Transcript Living Things - Somerset Area School District

Introduction to Plants
Table of Contents
The Plant Kingdom
Photosynthesis and Light
Mosses, Liverworts, and Hornworts
Ferns, Club Mosses, and Horsetails
Introduction to Plants
What is a Plant?
-Multicellular organisms with tissues
and organs.
-Contain chlorophyll inside chloroplasts
and can make food.
-Can not move from place to place.
-Made of eukaryotic cells with cell
walls.
Introduction to Plants - The Plant Kingdom
Plant Cell
Chloroplast
Nucleus
Vacuole
Cell Wall
Cell Membrane
Introduction to Plants - The Plant Kingdom
Plant Cell Structure Activity
Click the Active Art button to open a browser window and
access Active Art about plant cell structure.
Introduction to Plants
Adaptations to Land
-To move to land, plants had to develop
adaptations to solve the following problems:
*Prevent water loss —cell walls made of
cellulose help prevent water loss. Most
land plants also have a waxy covering
called a cuticle on their stems and leaves
that also aids in preventing water loss.
*Obtain water and nutrients from soil —
plants evolved roots.
Introduction to Plants
*Transport Materials —water moves up
and food moves down through most
plants through tube-like vascular tissue.
*Support their own weight —cell walls
and vascular tissue provide structure and
support. Stems and roots then evolved.
*Reproduction —the most successful
land plants evolved ways to reproduce
without water (seeds).
Introduction to Plants - The Plant Kingdom
Water Loss in Plants
The graph shows how much
water a certain plant loses
during the hours shown.
Introduction to Plants - The Plant Kingdom
Water Loss in Plants
Reading Graphs:
What variable is plotted
along each axis?
Horizontal axis–time of day;
vertical axis–water loss.
Introduction to Plants - The Plant Kingdom
Water Loss in Plants
Interpreting Data:
According to the graph,
during what part of the
day did the plant lose the
most water? The least
water?
Most–midday; least–in the
evening.
Introduction to Plants - The Plant Kingdom
Water Loss in Plants
Drawing Conclusions:
What could account for
the pattern of water loss
shown?
The plant seemed to lose
the most water during the
sunniest or warmest parts of
the day.
Introduction to Plants - The Plant Kingdom
Water Loss in Plants
Predicting:
How would you expect the
graph to look from 10 p.m.
to 8 a.m.? Explain your
reasoning.
The line graph would
descend during the night
and then rise again in the
morning hours, because the
water loss is less during the
night when there is no sun.
Introduction to Plants
Origin of Plants
-Evolved from one-celled,
plant-like protists in the ocean
(Green Algae)
*Fossil record is sketchy
because most plants decay
before they form fossils.
*Oldest plant fossils are
about 400 million years
old. They had no leaves and
their stems grew
underground.
Introduction to Plants
Photosynthesis
-All plants make food through the process of
photosynthesis.
*During photosynthesis, plants use energy
from sunlight to change carbon dioxide
and water into sugar and oxygen.
Introduction to Plants
1. Sunlight or “white light” is made of all of
the colors of the rainbow (the visible
spectrum).
Introduction to Plants
2. Plants absorb most of these colors
except green. Green light is reflected
by the pigment known as chlorophyll.
3. Other plant pigments reflect other
colors and are called accessory
pigments. We see them mostly in the
fall, when plants stop making
chlorophyll.
Introduction to Plants - Photosynthesis and Light
The Photosynthesis Process
-In photosynthesis,
the energy in sunlight
is used to make
sugar and oxygen
from carbon dioxide
and water.
Introduction to Plants
The Big Picture of Photosynthesis
-Water enters through the roots of the plant.
-Carbon dioxide enters through tiny openings
in the leaves of the plant called stomata.
-They travel to the chloroplasts where they
are changed into a special sugar, called
glucose, and oxygen.
Introduction to Plants
-Glucose is the plant’s food. It is broken
down, just like our food, to give the plant
energy to grow, develop, respond and
reproduce.
-Most of the oxygen is released also
through the stomata of the leaves and
used by other organisms.
Introduction to Plants - Photosynthesis and Light
The Photosynthesis Process Activity
Click the Active Art button to open a browser window and
access Active Art about the photosynthesis process.
Introduction to Plants
The Photosynthesis Equation
-The many chemical reactions of
photosynthesis can be summarized by this
equation:
light energy
carbon dioxide
+
water
sugar
+
oxygen
light energy
6CO2
+
6H2O
C6H12O6
+ 6O2
Introduction to Plants - Photosynthesis and Light
Photosynthesis
Click the Video button to watch a movie about
photosynthesis.
Introduction to Plants
Photosynthesis Video
13 minutes with video quiz that follows
Introduction to Plants - Photosynthesis and Light
Previewing Visuals
Preview Figure 9. Then write three questions that you have
about the diagram in a graphic organizer like the one below.
As you read, answer your questions.
Water Vascular System
Q. How is sunlight involved in photosynthesis?
A. The energy in sunlight is used to make sugar.
Q. Why does a plant need sugar?
A. The plant uses energy from the sugar to carry out life
functions.
Q. How does the plant use the water its roots take in?
A. Water molecules combine with carbon dioxide to form
sugar and oxygen during photosynthesis
Introduction to Plants
Classification of Plants
-The Plant Kingdom is divided into nine divisions
*The first division includes nonvascular
plants. Nonvascular plants have
no vessels (vascular tissue) for transporting
food and water. Therefore, they are all very
small and grow in damp shady places.
They include:
1. Division Bryophyta: mosses,
liverworts, and hornworts.
Introduction to Plants
Classification of Plants
*The remaining eight divisions are all
vascular plants. Vascular plants have
vessels (vascular tissue) to transport
water and materials and help support the
plant. Therefore they can grow very tall
and are better suited to all land habitats.
Some reproduce using spores and some
use seeds.
Introduction to Plants
This chapter will look at the three divisions
of seedless vascular plants.
1. Division Lycophyta —club mosses
2. Division Sphenophyta —horsetails
3. Division Pterophyta —ferns
Introduction to Plants
Division Bryophyta
-Mosses are the most
common type of bryophyte.
*10,000 different species
*All are simple, rootless
plants with leaf-like growths
in a spiral around a stalk.
*Root-like threads called
rhizoids replace true roots
and hold the moss in place.
*Range in size
from 2-5 cm
in height
Introduction to Plants
Division Bryophyta
•Liverworts —simple,
rootless plants that have a
flattened, leaf-like body.
Their name means, “liver
herb” and in the Middle
Ages, people believed this
plant looked like one’s liver.
Introduction to Plants
Division Bryophyta
•Hornworts —small plants
with flat, round, leaf-like
structures. It’s sporophyte
looks like an animal’s
horn. They live near lakes
and rivers.
Introduction to Plants
Importance of Bryophytes
-Bryophytes such as mosses and liverworts
are often called pioneer plants because
they are the first to grow in new or
disturbed areas.
-Nonvascular plants like them were also
probably the first land plants to evolve
millions of years ago.
-Many people use peat moss from bogs in
agriculture and gardening.
Introduction to Plants
Complex Life Cycles
-Simple plants like mosses and other
bryophytes have complex life cycles that
include two different stages:
the sporophyte stage and the gametophyte
stage.
Introduction to Plants - The Plant Kingdom
Complex Life Cycles
Introduction to Plants - Mosses, Liverworts, and Hornworts
Mosses
-A moss gametophyte is
the green leafy part of the
plant and the root-like
rhizoids. There are separate
male and female
gametophytes.
-The moss sporophyte is
made of a stalk and a
capsule. It grows from the
zygote cell and will produce
new spores that will grow
into new gametophytes.
Introduction to Plants
Another look at the
moss reproduction
process.
Introduction to Plants - Mosses, Liverworts, and Hornworts
Identifying Main Ideas
As you read this section, write the main idea–the biggest or
most important idea–in a graphic organizer like the one
below. Then write three supporting details that give examples
of the main idea.
Main Idea
Nonvascular plants include…
Detail
Mosses
Detail
Liverworts
Detail
Hornworts
Introduction to Plants - Mosses, Liverworts, and Hornworts
Links on Nonvascular Plants
Click the SciLinks button for links on
nonvascular plants.
Introduction to Plants - Ferns, Club Mosses, and Horsetails
Characteristics of Seedless Vascular Plants
Ferns, club mosses, and horsetails also reproduce
using spores not seeds. However, they have
vascular tissue which means they can grow
much taller. There are three divisions of
seedless vascular plants.
Introduction to Plants
Division Lycophyta
Division Lycophyta— also
known as club moss.
Produce spores in structures
that look like tiny pinecones.
Sometimes called ground
pine.
Introduction to Plants
Introduction to Plants
Division Sphenophyta
Division Sphenophyta—
also known as horsetails.
Stems are jointed with a
hollow center. They
contain silica (a gritty
substance found in sand).
They were used by
pioneers to scour their
pots and pans.
Introduction to Plants
Introduction to Plants
Division Pterophyta
Division Pterophyta —
includes all species of
ferns. Largest group of
seedless vascular plants.
Ancient species were huge
(25 meters). Today, the
largest species are 3-5
meters. These ancient fern
forests formed today’s coal
deposits.
Introduction to Plants - Ferns, Club Mosses, and Horsetails
Characteristics of Ferns
-Most ferns have underground stems in
addition to roots. The leaves, or fronds,
grow above ground.
Introduction to Plants
Fern Reproduction
-Ferns and other seedless vascular plants
also reproduce using a sporophyte and a
gametophyte generation.
Fern sporophyte with
spore cases called sori
Fern gametophyte with
young sporophyte beginning
to grow
Introduction to Plants
Complex Life Cycle of Ferns
-The sporophyte is the fern leaf or “frond”.
On the underside of the frond are spore cases
called sori. These release thousands of spores.
A spore grows into a heart-shaped gametophyte
It is held in place by root-like structures called
rhizoids and has both sperm and egg cells on
it. They unite and a new sporophyte begins to
grow.
Introduction to Plants
Introduction to Plants
Wrap-up
-Both mosses and ferns rely on water for
reproduction because the sperm cells must
swim to egg cells. Therefore, these plants live
only in fairly moist areas. It wasn’t until plants
evolved seeds for reproduction that they truly
became successful in all land habitats.
-Seed producing vascular plants include all
other plants not discussed in this chapter. We
will be studying them next.
Introduction to Plants - The Plant Kingdom
Building Vocabulary
A definition states the meaning of a word or phrase by telling
about its most important feature or function. After you read
the section, reread the paragraphs that contain definitions of
Key Terms. Use all the information you have learned to write
a definition of each Key Term in your own words.
Key Terms:
photosynthesis
cuticle
nonvascular
plant
sporophyte
tissue
gametophyte
vascular
vascular tissue
plant
chloroplast
chlorophyll
fertilization
vacuole
zygote
Examples:
Sunlight
One
Plants
that
provides
lack athat
well-developed
the
helps
energy
a plant
for
this
system
reduce
food-making
of
water
tubes
loss
foris
In
theadaptation
sporophyte
stage,
the
plant
produces
spores,
process,
a
transporting
waxy,
called
photosynthesis.
and
layer
other
called
materials
the
cuticle,
are known
which as
tiny
cellswaterproof
thatwater
can
grow
into
new
organisms.
covers
nonvascular
the how
leaves
plants.
of most
plants.
No
matter
large
or
small
a plant
its cellstwo
are
In the
gametophyte
stage,
the
plant is,
produces
Vascular
tissue
is a system
of tubelike
structures
organized
into
tissues—groups
of egg
similar
cells
that
Plants
true
vascular
are
called
vascular
kinds ofwith
sex
cells:
sperm tissue
cells and
cells.
inside
through
whichinwater,
minerals, and
perform
a specific
function
an organism.
plants.a plant
food move.
Chloroplasts,
which
look something
like green
jelly
Biologists
studied
a green
pigment
called
chlorophyll,
Fertilization
occurs
when
a
sperm
cell
unites
with
an
beans,
are
the
structures of
in plants,
which food
is and
made.
found
in
the
chloroplasts
algae,
some
egg cell.
A
vacuole is a large storage sac that can expand and
bacteria.
A
fertilized
is called a zygote.
shrink
like aegg
balloon.
Introduction to Plants - Ferns, Club Mosses, and Horsetails
Asking Questions
Before you read, preview the red headings. In a graphic
organizer like the one below, ask a what, how, or where
question for each heading. As you read, write the answers to
your questions.
Ferns, Club Mosses, and Horsetails
Question
Answer
What are the characteristics of
seedless vascular plants?
Seedless vascular plants have
vascular tissue; they do not produce
seeds; they reproduce by releasing
spores.
How do ferns reproduce?
Ferns reproduce by spores that form
on the underside of their fronds.
How do club mosses differ from
true mosses?
Club mosses have vascular tissue.
Introduction to Plants
Graphic Organizer
Characteristic
Moss
Fern
Size
Small and low
Can be tall
Environment
Moist
Moist
Body parts
Rootlike, stemlike,
leaflike structures
True roots,
stems, and leaves
Familiar generation
Gametophyte
Sporophyte
Is true vascular
tissue present?
No
Yes