3.2 Most Mosses and Ferns live in moist environments.
|
Evidence indicates that life first appeared on Earth about 3.8 billion years ago. Tiny single-celled and multicellular organisms lived in watery enviromnets such as warm shallow seas. Fossil evidence suggests that plant life did not appear on land until about 475 million years ago.
|
Life on Land
As the pond dried up a few organisms were stranded and were able to survive on land. Life on land is very different than life in the water. The first plants needed to be able to get both nutrients and water from the land.
|
Benefits of Life on Land
Plants on land had two huge benefits that plants in the water didn't have. Unlimited access to carbon dioxide in the air and direct sunlight.
|
MOSSES and FERNS
Among the first plants to live on Earth were the ancestors of the mosses and ferns you see today. Both probably evolved from species of algae that lived in the sea and in fresh water. Mosses are more simple in structure than ferns. Mosses, and two closely related groups of plants known as liverworts and hornworts are descended from the first plants to spread onto the bare rock and soil of Earth. Ferns and their relatives appear later.
|
MOSSES ARE NONVASCULAR PLANTS
Mosses Reproduce with Spores
|
Mosses are nonvascular plants. Nonvascular plants do not have vascular tissue. Water and nutrients simply move through the bodies cell by cell. Moss plants have adaptations for life on land. For example, each moss cell, like all plant cells, is surrounded by a thick wall that provides it with support. Moss cells also have special storage areas for water and Nutrients.
Mosses do not grow very large but they do have simple roots, stems and leaves. These adaptations help moss plants survive on land while algae survived only in water. Mosses, Ferns and Fungi all reproduce with spores. Spores are an important adaptation that allowed the ancestors of these organisms to reproduce on land. A spore is a single reproductive cell that is protected by a hard, watertight covering. The covering prevents the cell from drying out. Spores are small and can be transported through the air. This means offspring from spores can grow in places that are distant from the parent organism.
Within a clump of moss are both male and female reproductive structures (first generation). When conditions are right, these structures produce sperm and eggs. Fertilization can occur only if water is present because the tiny moss sperm move by swimming. |
Use the drawing below to label your moss on your foldable.
Other Characteristics of Moss:
Grow in only moist areas
outer waxy covering to prevent water loss
root like structure called rhizoids to anchor the plant. These do not absorb water.
some can survive short dry spells
water moves cell by cell
sperm must swim to egg
Grow in only moist areas
outer waxy covering to prevent water loss
root like structure called rhizoids to anchor the plant. These do not absorb water.
some can survive short dry spells
water moves cell by cell
sperm must swim to egg
Benefits of Moss
help decompose dead wood
serve as pioneer plants on bare rock or ground
help prevent erosion
provide shelter for insects and small animals
used as nesting material by birds
peat moss is burned as fuel
help decompose dead wood
serve as pioneer plants on bare rock or ground
help prevent erosion
provide shelter for insects and small animals
used as nesting material by birds
peat moss is burned as fuel
Sphagnum moss is a cash crop in Wisconsin. Find out all you can about this and record your info on your notes.
FERNS
Ferns are Vascular Plants
Ferns are vascular plants.
The tube-like tissues of the vascular system moves water through a plant’s body more quickly than when water moves cell by cell. The tube are called xylem and phloem. Because of this, vascular plants can grow much larger than nonvascular plants. Vascular tissue also provides support for the weight of a larger plant. The leaves of a fern are called fronds. On the backside of a fern frond there are many small clusters. The clusters are full of spores. Label the frond and spore clusters on your drawing above. |
Ferns live in a wide range of habitats. They are both terrestrial and aquatic. Newly forming fronds are called fiddleheads. Wind spreads the spores.
Fern Benefits
- Help prevent erosion
- fiddleheads are eaten as food
- ornamental plants for yards and homes
- helped form coal deposits millions of years ago.