Plant Structure & Function Mrs. Griffin. Photosynthesis Review Cross Section of Leaf.

Plant Structure & Function

Mrs. Griffin

Photosynthesis Review

• Cross Section of Leaf

Photosynthesis Review

• Equation?– 6H2O + 6CO2 ----------> C6H12O6+ 6O2

• What do plants give us?

• Site for gas exchange?– Stomata

Light

Introduction to Plants

• Multicellular or unicellular?

• Carry out photosynthesis using the green pigments chlorophyll a and b

• What do plants need to survive?– Sunlight, H2O & minerals, gas exchange

movement of water and nutrients

Early Plants

• The first plants evolved from organisms much like the green algae living today– Photosynthetic pigments– DNA sequence, close relationship– Fossils- similarities to today's mosses

Bryophytes

• Mosses & their relatives are generally called bryophytes, or NON-VASCULAR, plants.

• Depend on water for reproduction

• Why non-vascular?

• Draw water up by

osmosisMosses, liverworts, hornworts

Seedless Vascular Plants

• Fossil evidence shows ~420 million years ago moss-like plants were joined w/ other plants species

• These new plants were the 1st to have a transport system w/ vascular tissue

• What is the function of vascular tissue?– Transport water & nutrients

Vascular Tissue• Tracheids are the key

cells in xylem, the transport system that carries water upward from roots

• Phloem, second vascular tissue that transports nutrients and carbohydrates produced by photosynthesis.

• Transpiration?

Seed Plants

• Over 1 million years plants with the capability to form seeds became the most dominant group of photosynthetic organisms on land.

Seed Plants

• Gymnosperms bear their seeds directly on the surface of cones

• Angiosperms, “flowering plants,” bear their seeds w/in a layer of tissue that protects the seed

Angiosperms: Flowers & Fruits

• Angiosperms, “enclosed seed,” develop unique reproductive organs known as flowers

• Flowers contain ovaries, which surround and protect the seeds

• Fruit- a wall of tissue surrounding the seed

Flowering Parts

Stamen

Petal

Style

Stigma

Sepal

Pistil

FilamentOvary

Ovules

Anther

Pollen

Diversity of Angiosperms

• Incredibly diverse group….

• Categories provide a way of organizing diverse angiosperms

• Two classes w/in angiosperms: monocotyledons (monocots) & dicotyledonae (dicots)

• Names for the number of seed leaves, or cotyledons in the plant embryo.

Diversity of Angiosperms

• Monocots have one seed leaf, and dicots have two

• Cotyledon is the 1st leaf or 1st pair of leaves produced by the embryo of a seed plant

Characteristics of Monocots & Dicots