete in flowers. Sepal – Protected the flower when it was in bud Petal – Attract pollinators The Structure of Flowers Flower Structure Sepals and Petals Flower Structure Stamens = filament and anther Anthers – produce pollen grains Flower Structure Pistil = Stigma, Style, and Ovary Ovules – located inside the ovary – develop into seeds after pollination. Perfect Vs. Imperfect Flowers Two Classes of Angiosperms Monocot & Dicot Monocots and Dicots lily Oak tree grass Cherry Tree