Ice Breaker

• What are the characteristics of algae?

• Prokaryote or Eukaryote?

• Autotroph or Heterotroph?

• Outside covered by a Cell Membrane or Cell Wall?

• What do you know about plants?

Chapter 8: Plants

Mrs. Charney

Northville Central School

Flowers of the Day

FoxgloveGerber Daisies

Section One: The Plant Kingdom• Plant- autotrophic, eukaryotes,

has many cells, undergo sexual reproduction, and surrounded by cell walls

• What makes them different from algae?• They are adapted to live on

land• Have ways to obtain and

keep water• Can transport materials

through their body

Adaptations for Living On Land

• Retaining Water- plants have a thick cuticle which is a waxy coating that helps to keep water in the plant

• Transporting Materials- plants have a system in which water, minerals, and food move throughout the body• Xylem- water goes up• Phloem- food goes

down

XylemPhloem

Adaptations for Living on Land

• Support- low-lying plants do not necessarily have this problem, but large plants and trees need to have rigid cell structures and vascular tissue (bark)

• Reproduction- plants undergo sexual reproduction that can be fertilized within a dry environment• Zygote- a fertilized cell

(sperm and egg are together)

Classifying Plants• Non-Vascular Plants-

plants that lack a good system for transporting materials up and down their bodies• Low-growing plants• Very slow method

• Vascular Plants- plants that have true vascular tissue (xylem and phloem)• Plants are taller• Quicker method

Do you think these trees would need

vascular tissue?

Partnered Ice Breaker

• What are two characteristics of plants that make them similar to algae?

• What is the difference between xylem and phloem?

• What is the difference between non-vascular plants and vascular plants?

Origin of Plants

• Fossil evidence shows that green algae are ancestors of plants today

Two Stages of Plant Life Cycles

• Sporophyte- produces spores

• Gametophyte- produces egg and sperm cells

Section Two: Plants Without Seeds

Pretty Flowers of the Day

Hydrangea

Black-Eyed Susan

Types of Seedless Nonvascular Plants

• Keep in mind that non-vascular plants do NOT have xylem and phloem

• Three groups of Nonvascular Plants• Mosses• Liverworts• Hornworts

• All three groups are low-growing and live in moist environments

• Sporophyte grows right out of gametophyte

Mosses• Most diverse group of

nonvascular plants (10,000 species)

• Rhizoid- thin, root-like structure anchor mosses and absorb water

• Spores produced in a capsule at the top

Liverworts• 8,000 species of liverworts

• Sporophyte named after the shape of the human liver

Hornworts

• Less than 100 species of hornworts

• Live among grass

• Sporophyte looks like a horn

Seedless Vascular Plants

• Have vascular tissue• Reproduce by spores

• Examples:• Ferns• Club Mosses• Horsetails

Ferns

• 12,000 species• Have true stems, roots,

and leaves• Major part of the fern is

the frond• Frond- leaves that

are divided into many smaller parts that look like small leaves

• Spores released from underside of leaves

Frond

Horsetails• Very few species left on Earth

• Very hard, bristly leaves

• Used by early Americans to clean their pots and pans

Club Mosses

• Only a few hundred species left on Earth

• Unlike true mosses, these mosses do have vascular tissue

• Looks like the small branch of a pine tree

Ice Breaker

• What is the difference between xylem and phloem?

• What is the difference between a plant that is non-vascular and a plant that is vascular?

Section 3: The Characteristics of Seed Plants

What are Seed Plants?• Seed plants are all around

you, and are very abundant• For every 1 seedless

plant, there are 10 seed plants

• Seed Plants• Have vascular tissue• Use pollen and seeds to

reproduce• Have roots, stems, leaves

Review of Vascular Tissue

• Vascular tissue- keeps plants upright, and supplies cells with food, water, and minerals

• Xylem- goes up, carries water

• Phloem- goes down, carries food

Ways of Reproduction• Unlike seedless plants (i.e. moss),

seed plants can live in any environment• Seedless plants have to live in

moist environments• Seed plants use the two following

structures to reproduce:• Pollen- tiny structures that

contain cells that will be sperm cells one day

• Seed- a structure that contains a young plant inside a protective covering that keeps the plant from drying out

Seed Structure and Dispersal• Inside of a seed is a partially

developed plant• Three main parts:

• Embryo- the young plant that develops from the zygote, or fertilized egg

• Cotyledon- the leaves of a seed; sometimes food is stored in the cotyledon

• Seed Coat- outer covering that protects the seed from drying out

• Fruit- protects the whole seed• What are the three ways in which

organisms move from place to place?• Seed Dispersal- Wind, water,

other organisms

Plant Growth• Germination- occurs when

the seed begins to grow again, and pushes out of the seed

• It is best that a seed plants itself away from its parent. Can you think of why would this be?• Does not have to

compete with its parent• Spreads its species out

over an area• Can you imagine if all of

the pine trees in the Adirondack region were only located in the schoolyard of Northville?

Roots• Three functions of roots:

• Anchor the plant• Absorb water• Store food

• Three types of roots• Fibrous- dense and tangled;

take up a lot of space• Examples: grass, onions,

corn• Taproot- one big, massive root

that branches off into little smaller hair-like roots• Examples: dandelions, carrot

Fibrous

Tap Root

Structure of Roots• Root Cap-

protects the root from injury as the root grows through the soil

• Root Hairs- increases surface area so that more water and minerals are absorbed; also helps to anchor the plant better

Stems• Stems- carries

substances between plants roots and leaves; holds leaves up towards the sun

• Two types of stems:• Herbaceous stem-

soft (ex. Daffodils)• Woody stem- hard

(ex. Maple tree, roses)• Cambium- located

in woody stems that is found towards the outside; makes new xylem and phloem

Ice Breaker

• What are the three functions of roots?

• What is the cotyledon in a seed?

• What are the two ways of reproduction in a seed plant?

Tree Studies• Examine the following wood

samples…what do you see?• Each ring represents one year

of growth• Dendrochronology- the study

of tree growth by examining annual rings• Annual rings- circles in a

tree that represent how old the tree is

• One dark ring and one light ring make up one full year

• Light ring- growth in spring; really rapid growth

• Dark ring- growth in summer/fall; slower growth

Summer/Fall

Spring

LeavesLeaves LeavesLeaves- capture the sun’s - capture the sun’s

energy and carry out the energy and carry out the food-making process of food-making process of photosynthesisphotosynthesis

Leaves vary greatly Leaves vary greatly depending on the treedepending on the tree Oak trees have really big leavesOak trees have really big leaves Pine trees have needlesPine trees have needles Palm trees have leaves that are Palm trees have leaves that are

big, but have small parts to itbig, but have small parts to it

Parts of a LeafParts of a Leaf CuticleCuticle- prevents water loss- prevents water loss StomataStomata- pores that open and - pores that open and

close to control when gases close to control when gases leave (Oleave (O22) and enter the cell ) and enter the cell (CO(CO22)) TranspirationTranspiration- the process by - the process by

which water evaporates from a which water evaporates from a plant’s leavesplant’s leaves

Stomata close during the dayStomata close during the day to prevent transpiration from to prevent transpiration from the heatthe heat

Stomata open at nightStomata open at night when when its cooler and there is less of a its cooler and there is less of a chance of transpirationchance of transpiration

Photosynthesis in LeavesPhotosynthesis in Leaves Photosynthesis occurs at the Photosynthesis occurs at the

top of the leaf, where there top of the leaf, where there are more chloroplastsare more chloroplasts

Section Four: Gymnosperm and Angiosperms

Gymnosperms vs. Angiosperms

• Think of a pine cone versus an apple• Although they are

structurally different, they both contain seeds

• Both are in different groups• Gymnosperms- produces

“naked” seeds • Seeds are not enclosed

within a fruit• Trees tend to have needle-

like leaves, and deep roots• Example: pine tree,

spruce tree

Types of Gymnosperms• Cycads- grow in subtropical

and tropical areas• All plants about 175 million

years ago were cycads• Conifers- cone-bearing plants

• Largest and most diverse of the gymnosperms

• Ginkgoes- only one living tree today called Ginkgo biloba

• Gnetophytes- live in dry areas• Can be either trees,

shrubs, or vines• The plant Welwitschia can

live for 1,000 years

Reproduction in Gymnosperms

• Cones- the gymnosperm reproductive structure that can be either male or female; covered in scales• Trees usually have both

the male and female parts, but some trees just have one or the other

• At the base of each female scale of a pinecone are ovules• Ovules- a structure that

contains an egg cell• This will develop into a

seed once it is fertilized

Reproduction in Gymnosperms• Steps of reproduction in a gymnosperm

are as follows…• Step One: Pollination- pollen

transfers from the male structure to the female structure

• Step Two: Fertilization- once the sperm meets the egg cell, the ovule closes off and seals it (the embryo forms)

• Step Three: Seed Development- female cones stay on the tree until they get mature; males fall off of the tree after they pollinate

• Step Four: Seed Dispersal- when the seed is mature, the scales open up and release the seed out into the air to be picked up, carried to a new place, and form into a new plant

Ice Breaker

• Roughly explain the reproductive cycle of a gymnosperm

Pretty Flowers of the Day

Buttercup Petunia

Angiosperms• Angiosperms-

flowering plants that have their seeds enclosed within fruits

• Flower- the main purpose of a flower is for reproduction

• Carries reproductive structures

• Attracts insects to help pollinate

Parts of Flowers• Sepal- located at the

base of the flower; when the flower has not bloomed yet, it is contained within the sepal

• Petals- colorful; this is the main part that attracts insects to the flower for pollination

Male Parts of the Flower

• Stamen- male reproductive part

• Anther- top part where the pollen is produced

• Filament- thin stalk where the anther sits on

Female Parts of the Flower• Pistil- female part of

the flower• Stigma (“sticky

stigma”)- top where pollen sticks

• Style- long tube where pollen travels down to fertilize ovaries

• Ovary- where the egg and sperm cells join; protects the seed as it grows

Reproduction in Angiosperms• Pollination-

• Pollen from an anther falls onto the “sticky stigma”

• The pollen then grows a long tube down the style to the eggs

• The sperm cells make their way down to the egg cells via the tube

• Fertilization- the sperm and egg cells form (to make a zygote) and then begin to make an embryo within a seed

• Fruit Development- as the seed develops in the ovary, the ovary then becomes a fruit• Fruit- a ripened ovary that

protects seeds

Major Groups of Angiosperms

• Recall that cotyledons are the first leaves of a seed, and a place where embryos can get their food

• Monocots- “one cotyledon”

• Dicot- “two cotyledons”

Differences Between Mono and Dicots

MonocotPlant Part

Dicot

One cotyledon

Seed Two cotyledon

Parallel veins LeafBranching

veins

Bundles of Vascular Tissue

Scattered

Stem Vascular Tissue

Bundles of Vascular

Tissue in Ring

Flower Parts in Threes

FlowerFlower Parts in Fours or

Fives

Ice Breaker

• What is the cotyledon difference between a monocot and dicot?

• What is the leaf differences between a monocot and dicot?

• Explain the reproduction in an angiosperm

Pretty Flowers of the Day

Tulip Water Lily

Section 5: Plant Responses and Growth

Tropisms• Think of…

• Being pricked by a needle• You try to move away from the

needle because it hurts• Being really cold, and a fire in the

fireplace is burning in the next room• You move to the fire to warm up

• Both the needle’s pain and the fire’s warmth is called a stimulus

• Tropism: a plant’s response toward or away from a stimulus

Types of Tropisms• Thigmotropism- a

plant’s response to touch• Example: vines

crawling up a wall, Venus Fly Trap

• Phototropism- a plant’s response to light

• Geotropism- a plant’s response to gravity

Yum!

• Annual- flowers that complete their life cycle in one year (only live for one year)• Examples- marigolds,

petunias• Biennial- flowers that complete

their life cycle in two years (only live for two years)• Examples- Celery, foxgloves

• Perennials- flowers that live for more than two years• Example- Purple Coneflower,

Maple tree

Life Spans of Angiosperms

Video

Plants and People