Chapter 21-24WHAT ARE PLANTS

&

HOW ARE THEY CLASSIFIED

• List the characteristics of plants.

• Identify some of the plant kingdom divisions.

• Compare and contrast characteristics of the different groups of plants.

Section Objectives:

BOTANY

The study of plants

• Multicellular eukaryotes

• Autotrophic: produce their own food (glucose) through the process of photosynthesis and store food in the form of starch.

• Plant cells have thick cell walls made of cellulose.

• The stems and leaves of plants have a waxy waterproof coating called a cuticle.

• Contain chloroplast that contain pigment chlorophyll

Plant CharacteristicsPlant Characteristics

Plant Characteristics Cont.

There are three main organs in a plant1. Roots: Functions; A. absorb water and

nutrients from soilB. anchor plants into the ground

C. hold plant upright and prevent being knocked over by wind or rain

Organs in a Plant Cont.

2. Stems: Functions;A. holds leaves up to the sun; all plants compete

for sun

3. Leaves: Functions;A. They are broad to capture more sunlight

B. They have a waxy coat (cuticle) to hold in H2O

C. They have pores to allow CO2 to enter and O2 to exit

Other Parts and Processes of Seed Plants:

4. Pollen Grain – male gamete of seed plants is contained in this structure

5. Pollination – the carrying of pollen from male to female by wind, insects,

birds and small animals

Other Parts and Processes of Seed Plants Cont:

6. Seeds: structures that protect the zygotes of plants

7. Embryo – tiny plant after fertilization

8. Seed Coat: protects the seed from drying out, this allows survival in a variety of

climates

Plant Kingdom BreakdownNonvascular (mosses & liverworts)

• Plant Seedless Spore

Bearing (ferns)

Vascular Plant Conifers

(gymnosperm)Seed Bearing

Flowering

(angiosperms)

Monocot Dicot

Phylogeny of PlantsPhylogeny of Plants• 1st division: do they have vascular tissue:

vascular or nonvascular.

• 2nd division: does it produces seeds: non-seed plants and seed plants.

• 3rd division: is seed bearing plants a cone bearing or flower bearing: gymnosperms or angiosperms.

• 4th division: angiosperms are divided: monocots and dicots.

• No vascular tissue

• Limited to moist habitats by streams and rivers or in temperate and tropical rain forests.

• Small in size and shape

• Mosses

What is a nonvascular plant?What is a nonvascular plant?

• Bryophytes, the mosses, are nonvascular plants that rely on osmosis and diffusion to transport materials.

• Moss plants are usually low to the ground and have leaflike structures

• Simplest form of plants

• Found in moist areas that are shaded

• Reproduce by spores

Phylum Bryophyta: nonvascular plantsPhylum Bryophyta: nonvascular plants

Difference between vascular & nonvascular plants

Difference between vascular & nonvascular plants

•Vascular plants can live farther away from water than nonvascular plants.

•Vascular plants can grow much larger than nonvascular

plants.

Vascular PlantsVascular Plants•Contain vascular tissue which is xylem and phloem in the stem of the plants

•Xylem transports water and dissolved substances from the roots to other parts of plant

•Phloem transports dissolved sugar from leaves (photosynthesis) to the rest of plant

Phylum Tracheophytes• All vascular plants (have xylem and

phloem)• Can live in drier climates than

nonvascular• Uses roots to absorb food and minerals

and uses vascular tissue to transport it

SEEDLESS VASCULAR PLANTSSEEDLESS VASCULAR PLANTS

• Ferns are the most well-known and diverse group of non-seed vascular plants.

• They have leaves called fronds.

• Reproduce by spores on their leaves.

• Need water to reproduce so they are found in moist areas.

SEED BEARING VASCULAR PLANTSSEED BEARING VASCULAR PLANTS

• Seed plants produce seeds

• A seed consists of an embryonic plant and a food supply covered by a hard protective seed coat.

• All seed plants have vascular tissues.

• These tend to adapt well to their environment

2 Divisions of Seed Bearing

1. Gymnosperms/Conifers

2. Angiosperms/Flowering Plants

Gymnosperms

• Gymnosperms seeds sits on the scales

• Scales – special leaves that contain male and female reproductive structures

• Cones – scales that are grouped into larger structures, there are male and female cones

Cones Cont.• A. Male cones produce gametophytes called

pollen (starts out closed and when opened it releases pollen)

• Female cones produce gametophytes called eggs (starts out closed and when opened it releases seeds, much bigger than male cones)

• Female cone holds the seeds that develop

3 Classes Gymnosperms

• 1. Cyads

• 2. Ginkgoes

• 3. Conifers

Cycads

• Palmlike plants present with the dinosaurs in the Triassic Period

• They grow naturally in Mexico, West Indes, Florida, Parts of Asia, Africa, and Australia

Ginkgoes• Were alive during the dinosaur period.

• There is only 1 living species (Ginko biloba)

• The oldest living seed plant

Conifers• Commonly called evergreens, the most

abundant gymnosperm on Earth

• Examples: pines, spruce, fir, cedar, sequoias, and redwoods

• Leaves are long and thin and are called needles

Conifers/GymnospermsConifers/Gymnosperms• Cone-bearing trees such as pine, fir,

cypress, and redwood.

• Cones are scaly structures that support male or female reproductive structures.

• Their leaves that are needlelike or scaly.

• The reproductive structures of most conifers are produced in cones.

• Most have male and female cones on different branches of the same tree.

• The male cones produce pollen, female cones are much larger and stay on the tree until the seeds have matured.

Reproduction in the Conifers

Evergreen vs. Deciduous trees

• Most conifers are evergreen —plants that retain some of their leaves for more than one year.

• Deciduous plants drop all their leaves each fall or when water is scarce or unavailable. It reduces water loss. A tree with no leaves cannot photosynthesize & must remain dormant during this time.

AngiospermsAngiosperms• Commonly called the flowering plants, are the

largest, most diverse group of seed plants living on Earth.

• They produce flowers from which fruits develop.

• A fruit usually contains one or more seeds. Ex: apples, oranges, beans, peas, pumpkins, tomatoes, eggplants

• 2 classes: monocotyledons (monocots) & dicotyledons (dicots)

Monocots

• Examples: corn, wheat, lilies, daffodils, orchids; monocots have only 1 seed leaf

Dicots

• Examples: roses, clover, oaks, tomatoe, daisies; dicots have 2 seed leaves

Monocot and Dicot Characteristics

• Monocot:

1.Veins are parallel

2.Flowers, petals and parts in 3’s or multiples of 3 (3,6,9,12)

• Dicots

1.Veins form branching network

2.Flowers, petals, and parts occur in 4’s or 5’s or multiples (4,8,12 or 5,10,15)

Adaptations in Angiosperms• Angiosperms have roots, stems, and

leaves.

• They produce flowers and form seeds enclosed in a fruit.

• A fruit develops from a flower’s female reproductive structure(s).

MONOCOTS• One cotyledon (seed leaf)

• Parallel venation in the leaves

• Fibrous root system

• Flower parts in multiples of 3

• Vascular tissue is arranged in a scattered bundle

DICOTS• Two cotyledons (seed leaf)• Net venation in the leaves• Taproot root system• Flower parts in multiples of either 4 or 5• Vascular tissue is arranged in a circular ring

Other Info.

• Vector Pollination – pollination by animals

• The bitter taste of unripe fruit is to protect fruit from being eaten by animals until ripe when seeds can be spread

• Green fruit is a protective mechanism to hide fruit until its ripe

Moncots and dicotsDistinguishing Characteristics of Monocots and Dicots

Seed Leaves LeavesVascular Bundles in Stems

Flower Parts

Monocots

Dicots

One cotyledon Usually parallel Scattered Multiples of three

Two cotyledons

Usually netlike Arranged in ring Multiples of four and five

• Describe the alternation of generations in land plants.

• Describe sexual reproduction in angiosperms

Section Objectives:

• An alternation of generations consists of a sporophyte stage and a gametophyte stage.

• Sporophyte stage is the 2n stage and it is asexual reproduction through mitosis

• Gametophyte stage is n stage and is sexual division through meiosis.

Alternation of GenerationsAlternation of Generations

What is a flower?What is a flower?

• The process of sexual reproduction in flowering plants takes place in a flower, which is a complex structure made up of several organs.

FEMALE Structure of the Flower

• Pistil: the female organ of the flower– Ovary: at bottom of the pistil which

produced the ovule– Stigma: located at the top of the

pistil & is where pollen grains attach to (sticky stigma)

– Style: long tube of the pistil & is where pollen grains travel down until they reach the ovule

– Ovule: develops into a seed; within the ovary

MALE Structure of the Flower

• Stamen: the male structure of the flower (contains word men)– Anther: located at top of the stamen &

produced pollen– Filament: thin, stem like portion a stamen

Pollination

• Process of transferring ripe, pollen from anther to stigma

• Self pollination: pollen on 1 plant is transferred to the stigma on the same flower

• Cross pollination: pollen on 1 flower is transferred to the stigma of another flower

Structures of Flowering Plants• Roots: Anchor plants, absorb

water & minerals and store food• Stems: Support for leaves,

reproductive parts, & transportation part of plant

• Leaves: The factories for the plants; Take energy from sun and make sugar

• Vascular Tissue: transportation system of the plant

Types of Stems•Herbaceous plants: flexible stems

and includes most of the annuals•Woody plants: stems rigid & hard

and includes most of plants that live from season to season

TRANSPIRATION

–Process where plants lose water through their leaves

Non Vascular

Plants

Seedless Vascular Plants

Gymnosperms vascular plants

Angiosperm vascular plant

Example Mosses Ferns Pine Tree Fruit treeVascular Tissue

No Yes Yes Yes

True roots, stems, & leaves

No Yes Yes Yes

Flowers No No No YesReproduce Spores Spores Seeds Seeds

Seeds no no Yes, in cones Yes, in flowers