Transcript Inv. 5 Seeds of Life

Inv. 5 Seeds of Life
FOSS 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 cotyledon
 Dicots: 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:
Multiple of 3
Dicots:
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.