Inv. 5 Seeds of LifeFOSS Diversity of Life Grade 7
Parts of a Seed
Seed Coat: the outside of the seed is a tough, almost airtight covering.
Embryo: the baby plant
Cotyledons: starchy supply of endosperm.
Germination
Germination: the resumption of growth and development of the new plant in a seed.
Initiated by water: Water softens the seed coat, allowing
water to enter the seed. Cotyledons soak up water and swell,
causing the seed coat to split allowing the embryo to resume growth and development.
Germination
The starch of the cotyledon provides the energy during the early stages of plant growth. Monocots: one cotyledonDicots: two cotyledon
Germination
Energy-rich oils and starches stored in the cotyledon are converted into sugars, which nourish the developing young sprout as it grows, differentiates, and develops new structures above and below the soil surface.
Role of Photosynthesis
Photosynthesis captures solar energy and converts it into chemical compounds that are food for the plant.
The chemical compounds (sugars and starches) are either used by the plant right away or stored in the cotyledons to launch the next generation of plants.
Gymnosperms
A gymnosperm is a vascular plant that produces
seeds lacking an outer fruit. Normally these
seeds are contained in cones.
Gymnosperms have male and female cones.
The male cones produce sperm, which are
contained in pollen grains. Male cones are
normally smaller than female cones.
Male Gymnosperm
Female Gymnosperm
The female cones produce eggs, which are
contained in ovules. Female cones have a
sticky resin that “catches” the pollen released by
the male cone.
When fertilized, the female cone enlarges and
the scales separate. This separation
allows the seeds to drop out of the cone and are dispersed
by animals, such as chipmunks & squirrels.
Female Gymnosperm
Angiosperms
Angiosperms are flowering plants that reproduce through seeds that are contained in fruit.
Angiosperms are broken into 2 groups: the monocots and the dicots.
Monocots
Examples of Monocots
Grasses Corn
Dicots
Examples of Dicots
Magnolia
Roses
Monocot vs. Dicot
Flowering Plants
Monocots: Dicots:
Multiple of 3 Multiples of 4 or 5
Monocots vs. Dicots
Leaves
Parallel Leaf Venation Pinnate Leaf Venation
Monocots vs. Dicots
Roots
Diffuse Roots Tap Roots
Types of Monocots and Dicots
Roots
Keeps the plant in place
The reaching and the probing of roots is to increase the plant’s access to water.
First part of the seed is the root.