22.3 seed plants. what are seeds? every seed contains a living plant ready to sprout as soon as it...
TRANSCRIPT
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 DispersalMovement 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
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
lily
grass
Oak tree
Cherry Tree
Monocots and Dicots