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). CYCADS CONIFERS 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

 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

lilygrassOak treeCherry Tree Monocots and Dicots