Plant KingdomPlant Kingdom

Biology 112Biology 112

Kingdom PlantaeKingdom Plantae

The term plant is used to include organisms The term plant is used to include organisms that share the following characteristics:that share the following characteristics:

1.1. Ability to synthesize carbohydrates by Ability to synthesize carbohydrates by photosynthesisphotosynthesis

2.2. Presence of cellulose cell wallsPresence of cellulose cell walls

3.3. Alternation of generations in their life cyclesAlternation of generations in their life cycles

4.4. Lack of mobilityLack of mobility

•The gametophyte generation begins with a spore produced by meiosis. The spore is haploid, and all the cells derived from it (by mitosis) are also haploid. In due course, this multicellular structure produces gametes — by mitosis — and sexual reproduction then produces the diploid sporophyte generation.

Plant DiversityPlant Diversity

As environments change so do speciesAs environments change so do species Land plants have adapted with the evolution of Land plants have adapted with the evolution of

structures and systems for the transport of structures and systems for the transport of water; roots, stems and leaves; and a method water; roots, stems and leaves; and a method of reproduction that did not depend on water of reproduction that did not depend on water for the dispersal of gametesfor the dispersal of gametes

As plants became more complex they depend As plants became more complex they depend on water less for reproductionon water less for reproduction

ClassificationClassification

Scientists have devised a number of Scientists have devised a number of classification schemes for plants. The 3 classification schemes for plants. The 3 main groups we will look at are:main groups we will look at are:

1.1. AQUATICAQUATIC

2.2. NONVASCULARNONVASCULAR

3.3. VASCULARVASCULAR

Aquatic PlantsAquatic Plants

The simplest of plants live surrounded by The simplest of plants live surrounded by water b/c it satisfies their needs: nutrients, water b/c it satisfies their needs: nutrients, moisture, spore dispersal.moisture, spore dispersal.

Most are green, brown and red algaeMost are green, brown and red algae Most are multicellularMost are multicellular The multicelled body is called a thallus and The multicelled body is called a thallus and

lacks conductive tissue as well as true roots, lacks conductive tissue as well as true roots, stems, and leaves.stems, and leaves.

Adaptations for a Terrestrial Adaptations for a Terrestrial LifestyleLifestyle

Mosses, liverworts, and ferns, gave rise to Mosses, liverworts, and ferns, gave rise to more complex terrestrial plants that bear seeds more complex terrestrial plants that bear seeds and flowering plants. and flowering plants.

The two lineages are divided into vascular and The two lineages are divided into vascular and nonvascular plantsnonvascular plants

Vascular tissue is conducting tissue called the Vascular tissue is conducting tissue called the xylem and phloem. These allow for transport xylem and phloem. These allow for transport of water and nutrients throughout the plant.of water and nutrients throughout the plant.

Vascular and Non VascularVascular and Non Vascular

Both vascular and nonvascular plants have a Both vascular and nonvascular plants have a waxy protective cuticle, numerous stomata and waxy protective cuticle, numerous stomata and complex reproductive structures. complex reproductive structures.

The cuticle is a non cell layer secreted by the The cuticle is a non cell layer secreted by the epidermal cells which keep the plant from epidermal cells which keep the plant from drying out.drying out.

Stomata are pores in the epidermis of plants, Stomata are pores in the epidermis of plants, usually in leaves. Allow for exchange of gases. usually in leaves. Allow for exchange of gases.

Nuclei

Guard Cells

STOMATA

Chloroplasts

NONVASCULAR “LAND” PlantsNONVASCULAR “LAND” Plants

Also called bryophytesAlso called bryophytes Confined to moist habitats b/c they need water Confined to moist habitats b/c they need water

for sexual reproductionfor sexual reproduction Commonly found in wetlands, rain forests, and Commonly found in wetlands, rain forests, and

roadside ditchesroadside ditches Generally less than 20cm tallGenerally less than 20cm tall 3 classes: mosses, liverworts, and hornworts3 classes: mosses, liverworts, and hornworts

BryophytesBryophytes

Have leaflike, stemlike and rootlike organsHave leaflike, stemlike and rootlike organs Have rhizoids (root-like filiments) that anchor the Have rhizoids (root-like filiments) that anchor the

plantplant Water and nutrients move from cell to cell by Water and nutrients move from cell to cell by

diffusiondiffusion Mosses are the most common and they hold a lot of Mosses are the most common and they hold a lot of

water – this sponge like feature makes them useful in water – this sponge like feature makes them useful in oil spills, and potting soilsoil spills, and potting soils

Ex: used sphagnum (moss) as a maxipad long agoEx: used sphagnum (moss) as a maxipad long ago

Vascular PlantsVascular Plants

Division Tracheophyta which includes the Division Tracheophyta which includes the “true” terrestrial plants such as the familiar “true” terrestrial plants such as the familiar ferns, shrubs, trees, and flowering plantsferns, shrubs, trees, and flowering plants

They transport nutrients, water and minerals They transport nutrients, water and minerals via a vascular systemvia a vascular system

With the exception of ferns, vascular plants With the exception of ferns, vascular plants have evolved reproductive structures that are have evolved reproductive structures that are free of total dependence on waterfree of total dependence on water

Vascular StructureVascular Structure

The vascular tissue provides a continuous The vascular tissue provides a continuous internal conduction system between roots, internal conduction system between roots, stems and leaves. stems and leaves.

It also provides structural supportIt also provides structural support

Two Types of Vascular PlantsTwo Types of Vascular Plants

1.1. Those that produce seedsThose that produce seeds

2.2. Those that do not produce seedsThose that do not produce seeds

Seedless PlantsSeedless Plants

Dominant land plant 300 million years agoDominant land plant 300 million years ago Most are now extinctMost are now extinct

Seed PlantsSeed Plants

Reproductive Adaptations and an improved Reproductive Adaptations and an improved vascular system largely account for the success vascular system largely account for the success of seed plantsof seed plants

The most widely distributed and complex The most widely distributed and complex group of plants on Earthgroup of plants on Earth

270 000 known seed plants270 000 known seed plants Have separate male and female gametophytes, Have separate male and female gametophytes,

as well as roots, stems and leaves.as well as roots, stems and leaves.

Seed PlantsSeed Plants Seed typeSeed type is the main criterion for distinguishing the is the main criterion for distinguishing the

two major seed-bearing groups; gymnosperms and two major seed-bearing groups; gymnosperms and angiospermsangiosperms

Greek: sperma “seed”, gymnos “naked”, and angeion Greek: sperma “seed”, gymnos “naked”, and angeion “vessel”“vessel”

Gymnosperms produce unprotected or “naked” seeds Gymnosperms produce unprotected or “naked” seeds in conelike structures, and in conelike structures, and

Angiosperms produce seeds that are enclosed and Angiosperms produce seeds that are enclosed and protected inside the fruit, which is formed by the protected inside the fruit, which is formed by the flower. flower.

Seeds ensure the survival of seed plants by resisting Seeds ensure the survival of seed plants by resisting desiccation.desiccation.

ANGIOSPERMS ANGIOSPERMS (Flowering Plants)(Flowering Plants)

Characteristics of AngiospermsCharacteristics of Angiosperms

There are thousands of different kinds of flowering There are thousands of different kinds of flowering plantsplants

They range from tiny pond-surface plants, which are They range from tiny pond-surface plants, which are less than 1mm long to trees 100m tall.less than 1mm long to trees 100m tall.

Angiosperms ALL produce seeds in reproductive Angiosperms ALL produce seeds in reproductive structures called flowers. Then, as the seeds mature, structures called flowers. Then, as the seeds mature, the flower changes into a fruit.the flower changes into a fruit.

The name angiosperm means “covered seed”The name angiosperm means “covered seed” Mature seeds are scattered, or dispersed, along with Mature seeds are scattered, or dispersed, along with

the fruitthe fruit

Monocots and DicotsMonocots and Dicots

Botanists are able to divide the 235,000 species of Botanists are able to divide the 235,000 species of angiosperms into two large groups based on the angiosperms into two large groups based on the structure of their seedsstructure of their seeds

Inside the seeds of angiosperms are tiny embryonic Inside the seeds of angiosperms are tiny embryonic leaves called leaves called cotyledonscotyledons. The seeds of one group of . The seeds of one group of angiosperms have one cotyledon, called angiosperms have one cotyledon, called monocotyledons or monocotyledons or monocotsmonocots. .

Other angiosperms have two cotyledons. These are Other angiosperms have two cotyledons. These are called dicotyledons or called dicotyledons or dicotsdicots

Monocots and DicotsMonocots and Dicots

They also have distinctive patterns of veins in They also have distinctive patterns of veins in their leaves. their leaves.

The veins of monocot leaves are parallel to The veins of monocot leaves are parallel to each othereach other

The leaves of dicots usually have netlike veinsThe leaves of dicots usually have netlike veins

Monocot ExamplesMonocot Examples

Tulips, daffodils, irises, lilies, palm treesTulips, daffodils, irises, lilies, palm trees

Dicot ExamplesDicot Examples

Buttercups, peas, roses, sunflowers, maple Buttercups, peas, roses, sunflowers, maple trees, and dandelionstrees, and dandelions

Grass?Grass?

The leaf blade of grasses indicates whether The leaf blade of grasses indicates whether they are monocots or dicots based on leaf they are monocots or dicots based on leaf veins.veins.

To which group do grasses belong?To which group do grasses belong?

You are right if you said monocots!You are right if you said monocots!

Page 453 of TextPage 453 of Text

Draw Figure 19.14 here!Draw Figure 19.14 here!

GYMNOSPERMSGYMNOSPERMS

GymnospermsGymnosperms

Represent all seed plants that DO NOT form Represent all seed plants that DO NOT form flowers (therefore do not have seeds enclosed flowers (therefore do not have seeds enclosed within a fruit)within a fruit)

The most numerous and widespread are the The most numerous and widespread are the conifers (cone bearing)conifers (cone bearing)

ConifersConifers

Cone bearing woody trees and shrubsCone bearing woody trees and shrubs Leaves are usually needlelikeLeaves are usually needlelike Most are evergreen (don’t drop their leaves in the Most are evergreen (don’t drop their leaves in the

Autumn)Autumn) Conifers DO shed their needles, just not all at once – Conifers DO shed their needles, just not all at once –

usually 2 to 4 yearsusually 2 to 4 years Grow in many different environmentsGrow in many different environments 600 species (pine, fir, spruce, cedar, hemlock, 600 species (pine, fir, spruce, cedar, hemlock,

sequoiassequoias Produce useful products, ie. lumber/paperProduce useful products, ie. lumber/paper

Typical Conifer Life CycleTypical Conifer Life Cycle

Copy Figure 19.10 into your notebookCopy Figure 19.10 into your notebook

Summary of Life CycleSummary of Life Cycle

Female cone is closed and sticky with resinFemale cone is closed and sticky with resin Pollen (from male) lands on the female conePollen (from male) lands on the female cone Meiosis begins and the embryo formsMeiosis begins and the embryo forms Once the seed is fully mature, the cone scales Once the seed is fully mature, the cone scales

open up and the seeds are dispersed via wind, open up and the seeds are dispersed via wind, animals, water, etc…..animals, water, etc…..

Plant Structure & DevelopmentPlant Structure & Development Like the human body, plants contain many different Like the human body, plants contain many different

types of cells, tissues, and organs.types of cells, tissues, and organs. Plants are structurally less complex than animals and Plants are structurally less complex than animals and

have fewer types of cellshave fewer types of cells A plant is composed of many repeating units (like an A plant is composed of many repeating units (like an

apartment)apartment) In seed plants, these units are organs such as leaves, In seed plants, these units are organs such as leaves,

roots, flowers and stems. Each organ acts as a roots, flowers and stems. Each organ acts as a separate unit.separate unit.

A plant may react to stress by varying the number of A plant may react to stress by varying the number of its partsits parts

Organs of Seed PlantsOrgans of Seed Plants

Seed plants have specialized organs for growth Seed plants have specialized organs for growth and reproductionand reproduction

Vegetative organs – roots, stems, and leaves, Vegetative organs – roots, stems, and leaves, function in the growth of the plant.function in the growth of the plant.

The reproductive organs of seed plants include The reproductive organs of seed plants include cones, flowers and fruitscones, flowers and fruits

ROOTSROOTS

Are organs that are specialized to collect water Are organs that are specialized to collect water and dissolved mineralsand dissolved minerals

Water is necessary for photosynthesis and Water is necessary for photosynthesis and metabolismmetabolism

Anchor the plant and store foodAnchor the plant and store food They may extend deep into the ground or far They may extend deep into the ground or far

from the plantfrom the plant

STEMSTEM

The parts of a plant above the soil surface The parts of a plant above the soil surface make up the make up the shoot system.shoot system.

A stem is an organ that conducts water and A stem is an organ that conducts water and minerals from the roots to the other parts of minerals from the roots to the other parts of the plantthe plant

Displays the leaves of the plant to the lightDisplays the leaves of the plant to the light The point on the stem where the leaf is The point on the stem where the leaf is

attached is called a attached is called a nodenode Store foodStore food

LEAVESLEAVES

Main food factories of seed plants. Main food factories of seed plants. Center of photosynthesisCenter of photosynthesis Somewhat flattened to allow maximum Somewhat flattened to allow maximum

collection of light energycollection of light energy They transport food to the stem to be used by They transport food to the stem to be used by

the rest of the plantthe rest of the plant Collectively the leaves are called the canopy.Collectively the leaves are called the canopy.

Plant TissuesPlant Tissues

Roots, stems, leaves, flowers and cones are all Roots, stems, leaves, flowers and cones are all composed of tissuescomposed of tissues

Each type of tissue consists of cells with Each type of tissue consists of cells with distinct structures and functions. Some tissues distinct structures and functions. Some tissues consist of dead cells, whereas other types are consist of dead cells, whereas other types are living and metabolizing.living and metabolizing.

Plant TissuePlant Tissue

All seed plants have common tissuesAll seed plants have common tissues: : meristematic tissue, epidermis, parenchyma, meristematic tissue, epidermis, parenchyma, supportive tissue, and vascular tissue.supportive tissue, and vascular tissue.

Meristematic TissueMeristematic Tissue Plants, unlike animals, continue to grow throughout Plants, unlike animals, continue to grow throughout

their lives. their lives. All plant growth originates in meristems.All plant growth originates in meristems. A meristem is a growing point of a plant consisting of A meristem is a growing point of a plant consisting of

unspecialized cells that are continually dividing and unspecialized cells that are continually dividing and producing new cells.producing new cells.

Meristems at the tip (or apex) of a root or stem are Meristems at the tip (or apex) of a root or stem are called apical meristems. These cause an increase in called apical meristems. These cause an increase in the length of a plant bodythe length of a plant body

Another kind of meristem, called the cambium, Another kind of meristem, called the cambium, causes a plant to grow in width.causes a plant to grow in width.

Meristematic TissueMeristematic Tissue

EpidermisEpidermis

A tissue that covers the entire plant bodyA tissue that covers the entire plant body Helps reduce water lossHelps reduce water loss Covered by a waxy cuticle (acts like a lip Covered by a waxy cuticle (acts like a lip

balm)balm) Do you think the epidermis of roots has a Do you think the epidermis of roots has a

waxy cuticle?waxy cuticle?

ParenchymaParenchyma

Tissue that is generally unspecializedTissue that is generally unspecialized Serves a variety of functionsServes a variety of functions Parenchyma cells store sugars and starchesParenchyma cells store sugars and starches When a plant is wounded, these cells begin to When a plant is wounded, these cells begin to

divide to heal the wounddivide to heal the wound In leaves, some types of parenchyma have In leaves, some types of parenchyma have

chloroplasts and carry on photosynthesis.chloroplasts and carry on photosynthesis.

Vascular TissueVascular Tissue

Supports the plantSupports the plant It conducts food, water and dissolved minerals from It conducts food, water and dissolved minerals from

one part of the plant to another.one part of the plant to another. Serves as the plants “plumbing system”Serves as the plants “plumbing system” Two types of vascular tissuesTwo types of vascular tissues::

1.1. PhloemPhloem – transports sugars and starches from one – transports sugars and starches from one part of a plant to anotherpart of a plant to another

2.2. XylemXylem – used for the transport of water and – used for the transport of water and dissolved mineralsdissolved minerals

Heath TextHeath Text

Continue on Chapter 23 (pg. 376)Continue on Chapter 23 (pg. 376) Chapter 24 (pg. 394)Chapter 24 (pg. 394)