Plant Growth and Development Seeds Flowers Fruits Seeds

Plant Growth and Development Seeds Flowers Fruits

Seeds Start it All • Seed contain embryos that form into new plants. • Seeds can stay dormant for 1000’s of yrs. • Favorable conditions or damage to a seed coat start growth

Some seeds • • Need light exposure Soil moisture Perfect temperature Or any environmental change that can spark rapid growth. • Damage to seed coat through…. – Fire – Passing through the digestive tract of animals – Falling on a rock – Once the damage is done the seed must fill up with enough water and oxygen to grow

Monocot seed growth vs. dicot

Seed Parts •

Seed parts continued • Monocot– Seed coat for protection – Radicle is the embryonic root – Plumule is the embryonic leaf – Endospermis nutrition – 1 cotyledon (seed leaf) • Dicot – – – Seed coat (protect) Radicle (root) Hypocotyl (stem) Epicotyl (leaf) 2 cotyledons (seed leaves for primary nutrients to embryo) – Endosperm matured into cotyledons

Fertilization of seedless plants • Zygote develops into sporophyte • Spores develop into gametophytes • Antheridia (male) • Archegonia (female) • Male swim to female • Zygote is formed

Fertilization of Gymnosperms • Immature seed cone (female) • Pollen cone (male) • Gametophytes • Female + male = zygote • Pine seed with wing is the zygote (sporophyte)

Fertilization of Angiosperms • Pollen (male) from the anther (gametophyte) • Ovule (female) from the ovary (gametophyte) • Pollination = zygote • Zygote = seed • Flower becomes a fruit.

Flower parts • Petals attract pollinators • Sepal protects the flower • Stamen is the male reproductive organ • Filament holds anther which contains pollen • Pistil is female organ that has stigma to catch pollen to send down pollen tube to ovary (ovule)

Growing without seeds • It’s called vegetative reproduction and occurs with roots stems or leaves. • Helps allow plants to cover areas faster • 100’s and 1000’s from one single plant • Examples include: runners (bermuda grass), bulb (onion or tulip), Corm (gladiolus), Rhizome (Fern), Tuber (potato)

Runner • Horizontal above ground stem that helps the plant spread within an area.

Bulb • Very short stem with thick fleshy leaves

Corm • Very short thick underground stem with thin scaly leaves

Rhizome • Horizontal underground stem

Tuber • Swollen fleshy underground stem