WHAT IS A PLANT?

THREE CHARACTERISTICS OF PLANTS

• They are autotrophs.
• They have their own cell walls.
• They are also eukaryotes.

PLANT ADAPTATIONS FOR LAND

• Must have ways to obtain water.
• Must also obtain other nutrients from their surroundings.
• Transport materials in their bodies.
• Support their bodies.
• Reproduce.

NONVASCULAR PLANTS

• Nonvascular plants are plants that lack a well developed system of tubes for transporting water and other materials.
• Nonvascular plants are low growing.
• They cannot absorb water from the ground.
• They obtain water and other materials from their surroundings.
• Most nonvascular plants have only thin cell walls to provide support.

MOSSES

• Mosses have more than 10,000 species.
• Mosses are the most diverse group of nonvascular plants.
• The green fuzzy Moss is the gametophyte generation of the plant.
• Rootlike structures called rhizoids anchor the moss and absorb water and nutrients from the soil.
• The sporophyte generation from the gametophyte consists of a slender walk with a capsule at the end.

LIVERWORTS

• Liverworts have more than 8,000 species.
• Liverworts grow as a thick crust on rocks or soil.
• Wort is an old English word for "plant".
• Liverworts have saprophytes that are too small too see.

HORNWORTS

• There are fewer than 100 species of hornworts.
• Hornworts are found on rocks or tree trunks.
• Hornworts are named for the structures that grow out of gametophyte.
• Hornworts usually live in moist soil.
• The hornlike structures are the sporophytes.

SEEDLESS VASCULAR PLANTS

• Seedless vascular plants can grow tall.
• Their vascular tissue provides a way of transporting materials.
• Vascular tissue also provides vascular plants with strength and stability.
• Seedless vascular plants need to grow in moist surroundings.
• Seedless plants release spores into their surroundings.

FERNS

• There are more than 12,000 species of ferns.
• Ferns have true stems,roots, and leaves.
• The stems of most ferns are underground.
• The ferns fronds are divided into smaller parts that look like small leaves.
• Fern gametophytes are tiny plants that grow low to the ground.

HORSETAILS

• There are few species of horsetails on earth to this day.
• The stems of a horsetail are jointed.
• Horsetails grow in a circle around each joint.
• The stems contain silica.
• Americans used the plants to scrub their pots and pans back in colonial times.

CLUB MOSSES

• Club mosses have true stems, roots, and leaves.
• They also have the same life cycle as ferns.
• There are only a few hundred club mosses alive today.
• Club mosses have vascular tissue.
• Club mosses usually live in moist woodlands and near streams.

SEED PLANTS

• Seed plants outnumber seedless plants by more than 10 to 1.
• Seed plants share two important characteristics.
• They have vascular tissue and they use pollen and seeds to reproduce.
• All seed plants have body plans.

VASCULAR TISSUE : PHLOEM/XYLEM

• There are two types of vascular tissue.
• Phloem is the vascular tissue through which food moves.
• Xylem is Vascular tissue that water and minerals travel through.
• The roots absorb water and minerals from the soil.
• Theses materials enter the root's xylem and move upward into the stems and leaves.

POLLEN AND SEEDS

• Seed plants can live in a wide variety of environments.
• Seed plants produce pollen.
• Pollen is tiny structures that contain the cells that will later become sperm cells.
• After sperm cells fertilize the eggs, seeds develop.
• A seed is a structure that contains a young plant inside a protective covering.

SEED STRUCTURE

• A seed has three main parts - an embryo, stored food, and a seed coat.
• An embryo is a young plant that develops from the zygote.
• In all seeds, the embryo has one or more seed leaves, or cotyledons.
• The outer covering of a seed is called the seed coat.
• The seed coat acts like plastic wrap, protecting the embryo and it's food from drying out.

SEED DISPERSAL

• The scattering of seeds is called seed dispersal.
• Seeds are dispersed in many ways.
• One way seeds are dispersal is in new areas.
• Other seeds are enclosed in barblike structures.
• Another way seeds are dispersal is by water.

GERMINATION

• Germination occurs when the embryo begins to grow again and pushes out of the seed.
• Germination begins when the seed absorbs water from the environment.
• A seed that is dispersed far from its parent plant has a better chance of survival.
• When a seed does not have to compete with its parent for supplies it has a better chance of becoming a seedling.

ROOTS

• Roots anchor a plant in the ground.
• The more root area plant has, the more water and minerals it can absorb.
• They sometimes store food.

STEMS

• Stems can either be herbaceous or woody.
• Herbaceous stems contain no wood and are often soft.
• Woody stems are hard and rigid.
• Maple tress and roses have woody stems.

LEAVES

• Leaves capture the suns energy and carry out the food - making process of photosynthesis.
• The leaf's top and bottom surface layers protect the cells inside.
• Between the layers of cells are veins that contain xylem and phloem.
• The surface layers of the leaf have stomata.
• The pores of the stomata open and close to control when gases enter and leave the leaf.

GYMNOSPERM

• A gymnosperm is a seed plant that produces naked seeds.
• Every gymnosperm produces naked seeds.
• Many gymnosperms have needle - like or scale like leaves.
• Gymnosperms also have deep - growing root systems.
• Gymnosperms are the oldest type of seed plant.

EXAMPLES OF GYMNOSPERMS

• Cycads.
• Conifers.
• Ginkgoes.
• Gnetophytes.

ANGIOSPERM

• Angiosperms belongs to the group of seed plants.
• All angiosperms share two important traits.
• They produce flowers.
• They produce seeds that are enclosed in fruits.

EXAMPLES OF ANGIOSPERMS

• Arctic.
• Tropical jungles.
• Barren deserts.
• Ocean's edge.

MONOCOT VS. DICOT

• Monocots are angiosperms that have only one seed leaf.
• Dicots produce two seed leaves.
• Grasses,wheat, and rice are examples of monocots.
• Roses, and violets are examples of dicots.

PLANT TROPISMS: TOUCH, LIGHT, AND GRAVITY

• A plant's growth response toward or away from a stimulus is called a tropism.
• Bladderworts show a response touch to thigmotropism.
• All plants exhibit a response to light called phototropism.
• Plants also respond to gravity.