What are the spermatophytes Seed Plants What are the basic characteristics shared by all seed plants Produce seeds Haplodiplontic life cycle Heterosporous produce 2 types sizes of spores megaspores microspores 2 types of sporangia megasporangia microsporangia Spores not dispersed retained on body of sporophyte Fertilization takes place on gametophyte as always Megagametophyte female gametophyte protected in ovule on sporophyte Developing embryo nourished protected within megagametophyte Therefore embryo develops on sporophyte Gametophytes develop within sporangia on sporophyte Gametophytes reduced in size not dominant size from 2 cells to 2000 cells vs billions of cells in adult sporophyte Gametophytes dependent on sporophyte for nutrition protection Sporophyte dominant nutritionally independent Fertilization takes place on gametophyte as always Megagametophyte female gametophyte protected in ovule on sporophyte Developing embryo nourished protected within megagametophyte Therefore embryo develops on sporophyte What does it mean that spores are not dispersed in seed plants retained on body of sporophyte Define the term heterospory How has heterospory been advantageous in adaptation to life on land in seed plants Heterospory is the productionof two different types of spores by a plan Megaspores few produced within megasporangia on megasporophylls Megasporangia are within ovules Megaspore develops into megagametophyte Microspores many produced within microsporangia on microsporophylls Microspore develops into Microgametophyte Heterospory Spores are not dispersed away from parent sporophyte in seed plants cf mosses ferns Microgametophytes are within pollen grains protected by sporopollenin coating Pollen grain enables internal fertilization water not required for fertilization Much greater protection of gametophytes Much greater protection of young sporophytes embryos protected in seeds Explain the general pattern of pollen development in seed plants Microsporocyte produces 4 microspores via meiosis Microspores covered with sporopollenin Microspore divides by mitosis to form microgametophyte Microgametophyte size 4 cells in pines 2 cells in angiosperms lack antheridia Sporopollenin protects microgametophyte from desiccation UVR damage Pollen eliminates the need for water for fertilization enables seed plants to grow in arid areas Pollination transfer of pollen from microsporangium to the part of the plant containing the ovules Pollen Chemical cues stimulate pollen grains to germinate pollen tube grows Non flagellated sperm develop within pollen tube Sperm delivered internally to egg within megagametophyte Pollen Microsporocyte 2n meiosis 4 Microspores n mitosis Immature Pollen Grain with tube cell generative cell pollination Pollen tube forms 2 sperm cells travel to ovule fertilization What is the relationship between pollen and the microgametophyte Pollen is the microgametophyte in seed plants just in a protective package Pollen is the protective structure that contains and transports the microgametophyte which is the male gametophyte in seed plants What is sporopollenin What advantages does it provide Microspores covered with sporopollenin Sporopollenin protects microgametophyte from desiccation UVR damage Pollen Define pollination in a way that applies to all seed plants Pollination is the transfer of pollen from the male reproductive structure anther in angiosperms male cone in gymnosperms to the female reproductive structure stigma in angiosperms ovule in gymnosperms in seed plants allowing fertilization to occur Define pollination in a way that applies to angiosperms only Pollination in angiosperms is the transfer of pollen from the anther of a flower to the stigma of the same or a different flower enabling What is the function of pollen The primary function of pollen is to transport and protect the male gametophyte microgametophyte which produces sperm cells needed for fertilization in seed plants Contrast the processes of pollination and fertilization See lab Pollination is the transfer of pollen fertilization is the actual fusion of gametes Pollination must happen first for fertilization to occur Explain how pollen is an adaptation to life on land Seed contains embryo nutrition for embryo Nutrition powers embryo growth when seed germinates Embryo in seed is dormant in state of arrested development Embryo resumes growth at germination mature sporophyte Seed coat wall of protection around embryo seed contents Nutrition powers growth of seedling from below ground Germination growth of organism from a seed or spore also applied to pollen What are the basic structural difference between pine pollen and angiosperm pollen Pine pollen is designed for wind travel it s winged and simple Angiosperm pollen is more diverse its structure is adapted to how the plant pollinates wind insects birds etc What advantages do seeds provide to sporophyte embryos Seed contains embryo nutrition for embryo Nutrition powers embryo growth when seed germinates Seed coat wall of protection around embryo seed contents What does it mean that a fertilized ovule becomes a seed When an ovule is fertilized it undergoes a transformation developing into a seed which contains the next generation of the plant This process ensures embryo protection nourishment and dispersal for new plant growth What advantages do seeds provide to life on land Seed contains embryo nutrition for embryo Nutrition powers embryo growth when seed germinates Embryo in seed is dormant in state of arrested development Embryo resumes growth at germination mature sporophyte Seed coat wall of protection around embryo seed contents Nutrition powers growth of seedling from below ground Germination growth of organism from a seed or spore also applied to pollen Contrast the nutrition contained in the seed for the germinating embryo in gymnosperms and angiosperms including ploidy In gymnosperms the embryo feeds on haploid female gametophyte tissue prepared before fertilization In angiosperms the embryo is nourished by triploid endosperm which forms after fertilization through double fertilization Contrast the structures and ploidies of structures present in a mature ovule one in which there is a megagametophyte but before fertilization in gymnosperms and angiosperms Describe what it means for the following to germinate spore pollen grain seed Spore germination leads to a haploid gametophyte Pollen grain germination enables sperm transport via a