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.