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
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
 Plants that produce “Naked” seeds (exposed on the scales
of cones)
 can reproduce without free-standing water, via
– Seeds (embryo & food supply)
– seeds allow plants to disperse to new places
Gymnosperms do have naked seeds (not
enclosed by a fruit).
Angiosperms (Flowering Plants)
– Adaptations:
– Vascular tissue
– Flowers (reproductive
– Seeds develop within
– Fruit - ripened ovary
Vascular Plant Crash Course
 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 - is the transfer of pollen from the male
reproductive structure to the female reproductive
 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
 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
 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
 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
Oak tree
Cherry Tree