PLANT UNIT Chapters 22-25

PLANT UNITChapters 22-25

Plant Diversity

Roots Stems and Leaves

Reproduction

Plant Response and Adaptations

Objectives

• Identify methods of seed dispersal.

• Plant leaf size and sunlight amounts – effects of.

• Concepts of diversity in plants.

• Plant alternation of generation.

• Plant requirements• Evolution of plants

•  

•  • This seed is best dispersed

by —•    • A water • B birds • C wind • D animals

Seed Dispersal

Seeds can be dispersed in a number of different ways. They may be carried by wind, water or animals. Some plants even shoot the seeds out explosively. Seed size is an important factor

• Which of these characteristics might help a plant species survive in an area with limited sunlight?

•  • FBright flowers• GLarge leaves• HShort stems• JThick cuticles

Plant Diversity Chapter 22 pg 550

• What is a plant

• # of cells

• type of cells

• shape of cells

• auto or hetero – trophs

Plants have ALTERNATION OF GENERATIONS… ?

• Plants have a two phase reproductive cycle:• Known as Alternation of Generations• gametes and spores – reproductive cells• The diploid phase is know as sporophyte 2N stage

the haploid phase is known as gametophyte 1N• When two gametes cometogether – sexual

repoduction has occurred. Example egg +sperm

Early plants required water…

• Mosses and ferns

What they need to survive..

• What do you think ?

Plants over time

• Mosses to ferns to cone-bearing(produced seeds) to eventually flower plants(which produced fruit)

Overview of Plant Kingdom pg 555

• Earth's oldest living inhabitant of Gia – Earth "Methuselah" at 4,767 years, has lived more than a millennium longer than any other tree

• Discovered by Dr. Edmund Schulman

• White Mountains of California

• Dating through tree-ring growth

22-5 pg 569 AngiospermsLesson Goals

• What are characteristics of angiosperms ?

• What are monocots and dicots

• What are three categories of plant life spans ?

Let’s talk flowers – reproductive structures

• ANGIOSPERMS : Cretaceous Period – have fossils from 120 million years ago.

Why do you think angiosperms(means enclosed

seeds) took over species numbers : advantages ?

• Color• Smell

• Fruit/ protection and possible dispersal

• Seed protected by outside coat• Spreading of seeds

Chapter 24 Flowering Parts

Flower part Part function

Petal Petals are used to attract insects into the flower, they may have guidelines on them and be scented.

Pistil Female parts F : stigma

Sticky part of flower where pollen is deposited by wind, insect or humming bird

F:Style

Tube which pollen passes thru.

F: Ovary /Ovule

The Ovary is like the egg in animals and once fertilisation has taken place will become the seed. Fruit will protect.

Stamen: Male parts

M: Anther Covered with pollenM: Filament Holds the anther in position for pollen removal from anther

Sepal Sepals protect the flower whilst the flower is developing from a bud.

receptacle

Holds all flower parts

NAME MY PARTS…A IS…

•

• •

PETAL

• •

PETAL

ANTHER

• •

PETAL

ANTHER

FILAMENT

• •

PETAL

ANTHER

FILAMENT

SEPAL/CALYX/RECEPTCLE

• •

PETAL

ANTHER

FILAMENT

SEPAL/CALYX/RECEPTCLE

OVARY

• •

PETAL

ANTHER

FILAMENT

SEPAL/CALYX/RECEPTCLE

OVARY

• •

PETAL

ANTHER

FILAMENT

SEPAL/CALYX/RECEPTCLE

OVARY

STYLE

• •

PETAL

ANTHER

FILAMENT

SEPAL/CALYX/RECEPTCLE

OVARY

STYLE

STIGMA

PETAL

flower

Diversity of AngiospermsBased on cotlyedon: first leaf or pair of

leaves.

Compare seeds :cotlyedons, roots, leaves and stems

Compare leaves, stems, roots.

Compare vascular bundles and support tissue organization.

Diversity of angiosperms:Woody vs Herbaceous plants

• Woody: • Thick cells with thick

cells walls that support the plant body

• Trees, shrubs and vines

• Herbacious• Thinner, smooth,

smaller in need of support

Diversity of Angiosperms:Annuals, Biennials and

Perennials• Annuals – die after

seed production.

examples: dandelions

• Biennials –Take two years to make productive cycles

examples:Hollyhock, Echinacea

• Perennials – return year after year to reproduce.

examples: trees, shrubs, roses

TAKS Review

• Pg 577 1-4

Chapter 23 Roots, Stems and Leaves

• Pg 578• What are three principal

organs and tissues of seed plants

• What are the three main tissue systems of plants

• What specialized cells make up vascular tissue

• How does meristematic tissue differ from other plant tissue

Structures of seed plantsWhat are the purposes of each ?

• Roots • Stems• Leaves

What they need to survive..

• What do you think ?

Plant Tissue• Dermal Tissue Epidermal : single layer

covered with cuticle : waxy for protection from dehydration.

Trichomes : pubescent Root hairs: increase

surface area for water absorption

Guard Cells: Stomata: regulate water and gases from leaves

Vascular Tissue

• Xylem• Carries water: • Carries from

roots to leaves

• Phloem• Carries food :

sieve tubes.• Carries from

leaves to roots

• Ground Tissue

• Parenchyma in leaves : bundles

• Collenchuma : cells walls

• Sclerenchma : tissue tough

Tissue GrowthOnly occurs in meristematic

tissue• MeristematicUnspecialized cells

produced in the meristems : cluster of continual growth throughout a plants life.

Found at tips of growth areas such as buds, and roots

• Apical Meristem

Undifferentiated on stems and roots.

CELLS HERE REPRODUCE BY

MITOSIS

23-2 Roots and Root Structures

• Tap vs Fibrous benefits ?

• How do roots help prevent erosion ?

Root Structure

Stem Comparison

Dicot or Monocot? (Circle)

• Dicots have pith•

•

23-4 leaves

Leaf cross section

• Functions

• Stomata open and close in response to water vapor into and out of leaves.

• So its hot and dry, what do they do ?

• Its night time , what do they do ?

Taks Review pg 607 #1-4

Chapter 24 Reproduction of Seed Plants• We saw this in earlier

slides.

• What are other methods of reproduction in plants ?

• Vegetative Reproduction – one parent -asexual

• Plant Propagation

Grafting cuttings

Taks preparation pg 631 1-4

CELL COMPARISON

PLANT CELL

ANIMAL CELL

Plant Behavior - TROPISMS

Plant Behavior - TROPISMS

Plant Behavior - TROPISMS

Plant Chemicals

• Hormones

• Auxin

• Light responses

• Cell growth

increases –

which side

do you think ?

Chapter 25 Plant Responses and Adaptations pg 632

• Objectives:

• What are plant hormones

• How do each of them affect plant growth?

• What are the plant tropisms

• How do plants prepare of seasons

• How have plants adapted to environments

• Defense against insects

Plant Hormones: Substances that control an plants patterns of growth and development and

plants responses to environmental conditions

Auxins• Promotes phototropism• Produced in the apical

meristem at the tip of the stem.

• Stimulate cell elongation.• Also influenced by gravity-

geotropism• Also stimulated by

removal of apical meristem• Herbicides are also auxin

enhanced.

Cytokinins

Stimulate cell division and the growth of lateral buds, and cause dormant seeds to sprout. Include the delay of aging leaves .

Gibberellins

• Increase sizes

Ethylene

• Fruit ripening hormone – in gas state

Tropisms

Gravitropsim

Phototropism

Thigmotropism

Rapid Response

Winter Dormancy/Photodormancy

• Due to change in light and temperature. Deciduous plants turn off photosynthetic pathways. Leaf abscission occurs and the photochrome absorbs less light and auxin production lowers and the leaf shuts off and chlorophyll production stops and the leaf’s water in extracted and the petiole seals off and the leaf falls to the ground

Adaptations of Plants• Water Plants :Aquatic Plants : many have tissues

with large air filled spaces through which oxygen can diffuse.

• Salt tolerate plants - mangrove• Desert Plants - succulents cactus, yucca• Carnivorous plants –pitcher plant, Venus fly trap• Parasites – mistletoe• Epiphytes – grow on other plants spanish moss • Chemical Defense: milkweed and monarchs

Taks Review pg 653 1-3