Classifying Plant Groups4.1

OrganizationPlants

Vascular Nonvascular

Mosses and related plants

SeedSeedless

Ferns and related plants

Angiosperms Gymnosperms

Learning Targets I can understand plants are classified

according to similar structures I can explain the difference between

vascular and nonvascular plants I can compare and contrast seed plants

and seedless plants I can define angiosperm, gymnosperm,

dicot and monocot

How are plants Classified? Scientists have discovered over 300,000

different kinds of plants

About 1,000,000 plants may exist that have not been found and named

Scientists believe these plants live in the tropical rain forest

Classification Plants are classified according to

whether they have body parts such as seeds, tubes, roots, stems, and leaves

There are 3 main groups of plants: Seed Plants Ferns Mosses

History of Classification The Greek philosopher Aristotle first

classified plants and animals

Carl Linnaeus then developed a classification system still in use today

All living things have a scientific name which consists of the genus and species

Vascular Plants Vascular means “vessel” or “tube”

Vascular plants have tube-like cells

Seed plants and ferns are examples of vascular plants

Vascular (cont.) These tube-like cells form tissue called

vascular tissue

The tissue forms tubes that transport food and water through the plant

Vascular plants have well-developed leave, stems, and roots

Vascular Tissue This tissue is important in two ways:

First, it allows food and water to be transported over a distance Plants can grow where water is not always

present

Second, vascular tissue is thick and provides support for the plant This allows the plant to grow taller

Nonvascular Plants Nonvascular plants do not have tube-

like cells These plants are short and must have

constant contact with water They do not have tubes to transport

water or support them They do not have true leaves, stems, or

roots Mosses are nonvascular plants

Vocabulary Vascular Plant Nonvascular Plant

Self Check Questions, pg. 69 #1-5 COMPLETE SENTENCES

What are Seed Plants?4.2

What are Seed Plants? Seed plants use seeds to reproduce

A seed is a plant part that contains a beginning plant and stored food

The beginning plant part is called an embryo

Seeds have a seed coat, which holds in moisture

Seed Plants (cont.) When conditions are right, the embryo

grows into a full-sized plant

Seed plants are the largest group of plants

They are divided into 2 sub groups: flowering and nonflowering plants

Angiosperms (Flowering) Most species of plants are angiosperms A capsule, or fruit, protects the seeds of

angiosperms The fruit forms from part of the flower Angiosperms are divided into two

groups: Dicots Monocots

Dicots Have 2 seed leaves (on the embryo)

Crisscross pattern of veins on leaves

Most flowering plants are dicots

Examples: fruits, vegetables, rose, sunflower

Monocots Have only one seed leaf

Parallel pattern of veins on leaves

Mostly grasses, but some flowers

Examples: grass, corn, wheat, rice, lily, orchid

Gymnosperms (Nonflowering) Do not produce flowers

Seeds are not surrounded by a fruit

Seeds are produced inside cones

Example: seeds of pine trees form on the scales of cones

Conifers The major group of gymnosperms

Cone-bearing plants

Woody shrubs or trees

Main source of paper and wood products

Examples: pine, spruce, fir

Conifers (cont.) Most have green leaves all year long They are called evergreens Leaves are shaped like needles Makes it easier to live in dry places and

store water Grow in places where other plants

cannot grow (shallow, rocky soil and along coast)

Vocabulary Angiosperm Gymnosperm Embryo Conifer Seed Monocot Dicot

Self Check Questions, pg. 73 #1-5 COMPLETE SENTENCES

What are Seedless Plants? 4.3

Ferns (Vascular) Largest group of seedless plants Well-developed leaves, stem, and roots Mostly tropical plants Leaves are called fronds (large and flat) Fronds uncurl as they grow Sori are clusters of reproductive

cells(spores)found on the underside of fronds

Spores Spores are the reproductive cells of

ferns and mosses After they are released, spores must

land in a moist place or they will dry out

Spores that drop in a moist place will have produce a tiny plant

The plant must have constant moisture to grow

Spores vs. Seeds Spores must have moist landing and

constant water source

Seeds have a seed coat to constantly deliver food and water

Seeds can survive longer than spores in dry conditions, which is why there are more seed plants in the world

Mosses (Non-Vascular) Reproduce by spores Simple leaf-like and stem-like parts No vascular tissue to transport water

and food, so they must live in moist, shady area (wet soil)

Have root-like threads called rhizoids Mosses look like little trees and often

form carpet-like mats on the forest floor

Vocabulary Frond Sori Spore Rhizoid

Self Check questions pg. 78 COMPLETE SENTENCES