Vascular Seed Plants Gymnosperms and Angiosperms Seed Plants

Vascular, Seed Plants Gymnosperms and Angiosperms

Seed Plants • Do not require water for reproduction because of pollination, so can live almost anywhere • Seed – protective part of plant that contains a plant embryo (baby) and stored food • Most plants are seed plants

Gymnosperms • Most have their seeds in cones --- conifers (“conebearing”) • Most keep their leaves all year (evergreens)

Coniferophyta—Conifers • Cone—cluster of sporophylls • Examples: pine, firs, spruces, junipers, cedars • Most evergreen, leaves needle-like Methuselah—bristlecone pine… 4600+ yrs. old!

Conifers General Sherman (left)…CA Mtns…trunk circumference is 26 m! Redwoods…tip of northern CA…can grow to 110 m+ tall! (right)

Conifers…. . • Roots and stems are hard and woody. • Wood is a plant material made mostly of xylem. • Conifers are a source of wood, cardboard, turpentine, disinfectants and fuel. • They provide food and shelter to many animals.

Life Cycle of a Gymnosperm

Life Cycle of a Pine Tree Produce male and female cones Male cones produce pollen (sperm) Wind carries pollen to larger female cones The sperm cells fertilize the eggs in the female cones. • Seeds, containing the embryo, form between the woody scales of the cone • •

Anthophyta—Angiosperms flowering plants 250, 000 species

Food supply

Angiosperms… • Produce seeds inside a flower • Flowers have male (produce pollen)and female parts (produce eggs) • Pollen is carried to the egg by wind, insects, or other animals. • 2 classes: monocots and dicots

Monocots • One seed leaf—cotyledons • Examples: lilies, orchids, grasses, grain crops

Dicots • 2 cotyledons • Examples: roses, peas, sunflowers, oaks, maples

Dicot vs. Monocot Roots Have one main long Dicots root (taproot) and branch roots. Tap Root System Have all roots about the same length and none very long. Fibrous Root System Monocots

• Dicot leaves have branching (net-like) veins • Monocot leaves have parallel veins Leaves

Flowers

Stems Vascular tissue organized in a ring Vascular tissue scattered in stem

Roots Dicot Root Vascular tissues Monocot Root

Deciduous Trees that lose their leaves in the Fall.

Evergreens never lose their leaves. Most are conifers.

• Annuals— 1 year • Biennials— 2 years • Perennials—many years

Typical Flower

Parts of a Flower • Stamens: The male part, composed of filament and anther. Releases pollen. • Pistil: The female part, composed of style, stigma, and ovule. • Petals: The colorful parts. • Sepals: Leaf-like parts around petals.

Anatomy of a Flower

Another typical flower

Transpiration is the loss of water from the stomata --like plant sweat. Water enters through the roots. As water is lost from the stomata, water is draw up the step by capillary action and the cohesion of water molecules caused by hydrogen bonding moves the water up the stem.

Plant stems growing toward the light source and leaves facing the light. Is a. Phototropism plant response directed toward light All sunflowers facing the same way

hormone

Gravitropism in stems Is a plant response directed toward gravity Gravitropism in roots