Standards: SC.912.L.14.7, SC.912.L.15.1, SC.912.L.18.12

Textbook: Chapter 22, 23 and 2.2

Overview of Plants

• · Relate the structures of plant tissues and organs to their roles in physiological processes. (ALD)

• · Explain how the structures of plant tissues and organs are directly related to their roles in physiological processes; roots, stems, leaves, flowers, fruits, and cones, meristematic, ground, dermal, and vascular tissues

• · Identify plant structures such as: cambium, guard cells, phloem, root hairs, root cap, seed, stomata, xylem, stamen, pistil, ovary, petals, sperm, egg, sepal, filament, anther, style, and stigma.

• · Describe the main tissues in mature root and stems.

• · Compare the structures and functions in different types of cells-plant, animal, prokaryotic, eukaryotic

• Summarize the properties of water and relate how these properties make water essential for life on Earth

Essential Content

A. Overview of Plant s (14.7)

1. Organs: Roots, Stems, Leaves, Flower

2. Tissues: Ground, Vascular, Dermal, Meristematic

3. Evolution of Plants: Mosses, Ferns, Gymnosperms, Angiosperms (15.1)

B. Physiological Processes of Plants (14.7)

1. Growth

a. Tissues: Meristematic Tissue

b. Structures: Root Cap, Cambium, Root Tip

2. Reproduction

a. Organs: Fruit, Cones, Flowers

b. Structures: Stamen (filament, anther), Pistil (stigma, style, ovary), Sepal, Petals, Sperm (pollen), Egg, Seed

3. Photosynthesis

a. Organelle: Chloroplast

b. Organs: Roots, Stems, Leaves

c. Tissues: Vascular Tissue

d. Structures: Root Hairs, Xylem, Stomata, Guard Cells,

4. Cellular Respiration (and its relationship to carbon)

a. Organelle: Mitochondria

b. Organs: Leaves, Stems, Roots

c. Tissues: Vascular Tissue

d. Structures: Phloem, Stomata, Guard Cells,

5. Transpiration (and its relationship to the water cycle)

a. Properties of water (18.12)

b. Organs: Roots, Stems, Leaves

c. Tissues: Vascular Tissue

C. Structures: Root Hairs, Xylem, Stomata, Guard Cells

Characteristics of Plants

Plants are eukaryotes that have cell walls containing cellulose. Mostly autotrophs, plants use chlorophyll a and b to carry out photosynthesis.

Without moving about, plants get what they need from the environment.

· Sunlight: gathered by leaves arranged in ways that maximize absorption

· Gas exchange: brings in oxygen and carbon dioxide and releases excess oxygen

· Water: absorbed mostly from the soil and transported internally

· Minerals: absorbed along with water from the soil

The History and Evolution of Plants

Ancestors of today’s land plants were water-dwellers similar to today’s green algae. Over time, the demands of life on land favored the evolution of plants more resistant to the drying rays of the sun, more capable of conserving water, and more capable of reproducing without water.

The first land plants were dependent on water and lacked leaves and roots.

Five major groups of plants are classified based on four important features:

· embryo formation

· specialized water-conducting tissues

· seeds

· flowers

Classifying Plants

Nonvascular: have no vessels, no roots, no stems or leaves.

Examples: Mosses & Liverworts

Vascular: have vessels to transport food and water. They have roots, stems and leaves.

Example: Grass, corn, trees, flowers, bushes

Xylem: transports water

Phloem: transports food & nutrients (Note how phloem starts with ph that sounds like the f in food!)

Gymnosperms

• "naked seeds"

• cone bearing plants (seeds grow on cones)

• needle like leaves

• usually stay green year round

• wind pollinated

• Examples: pine trees & evergreens

Angiosperms

• flowering plants

• seeds are enclosed in a fruit

• most are pollinated by birds & bees

• have finite growing seasons

• Examples: grasses, tulips, oaks, dandelions

• Divided into two main groups: Monocots & Dicots

Monocots

• Angiosperms have have 1 seed leaf (cotyledon)

• parallel veins on leaves

• 3 part symmetry for flowers

• fibrous roots

• Example: lilies, onions, corn, grasses, wheat

Dicots

• Angiosperms that have 2 seed leaves (cotyledons)

• net veins on leaves

• flowers have 4-5 parts

• taproots

• Examples: trees and ornamental flowers

Parts of the Plant

Roots

• water and minerals are absorbed (taproots vs fibrous roots)

• also used to anchor the plant

• movement of water up to leaves is influenced by TRANSPIRATION

Stems

• Support plant

• transport water through xylem

• transport nutrients through phloem

• a celery stalk soaked in food coloring will absorb the food coloring, you can see the xylem

• Two types of stems: herbaceous and woody

Leaves

• Photosynthetic organ of the plant, used to convert sunlight into food

• Stomata: pores within the leaf that open to let CO2 in and O2 out. Guard cells open and close.

• Cuticle: waxy covering on leaf that prevents water loss

Flower

• Reproductive organ of the plant

• Flowers are usually both male and female

• The male part of the flower is the STAMEN

• The female part of the flower is the PISTIL

• See your coloring sheet for more detail on flower anatomy

Plant Reproduction

• Pollen is produced by the stamen.

• Pollen moves away from the plant via the wind or other pollinators (birds & bees)

• The pollen lands on the pistil of another plant and fertilizes the eggs within the ovary

• The flower petals fall off, the ovary develops into a FRUIT that encloses the seeds

• Fruits are dispersed in a variety of ways (wind, animals)

• Fruits are not always edible, anything with a seed inside can be considered a fruit (helicopters, acorns, dandelions)

Asexual Reproduction in Plants

• Many plants can clone themselves, a process called VEGETATIVE PROPAGATION

• strawberry plants and other vine like plants send out runners, which grow into new plants

• some plant clippings will grow into new plants

• a Potato will grow into a new plant

How Plants Grow

• Germination occurs when a seed sprouts (usually caused by changes of temperature and moisture)

• Monocots have 1 seed leaf (cotyledon), Dicots have 2 seed leaves

• Perennials - live several years, and reproduce many times, woody plants are perennials

• Annuals - a plant that completes its life cycle in one growing season (grows, flowers, reproduces and then dies)

• Biennials - takes two growing seasons to complete, it reproduces in the second growing season

• Plants grow only at their tips in regions called MERISTEMS

• PRIMARY GROWTH makes a plant taller at roots and stems

• SECONDARY GROWTH makes a plant wider, or adds woody tissue

• Tree Rings tell the age of a tree, each ring represents a growing season. The photo shows a tree who has been through four growing seasons. The lighter thinner rings are winter periods.

• VASCULAR CAMBIUM: area of the tree that makes more xylem and phloem and forms the annual rings

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