Plant Development

• VEGETATIVE REPRODUCTION - form of asexual reproduction; new plants grow from parts of existing plants
• ALTERNATION OF GENERATIONS - haploid (gametophyte) and diploid (sporophyte) stages alternate
• SPOROPHYTE STAGE - produces haploid spores through meiosis
• haploid spores undergo mitosis to become the diploid gametophyte
• GAMETOPHYTE STAGE - produce gametes by mitotic division
• haploid gametes fuse into a zygote and undergo mitosis to become the diploid
• male gametophyte: pollen
• female gametophyte: ovule
• DOUBLE FERTILIZATION - a feature unique to angiosperms
• in double fertilization, pollen is composed of → pollen tube cell and generative cell (form two sperm cells)
• . one sperm cell + egg = diploid zygote
• one sperm cell + two polar nuclei = endosperm
• EMBRYOGENESIS - zygote undergoes mitosis → produces proembryo and suspensor (anchors proembryo and transfers nutrients from parent)
• ovule → becomes seed
• ovary → becomes fruit
• SEED GERMINATION - the embryo develops into a new sporophyte
• embryonic root – first organ to emerge from germinating seed
• shoot tip – emerges next out of the soil