Plants

Kingdom PlantaeKingdom Plantae

Overview of Plant Diversity, Overview of Plant Diversity, Structure/Function, Reproduction, Structure/Function, Reproduction,

Responses and AdaptationsResponses and Adaptations

How many different kinds of plants can you How many different kinds of plants can you count on the following slide?count on the following slide? A. 10A. 10 B. 17B. 17 C. 34C. 34 D. Too many to count….D. Too many to count….

D. Too many to countD. Too many to count

Plants Make the World Go RoundPlants Make the World Go Round

Life as we know it today could not exist Life as we know it today could not exist without plants.without plants.Plants provide us with many essential items Plants provide us with many essential items other than food.other than food.

1.1. What are some items you use daily that What are some items you use daily that are are plant products? plant products?

2.2. What are three things plants need from What are three things plants need from animals, either directly or indirectly?animals, either directly or indirectly?

What is a Plant?What is a Plant?

Plants are members of the Kingdom Plantae.Plants are members of the Kingdom Plantae. All are multicellular eukaryotes.All are multicellular eukaryotes. All have cell walls made of cellulose.All have cell walls made of cellulose. Carry out photosynthesis using green pigments Carry out photosynthesis using green pigments

chlorophyll chlorophyll a a and and bb.. Most are autotrophic.Most are autotrophic.

A few are saprobic (decomposers) or parasitic.A few are saprobic (decomposers) or parasitic. Ex: Trees, shrubs, grasses, mosses, fernsEx: Trees, shrubs, grasses, mosses, ferns

What Plants Need to SurviveWhat Plants Need to Survive

Plants are sessile…they don’t move around. Plants are sessile…they don’t move around. This makes survival on land a difficult task.This makes survival on land a difficult task.

To be able to survive, they need:To be able to survive, they need: 1. Sunlight – they use energy from sunlight to 1. Sunlight – they use energy from sunlight to

carry out photosynthesis.carry out photosynthesis. 2. Water and Minerals – all cells require a constant 2. Water and Minerals – all cells require a constant

supply of water. As plants absorb water, they also supply of water. As plants absorb water, they also absorb minerals, which they need for growth.absorb minerals, which they need for growth.

What Plants Need to SurviveWhat Plants Need to Survive

3. Gas Exchange – plants require oxygen to 3. Gas Exchange – plants require oxygen to support cellular respiration as well as carbon support cellular respiration as well as carbon dioxide to carry out photosynthesis. dioxide to carry out photosynthesis.

4. Movement of Water and Nutrients – plants take 4. Movement of Water and Nutrients – plants take in water and minerals through their roots, but make in water and minerals through their roots, but make food in their leaves. They have to have specialized food in their leaves. They have to have specialized tissues to carry water upward and distribute tissues to carry water upward and distribute products of photosynthesis throughout the plant products of photosynthesis throughout the plant bodybody

Plant DiversityPlant Diversity

Cone-bearing plants760 species

Ferns & relatives11,000 species

Mosses & relatives15,600 species

Flowering plants235,000 species

Reproduction Free From WaterReproduction Free From Water

Seed plants do not require water for Seed plants do not require water for fertilization of gametes. fertilization of gametes. This allows plants to live anywhere.This allows plants to live anywhere.

Adaptations that allow this include:Adaptations that allow this include: Cones and Flowers Cones and Flowers

The gametophyte grows within the cone or flower.The gametophyte grows within the cone or flower. Cones = GymnospermsCones = Gymnosperms Flowers = AngiospermsFlowers = Angiosperms


PollenPollen The entire male gametophyte is contained in a tiny The entire male gametophyte is contained in a tiny

structure called a pollen grain.structure called a pollen grain. The grain is carried to the female reproductive The grain is carried to the female reproductive

structure by wind, insects, or small animals.structure by wind, insects, or small animals. This transfer or pollen is called pollination.This transfer or pollen is called pollination.


SeedsSeeds A seed is an embryo of a plant that is enclosed in a A seed is an embryo of a plant that is enclosed in a

protective covering that is surrounded by a food supply.protective covering that is surrounded by a food supply. An embryo is an organism in its early stage of An embryo is an organism in its early stage of

development.development. A seed coat surrounds and protects the embryo. A seed coat surrounds and protects the embryo.

This prevents drying out of the embryo.This prevents drying out of the embryo.

Seeds can be dispersed by wind, sticking to fur, or by Seeds can be dispersed by wind, sticking to fur, or by being eaten and dispersed by animals.being eaten and dispersed by animals.

Seed StructureSeed Structure

Seed Coat

Embryo

Stored Food Supply

Seed

Wing

Eat Your Seeds!Eat Your Seeds!

A seed contains both the embryo of a plant and A seed contains both the embryo of a plant and a food supply for that plant. If you have eaten a food supply for that plant. If you have eaten corn, you’ve eaten a seed. Do you like corn, you’ve eaten a seed. Do you like hamburger buns with sesame seeds on them? hamburger buns with sesame seeds on them? That’s another kind of seed you’ve eaten.That’s another kind of seed you’ve eaten.

After you answer the following questions, After you answer the following questions, exchange papers with a partner to see how exchange papers with a partner to see how many of the same seeds you listed.many of the same seeds you listed.

1. 1. In addition to sesame seeds, what are some other seeds In addition to sesame seeds, what are some other seeds that that are found in or on top of loaves of bread?are found in or on top of loaves of bread?

2. 2. In addition to corn, what are some other seeds that are In addition to corn, what are some other seeds that are eaten eaten as “vegetables”?as “vegetables”?

3.3. What are some seeds that you have eaten as snack foods?What are some seeds that you have eaten as snack foods?

4.4. What types of nutrients are found in seeds?What types of nutrients are found in seeds?

5.5. Do seeds have the same nutritional value for plants as Do seeds have the same nutritional value for plants as they they do for animals? Why?do for animals? Why?

Gymnosperms – Cone BearersGymnosperms – Cone Bearers

Gymnosperms are the most ancient surviving seed Gymnosperms are the most ancient surviving seed plantsplants

Conifers are the most common gymnosperms.Conifers are the most common gymnosperms. These include pines, spruces, firs, cedars, sequoias, These include pines, spruces, firs, cedars, sequoias,

redwoods, and junipers. redwoods, and junipers. Redwoods can grow more than 100 meters in height!Redwoods can grow more than 100 meters in height!

Needle-like leaves are characteristic of this group, Needle-like leaves are characteristic of this group, which is believed to have been evolved for dry, cool which is believed to have been evolved for dry, cool climates, and allows for water conservation.climates, and allows for water conservation.

Angiosperms – Flowering PlantsAngiosperms – Flowering Plants

Angiosperms develop Angiosperms develop unique reproductive unique reproductive organs known as organs known as flowers. flowers.

Advantage: attract Advantage: attract animals such as bees, animals such as bees, moths, or moths, or hummingbirds, which hummingbirds, which allows for efficient allows for efficient pollination.pollination. Helianthus annuus

Angiosperms – Flowering PlantsAngiosperms – Flowering Plants

Flowers contain ovaries, which surround and Flowers contain ovaries, which surround and protect the seeds.protect the seeds.

After pollination, the ovary develops into a After pollination, the ovary develops into a fruit.fruit.

A fruit is a wall of tissue surrounding a seed, A fruit is a wall of tissue surrounding a seed, which can be eaten by animals, and the seeds which can be eaten by animals, and the seeds are dispersed after they pass through the are dispersed after they pass through the animals digestive system.animals digestive system.

are categorized as

that completetheir life cycle in



Plants

Annuals Biennials Perennials

1 growingseason 2 years

More than2 years

Seed Plant StructureSeed Plant Structure

Three of the principle organs of seed plants are Three of the principle organs of seed plants are roots, stems and leaves.roots, stems and leaves.

1. Roots – the root system of a plant absorbs 1. Roots – the root system of a plant absorbs water and dissolved nutrients. water and dissolved nutrients. Roots anchor plants to the ground, preventing Roots anchor plants to the ground, preventing

erosion, and protects the plant from harmful soil erosion, and protects the plant from harmful soil bacteria and fungi.bacteria and fungi.

They also hold plants upright against wind and They also hold plants upright against wind and rain.rain.


2. Stems – a stem has a support system for the 2. Stems – a stem has a support system for the plant body, a transport system that carries plant body, a transport system that carries nutrients, and a defense system that protects nutrients, and a defense system that protects the plant against predators and disease.the plant against predators and disease. The stem must be strong enough to support The stem must be strong enough to support

branches and leaves.branches and leaves. The stem must also contain subsystems that lift The stem must also contain subsystems that lift

water and nutrients from the roots to the leaves.water and nutrients from the roots to the leaves.


3. Leaves – leaves are 3. Leaves – leaves are the plants main the plants main photosynthetic systems. photosynthetic systems. Leaves must contain Leaves must contain

subsystems that protect subsystems that protect against water loss and against water loss and conserve water, while conserve water, while allowing oxygen and allowing oxygen and carbon dioxide enter and carbon dioxide enter and exit the leaf.exit the leaf.

Stem

Root

Dermal Tissue

Vascular Tissue

Ground Tissue

Tissue SystemsTissue Systems

Plants consist of three main tissue systems: dermal Plants consist of three main tissue systems: dermal tissue, vascular tissue, and ground tissue.tissue, vascular tissue, and ground tissue.

1. Dermal Tissue – the outer covering of a plant 1. Dermal Tissue – the outer covering of a plant consists of a single layer of epidermal cells.consists of a single layer of epidermal cells. These outer cells are often covered with a thick These outer cells are often covered with a thick

waxy layer called the cuticle.waxy layer called the cuticle. Ex: Helps regulate water loss/gas exchange in Ex: Helps regulate water loss/gas exchange in

leaves, increases surface area in roots and aids in leaves, increases surface area in roots and aids in water absorption.water absorption.


2. Vascular Tissue – forms a transport system 2. Vascular Tissue – forms a transport system that moves water and nutrients throughout the that moves water and nutrients throughout the plant. It has two main components:plant. It has two main components: A. Xylem – tissue that carries water upward from A. Xylem – tissue that carries water upward from

the roots to every part of a plant.the roots to every part of a plant. B. Phloem – tissue responsible for the transport of B. Phloem – tissue responsible for the transport of

nutrients and the carbohydrates produced by nutrients and the carbohydrates produced by photosynthesis.photosynthesis.


3. Ground Tissue – the 3. Ground Tissue – the cells that lie between the cells that lie between the dermal and vascular dermal and vascular tissues make up the tissues make up the ground tissue. ground tissue. Photosynthesis occurs in Photosynthesis occurs in

the ground tissue of the ground tissue of plants. plants.

Leaf

Stem

Root

Dermal Tissue

Vascular Tissue

Ground Tissue

Types of RootsTypes of Roots

The two main types of The two main types of roots are taproots and roots are taproots and fibrous roots. fibrous roots. 1. Taproot – reach far 1. Taproot – reach far

underground for water.underground for water. Ex: Carrots, dandelions, Ex: Carrots, dandelions,

radishesradishes

2. Fibrous root – helps 2. Fibrous root – helps prevent erosion.prevent erosion.

Ex: GrassesEx: Grasses

Root FunctionsRoot Functions

Roots have 3 main jobs:Roots have 3 main jobs: 1. Uptake of Plant Nutrients - 1. Uptake of Plant Nutrients -

Role in Plant

Proper leaf growth and color; synthesis of amino acids, proteins, nucleic acids, and chlorophyll

Synthesis of DNA; development of roots, stems, flowers, and seeds

Synthesis of proteins and carbohydrates; development of roots, stems, and flowers; resistance to cold and disease

Synthesis of chlorophyll

Cell growth and division; cell wall structure; cellular transport; enzyme action

Result of Deficiency

Stunted plant growth; pale yellow leaves

Poor flowering; stunted growth

Weak stems and stunted roots; edges of leaves turn brown

Thin stems; mottled, pale leaves

Stunted growth; curled leaves

Nutrient

Nitrogen

Phosphorus

Potassium

Magnesium

Calcium


2. Active transport of minerals – by using 2. Active transport of minerals – by using active transport to accumulate ions from the active transport to accumulate ions from the soil, cells of the root epidermis create soil, cells of the root epidermis create conditions under which osmosis causes water conditions under which osmosis causes water to “follow” those ions and flow into the root.to “follow” those ions and flow into the root. The minerals then flow into the vascular tissue and The minerals then flow into the vascular tissue and

are dispersed throughout the plant.are dispersed throughout the plant.


3. Root Pressure – as minerals are pumped into 3. Root Pressure – as minerals are pumped into the vascular tissue, more and more water the vascular tissue, more and more water follows by osmosis.follows by osmosis. This produces a strong pressure that keeps forcing This produces a strong pressure that keeps forcing

water and nutrients in and up into the plant body, water and nutrients in and up into the plant body, and prevents the roots from filling up and and prevents the roots from filling up and expanding with water. expanding with water.

Without a constant root pressure, the stem and Without a constant root pressure, the stem and leaves would wither and die.leaves would wither and die.

Stem StudyStem Study

Imagine walking through a botanical garden. Imagine walking through a botanical garden. You probably would see many different kinds You probably would see many different kinds of plants, such as small and large trees, of plants, such as small and large trees, flowering plants, and cacti.flowering plants, and cacti.

1. How do the stems of trees, flowering plants, and cacti differ?

2. How are the stems of these plants similar?

Stem Structure and FunctionStem Structure and Function

Stems have three important functions: Stems have three important functions: They produce leaves, branches and flowers; they They produce leaves, branches and flowers; they

hold leaves up to the sunlight; and they transport hold leaves up to the sunlight; and they transport substances between roots and leaves.substances between roots and leaves.

Xylem and Phloem form continuous tubes Xylem and Phloem form continuous tubes from the roots through the stem to the leaves.from the roots through the stem to the leaves. The stem allows for the entire body of the plant to The stem allows for the entire body of the plant to

be connected, so water and nutrients can reach the be connected, so water and nutrients can reach the leaves.leaves.

The region where the The region where the leaf branches off of the leaf branches off of the stem is called a node.stem is called a node.

The spaces in between The spaces in between nodes are called nodes are called internodes.internodes.

In flowering plants, In flowering plants, buds form at the nodes buds form at the nodes in between the stem and in between the stem and the leaf.the leaf.

Node

Internode

Formation of WoodFormation of Wood

Most of what we call “wood” is actually layers Most of what we call “wood” is actually layers of xylem. These cells build up year after year, of xylem. These cells build up year after year, layer upon layer.layer upon layer.

Tree growth is usually seasonal – light colored Tree growth is usually seasonal – light colored wood rings are called “early wood,” dark wood rings are called “early wood,” dark colored layers wood rings are called “late colored layers wood rings are called “late wood.”wood.”

These names correspond with the times of year These names correspond with the times of year wood is formed, early and late in the year.wood is formed, early and late in the year.

Formation of BarkFormation of Bark

Bark includes all structures from the phloem to the Bark includes all structures from the phloem to the outside of the tree. outside of the tree.

As the phloem grows to accommodate the needs of As the phloem grows to accommodate the needs of the growing tree, it forces other vascular tissues the growing tree, it forces other vascular tissues outward.outward.

The expansion causes the oldest tissues to split and The expansion causes the oldest tissues to split and fragment at they are stretched by the expanding stem. fragment at they are stretched by the expanding stem.

By the time these layers reach the outermost area of By the time these layers reach the outermost area of the tree, they are usually dead and cracked and look the tree, they are usually dead and cracked and look like the bark we all have seen on trees.like the bark we all have seen on trees.

Layers of a Mature TreeLayers of a Mature TreeWood Bark

Xylem

Phloem

Meristem Tissue

Heartwood

Leaf ArrangementsLeaf Arrangements

Leaf StructureLeaf Structure

The structure of a leaf is The structure of a leaf is optimized for absorbing optimized for absorbing light and carrying out light and carrying out photosynthesis.photosynthesis.

The blade, the large The blade, the large flattened section, flattened section, collects sunlight.collects sunlight.

The stalked petiole The stalked petiole attaches the blade to the attaches the blade to the stem.stem.

Internal Structure of a LeafInternal Structure of a Leaf

Veins

Xylem

Phloem

Cuticle

Epidermis

Epidermis

Stoma

Spongymesophyll

Xylem

Epidermis

Stoma

Simple LeavesSimple Leaves

Compound LeavesCompound Leaves

Acacia cornigera

Leaf FunctionsLeaf Functions

There are three main functions of leaves.There are three main functions of leaves. 1. Leaves are specialized structures for 1. Leaves are specialized structures for

carrying out photosynthesis.carrying out photosynthesis. 2. Leaves lose water through stoma in a 2. Leaves lose water through stoma in a

process called transpiration. Lost water is process called transpiration. Lost water is replaced by water drawn in through the xylem.replaced by water drawn in through the xylem.

3. Leaves are the site of gas exchange. They 3. Leaves are the site of gas exchange. They take in carbon dioxide and give off oxygen take in carbon dioxide and give off oxygen during photosynthesis during photosynthesis

Water TransportWater Transport

Water transport occurs in a plant due to the following Water transport occurs in a plant due to the following processes:processes: 1. A constant root pressure makes water transport possible1. A constant root pressure makes water transport possible 2. Capillary action causes the water to rise upward in the 2. Capillary action causes the water to rise upward in the

phloem.phloem. 3. Water is pulled through the stoma in the leaves in a 3. Water is pulled through the stoma in the leaves in a

process called transpiration.process called transpiration. 4. Excess transpiration or low root pressure causes wilting, 4. Excess transpiration or low root pressure causes wilting,

in which the stoma would then close to slow transpiration in which the stoma would then close to slow transpiration and build root pressure back up.and build root pressure back up.

Evaporation of water molecules out of leaves.

Pull of water molecules upward from the roots.

Nutrient TransportNutrient Transport

We now know that transpiration We now know that transpiration pullspulls water upward water upward through a plant. But most plant nutrients, including through a plant. But most plant nutrients, including sugars, minerals, and organic molecules, are sugars, minerals, and organic molecules, are pushedpushed through the phloem.through the phloem.

Sugar movement flows from a source to a sink.Sugar movement flows from a source to a sink. The source can be any cell in which sugars are The source can be any cell in which sugars are

produced by photosynthesis.produced by photosynthesis. The sink is a cell where the sugars are used or stored.The sink is a cell where the sugars are used or stored. So….the sugars essentially move from where they are So….the sugars essentially move from where they are

produced to where they are stored. produced to where they are stored.

Flower StructureFlower Structure

Flowers are Flowers are reproductive organs reproductive organs that are composed of that are composed of four kinds of four kinds of specialized leaves: specialized leaves:

1. Sepals,1. Sepals, 2. Petals, 2. Petals, 3. Stamens, 3. Stamens, 4. Carpels.4. Carpels.

Stamen

FilamentAnther

CarpelStigma

Style

Ovary

Ovule SepalPetal

Flower VariationFlower Variation

Nelumbo lutea Oenothera speciosaCentaurea americana

Sabatia campestrisHelianthus annuus Danaus plexippus on

Cephalanthus occidentalis

Sepals and PetalsSepals and Petals

Sepals – the outermost circle of floral parts. Sepals – the outermost circle of floral parts. Usually resembling leaves, they enclose the bud Usually resembling leaves, they enclose the bud before it opens, and they protect the flower while before it opens, and they protect the flower while it develops.it develops.

Petals – the floral parts directly inside of the Petals – the floral parts directly inside of the sepals. They are often brightly colored to attract sepals. They are often brightly colored to attract insects and birds.insects and birds.

Because these two groups are non-reproductive Because these two groups are non-reproductive parts, they are sometimes called the sterile leaves.parts, they are sometimes called the sterile leaves.

Stamens and CarpelsStamens and Carpels

Stamens – made up of the male reproductive parts, the Stamens – made up of the male reproductive parts, the filament and anther. filament and anther. The filament is a long, thin stalk supporting the anther.The filament is a long, thin stalk supporting the anther. The anther is the site of meiosis, producing pollen.The anther is the site of meiosis, producing pollen.

Carpels – also called the pistil, made up of the female Carpels – also called the pistil, made up of the female reproductive parts.reproductive parts. The ovary is the site of meiosis, producing ovules.The ovary is the site of meiosis, producing ovules. The style is a narrow stalk, on which the stigma sits.The style is a narrow stalk, on which the stigma sits. The stigma is the sticky portion on top of the style, where The stigma is the sticky portion on top of the style, where

pollen grains land, and travel down the style to the ovary.pollen grains land, and travel down the style to the ovary.

Comparing Wind-pollinated and Animal-pollinated Plants

Characteristics

Pollination method

Relative efficiency of pollination method

Plant types

Reproductive organs

Adaptations that promote pollination

Characteristics

Pollination method

Relative efficiency of pollination method

Plant types

Reproductive organs

Adaptations that promote pollination

Wind-pollinatedPlants

Wind pollination

Less efficient

Mostly gymnosperms and some angiosperms

Cones

Pollination drop

Wind-pollinatedPlants

Wind pollination

Less efficient

Mostly gymnosperms and some angiosperms

Cones

Pollination drop

Animal-pollinated Plants

Vector pollination

More efficient

Angiosperms

Flowers

Bright colors, sweet nectar

Animal-pollinated Plants

Vector pollination

More efficient

Angiosperms

Flowers

Bright colors, sweet nectar

PollinationPollination

Most gymnosperms are wind pollinated, whereas Most gymnosperms are wind pollinated, whereas most angiosperms are pollinated by animals.most angiosperms are pollinated by animals. Ex: insects, birds, batsEx: insects, birds, bats

The work insect pollination would cost humans if we The work insect pollination would cost humans if we had to do it ourselves would cost billions of dollars a had to do it ourselves would cost billions of dollars a year.year.

Botanists suggest that insect pollination is the factor Botanists suggest that insect pollination is the factor largely responsible for the displacement of largely responsible for the displacement of gymnosperms by angiosperms during the last 100 gymnosperms by angiosperms during the last 100 million years.million years.

Seed DispersalSeed Dispersal

Dispersal by animals – seeds contained in Dispersal by animals – seeds contained in sweet, fleshy fruits are eaten by animals. sweet, fleshy fruits are eaten by animals. The tough coating of seeds protects them The tough coating of seeds protects them

from digestive enzymes.from digestive enzymes. The seed sprouts in the nutrient rich feces of The seed sprouts in the nutrient rich feces of

the animal, often in areas where there is less the animal, often in areas where there is less competition with the parent plants.competition with the parent plants.

Seed DispersalSeed Dispersal

Dispersal by wind and water – these seeds are Dispersal by wind and water – these seeds are typically lightweight, allowing them to be carried in typically lightweight, allowing them to be carried in the air or float on the surface of the water. the air or float on the surface of the water. Wind examples: Maple seeds twirl as they fall from tree; Wind examples: Maple seeds twirl as they fall from tree;

tumbleweeds break off at roots and tumble across the tumbleweeds break off at roots and tumble across the plains.plains.

Water examples: Coconuts are buoyant and allow seeds to Water examples: Coconuts are buoyant and allow seeds to float.float.

Water dispersal is one reason for the success of this species Water dispersal is one reason for the success of this species reaching remote islands.reaching remote islands.

Seed GerminationSeed Germination

Seed germination is the early growth stage of Seed germination is the early growth stage of the embryo.the embryo.

When seeds germinate, they absorb water, When seeds germinate, they absorb water, causing the seed tissues to swell, which cracks causing the seed tissues to swell, which cracks open the seed coat.open the seed coat.

The young root them emerges through the The young root them emerges through the crack and begins to grow, as the shoot grows crack and begins to grow, as the shoot grows in the opposite direction.in the opposite direction.

Different Types of Seeds Different Types of Seeds GerminatingGerminatingCorn Bean

Pea

Plant ResponsesPlant Responses

Tropism is the responses of plants to external Tropism is the responses of plants to external stimuli.stimuli.

There are three main plant tropisms:There are three main plant tropisms: 1. Gravitropism – the response of a plant to 1. Gravitropism – the response of a plant to

gravity. gravity. This causes the shoot of a germinating seed to grow out This causes the shoot of a germinating seed to grow out

of the soil – against gravity, and the root of the of the soil – against gravity, and the root of the germinating seed to grow down into the soil – with germinating seed to grow down into the soil – with gravity.gravity.

Plant ResponsesPlant Responses

2. Phototropism – the response of plants to light. 2. Phototropism – the response of plants to light. Causes the plant to grow toward a light source. This Causes the plant to grow toward a light source. This

response can be so quick that young seedlings reorient response can be so quick that young seedlings reorient themselves in a matter of hours.themselves in a matter of hours.

3. Thigmotropism – the response of plants to 3. Thigmotropism – the response of plants to touch.touch.

A plant that is touched often can become stunted in A plant that is touched often can become stunted in growth. growth.

Vines twist as they touch objects and twirl around them Vines twist as they touch objects and twirl around them to have something to anchor themselves to as they to have something to anchor themselves to as they continue to grow.continue to grow.

Phototropism ExamplePhototropism Example

Control Tip removed

OpaqueCap

Clear Cap

Opaque Sheath over

base

PhotoperiodismPhotoperiodism

Photoperiodism in Photoperiodism in plants is responsible for plants is responsible for the timing of seasonal the timing of seasonal activities such as activities such as flowering and growth.flowering and growth. Different types of plants Different types of plants

flower more when flower more when exposed to differing exposed to differing amounts of light and amounts of light and darkness. darkness.

Midnight

Noon

Long Day

Midnight

Noon

Short Day

Midnight

Noon

Interrupted Night

Short-Day Plant Long-Day Plant

Chrysanthemum Iris

Plant AdaptationsPlant Adaptations

Aquatic Plants – able to Aquatic Plants – able to tolerate mud that is tolerate mud that is saturated with water and saturated with water and nearly devoid of oxygen.nearly devoid of oxygen. Expansive roots allow Expansive roots allow

for maximum nutrient for maximum nutrient intake.intake.

Seed pods float when Seed pods float when mature and shoots grow mature and shoots grow very quickly after very quickly after germination to reach the germination to reach the water’s surfacewater’s surface

Nelumbo lutea

Plant AdaptationsPlant Adaptations Desert plants – plant Desert plants – plant

adaptations to a desert adaptations to a desert climate include extensive climate include extensive roots, reduced leaves, and roots, reduced leaves, and thick stems that can store thick stems that can store water.water. Roots reach far into soil to Roots reach far into soil to

reach water.reach water. Leaves sometimes modified Leaves sometimes modified

into spines to reduce water into spines to reduce water loss.loss.

Thick stems allow for Thick stems allow for maximum water conservation.maximum water conservation.

Nutritional SpecialistsNutritional Specialists Plants that have specialized Plants that have specialized

features for obtaining features for obtaining nutrients include carnivorous nutrients include carnivorous plants and parasites.plants and parasites. Carnivorous plants, such Carnivorous plants, such

at pitcher plants and at pitcher plants and Venus’ flytraps, trap Venus’ flytraps, trap insects and secret digestive insects and secret digestive enzymes that allow for enzymes that allow for absorption of the animal.absorption of the animal.

These plants usually live These plants usually live in bogs, or wet/acidic in bogs, or wet/acidic environments that allow environments that allow for little nutrients in the for little nutrients in the soil.soil.

Pitcher plant

Venus’ flytrap

Nutritional SpecialistsNutritional Specialists

Parasitic plants attach to Parasitic plants attach to a host plants and extract a host plants and extract water and nutrients water and nutrients directly from the host directly from the host plant.plant. Plants such as this attach Plants such as this attach

to their host plant and to their host plant and can eventually kill the can eventually kill the host as they leech all the host as they leech all the nutrients and water out nutrients and water out of the host.of the host.

Cuscuta gronovii

Nutritional SpecialistsNutritional Specialists

Epiphytes – plants that are Epiphytes – plants that are not rooted in the soil, but not rooted in the soil, but instead grow directly on the instead grow directly on the bodies of other plants – bodies of other plants – these are not parasitic.these are not parasitic. Most are found in the Most are found in the

rainforests.rainforests. They gather their own They gather their own

water and nutrients in their water and nutrients in their specialized bodies.specialized bodies.

Over half of all orchid Over half of all orchid species are epiphytes.species are epiphytes.

Plants

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Transcript of Plants