Seed Plants - Mr. Wright`s Class Website

Report
Mr. Wright, 2011
Plant Diversity
 We are going to be spending the next couple of weeks
looking at the basic characteristics of plants.
 As you will see, there is a lot of diversity in this
kingdom… they are more than “just plants”.
 Today we are going to watch a video that shows some
pretty unique and interesting plants, and you will see
just how diverse this kingdom is!
Section 22.1
The Kingdom Plantae
 In order to be classified as a plant, an
organism MUST be:
 Multicellular
 Eukaryotic
 Cell walls made of cellulose (sugar)
 Autotrophic (photosynthesis)
Plant Life Cycles
 Plants, like the protists and fungi we’ve
talked about before, go through
alternation of generations during their
life cycles.
 Plants have both a haploid and a diploid
stage.
 In plants, these stages have special
names.
Plant Life Cycles
 Gametophyte – a haploid individual that produces
gametes.
 These gametes will combine to form the diploid
sporophyte.
 Sporophyte – A diploid individual that produces
haploid spores through meiosis
 The spores then grow into gametophytes.
Evolution of Plants
 The first plants evolved
from algae.
 Algae spend their whole
lives in water, while
plants evolved to live on
land.
 In order to survive on
land, plants needed to be
able to do three things.
Three adaptations for land:
 Plants need to be able to absorb nutrients from
their surroundings.
 Plants evolved roots for just this purpose.
 The very first plants did not have roots. Instead,
they got their nutrients from symbiotic fungi
(mycorrhizae).
Three adaptations for land:
 Plants need to be
able to prevent
water loss to keep
from drying out.
 Plants evolved a
waxy, watertight
covering called a
cuticle.
Three adaptations for land:
 Plants need to be able to disperse (spread)
themselves across dry land.
 Several ways plants can do this:
 Wind
 Water
 Other Organisms
Plant Groups
 Plants evolved to form 4 main groups.
 We will look at in terms of seedless plants and seed
plants.
Daily Assignment – Comparing Plants
 The next three slides will include pictures of
two different plants.
 Look at each plant. How are they different?
How are they similar?
 Make a Venn Diagram for each pair of plants
to show these similarities/differences in a
handy dandy graphic organizer.
Comparing Plants
Maple Tree
Elm Tree
Comparing Plants
Gingko Tree
Pine Tree
Comparing Plants
Venus Fly Trap
Apple Tree
Section 22.2 and 22.3
Seedless Plants
 Seedless plants are the most primitive plants.
 They can be divided into two smaller groups:
 Nonvascular (bryophytes)
 Vascular
 The very first plants were nonvascular seedless
plants, and vascular plants evolved from there.
Nonvascular Plants - Bryophytes
 These plants do not
have vascular tissue
(veins) to transport
water throughout
the organism.
 Examples include
mosses, liverworts,
and hornworts.
Nonvascular Plants - Bryophytes
 Water is transported through the plant by osmosis and
diffusion.
 This means water moves very slowly and over short
distances.
 This limits the size of these plants – they simply can’t
move water far enough quickly enough to grow large.
Vascular Plants
 An important step in the evolution of plants was the
development of vascular tissue (veins).
 This is what makes it possible for plants to move food
and water over great distances, allowing them to grow
tall.
 The most well known member of this group are ferns.
Vascular Plants
 Two types of vascular
tissue:
 Xylem – transports
water through a
plant
 Phloem – transports
food (nutrients and
sugars) through a
plant
Daily Assignment –
Nonvascular and vascular plants under the microscope
 I have set up several microscopes with a
variety of slides on them.
 Some of the slides are from
nonvascular plants, and some are from
vascular plants.
 Complete the worksheet given to you
and turn it in for today’s grade.
Should look something like this…
Sections 22.2 and 22.3
Daily Assignment –
Diagramming a Seedless Life Cycle
 Color the gametophyte stage one color, and
the sporophyte stage another. Be sure to
include a key so I know which is which.
 Be sure to label all parts, particularly the
archegonium, egg, antheridium, sperm,
zygote, sporangium, and spores.
 In your own words, describe what is
happening at each step in the table
provided.
Reproduction in Seedless Plants
 Plants produce both male gametes
(sperm) and female gametes (eggs) –
sometimes both on the same plant!
 Haploid!
 These are produced by specialized
structures on the haploid
gametophytes.
Reproduction in Seedless Plants
 Archegonium – the female
reproductive structure in plants,
produces a single egg.
Reproduction in Seedless Plants
 Antheridium – the male reproductive
structure in plants, produces sperm
cells
Reproduction in Seedless Plants
In seedless plants, the sperm cells
need to reach the egg cell
somehow.
The only way they can do this is if
there is water covering the plant
for them to swim through.
 REQUIRE WATER TO
REPRODUCE!!!!!
Reproduction in Seedless Plants
The two gametes will combine
to form a zygote (fertilized egg).
This grows into the diploid
sporophyte.
Reproduction in Seedless Plants
 Sporangium – a
specialized structure
where spores are
produced in the
sporophyte
 Spores are produced
by meiosis, so they
are haploid.
 Will grow into new
gametophytes.
Reproduction in Seedless Plants
Thus a cycle is formed, and it
repeats over and over again!
Weekly Wrap-up Activity
Daily Assignment – Act It Out
 You will work in a group of 4-6 people of your
choosing. You MAY want to try to have both genders
represented.
 This week, we have spent a lot of time talking about
the most basic plants - the seedless plants. Before we
begin talking about plants with seeds, I’d like to review
everything we’ve done up to this point.
 General Plant Characteristics
 Nonvascular vs. Vascular plants
 The Life Cycle of a Seedless Plant
 I will give each group one of the topics listed above.
Daily Assignment – Act It Out
 Your group will then create a play/skit about the topic given
to you.
 Skits should be fairly short… 5 minutes maximum.
 Every group member must be involved in some manner.
 Props - anything in my room is yours to use.
 How you set your play up is your choice – maybe you will play
the plants themselves, or maybe your play takes place in a
classroom.
 Be creative and maybe you can have some fun with it.
 You will perform these at the end of class, which gives you
about 30 minutes to get things put together.
 You may write a script, if you like, but it’s for your own use
only… your grade will be on the performance itself.
Section 22.4
Seed Plants - Groups
 Seed plants are divided into two smaller
groups – gymnosperms and angiosperms.
 Both of these groups are vascular plants, and
they all produce seeds to aid in the survival
and dispersal of their offspring.
Seed Plants - Groups
 The difference between the two groups is how they
develop their seeds – angiosperms have fruit, while
gymnosperms do not.
 Gymnosperm = “naked seed”
 Angiosperm = “covered seed”
Seed Plants - Reproduction
 Seed plants do NOT require water to reproduce.
 They have other methods for getting sperm and egg cells
together.
 Because of this fact, they can live almost anywhere,
including very dry areas.
Seed Plants - Reproductions
 Plants have both male and female parts.
 They often look completely different from
each other, as do the structures they are kept
in.
Seed Plants - Reproduction
 In seed plants, male gametes are kept in side of pollen
grains.
 They don’t have to swim towards the egg… instead,
they are carried by something else.
 Wind
 Insects
 Animals
 Pollination – when the pollen is carried to the female
structure.
Seed Plants - Reproduction
 A tube emerges from the pollen grain and attaches
to the ovule, allowing sperm to travel into the egg.
This is fertilization.
 The fertilized ovule will then develop into a seed.
 Plants CAN self-pollinate.
Seed Plants - Reproduction
 A seed is a fertilized embryo surrounded by a
protective layer and food supply.
 Protective layer = seed coat
 Not only protects it, but keeps it from drying out
Gymnosperms – Cone Bearers
 Gymnosperms are conifers.
 Any plant that does not have its seeds inside of fruit
falls in this classification.
 Many types of trees, but not all.
Daily Assignment:
Seed Plant Reproduction
 On a blank piece of paper, put the following steps in order.
Draw a picture of each step as you go.
 A tube emerges from the pollen grain and attaches to the





ovule.
Antheridia produce sperm cells in the form of pollen grains,
while archegonia/ovaries produce egg cells in the form of
ovules.
Pollen grains land on the female reproductive structure.
The ovule is fertilized and becomes a seed.
Pollen grains are picked up by something (wind, animals,
water) and carried elsewhere.
The seed results in a new plant being formed.
 Complete the vocabulary review crossword puzzle.
 Staple both pages together and turn them in for today’s
grade.
Section 22.5
Angiosperms
 Angiosperms develop unique reproductive organs
known as flowers.
 Thus, they are known as the flowering plants.
 These attract insects and animals to aid in pollination.
Angiosperms
 Flowers have ovaries which surround and protect the
seed.
 After fertilization, these ovaries swell up and develop
into fruit.
 This aids in dispersal – the plant wants it to get eaten so
that it can be carried far distances before getting pooped
out.
Classifying Angiosperms
 Angiosperms are divided into two classes
based on their seeds – the monocots and
dicots.
 Monocots – have one seed leaf (called a
cotyledon)
 Dicots – have two seed leafs
Monocots vs. Dicots
 Besides the difference in the number of seed leaves,
there are other differences between these two groups
as well.
 Monocots usually have parallel venation, while dicots
have net venation.
Monocots vs. Dicots
 Monocot flowers tend to have their parts in
multiples of 3, while dicot flower parts tend
to be in multiples of 4 or 5.
Monocots vs. Dicots
 Monocots tend to have fibrous root
systems, while dicots tend to have one
large taproot.
Daily Assignment – Fruit Lab
 Today, we will look at many different types of fruit.
 We will attempt to tell how they are classified based on
what we can see inside the fruit.
 Follow the instructions on the lab worksheet given to
you and turn in once finished.
 Please be careful with the fruit given to you as supplies
are limited.
 Once you are finished you may eat what you have if
you want to. Enjoy!
Section 24.1
Structure of a Flower
Structure of a Flower
 Stamen – the male reproductive structure of a flower
that produces pollen and consists of an anther at the
tip of a filament
 Anther – the tip of a stamen, which contains the pollen
sacs where pollen grains are formed.
 Filament – holds the anther
Structure of a Flower
 Pistil – the female
reproductive part of
a flower that
produces seeds and
consists of an ovary,
style, and stigma.
 Also known as
carpals
Structure of a Flower
 Ovary – contains the
ovules, where eggs are
produced.
 Style – a narrow stalk
coming off of the ovary
 Stigma – sticky place at
the top of the style where
pollen lands
Structure of a Flower
 Petals – brightly colored tissue surrounding the
reproductive parts.
 Designed to attract insects and other pollinators.
 Sepals – small green leaves below the petals
 These are what cover the bud and protect the flower
before it opens.
Daily Assignment: Flower Dissection
 Today you will dissect a flower and look at the different
parts that it has.
 Follow the instructions on the lab sheet and fill out the
information as you go along.
 RULES FOR DISSECTING:
 Thou shalt not screw around with the scalpel – if
you do, I’ll take it from you, you’ll get a zero, and you
won’t be doing any more dissections this year.
 Thou shalt keep all materials on thy towel and
dispose of them when finished.
 Thou shalt clean up after thyself.
 Thou shalt not eat anything.
Section 25.2 and 25.3
Tropisms
 The responses of plants to external stimuli are called
tropisms.
 Greek for “turning”
 Think of it as plant behavior.
Tropisms
 Gravitropism
 Stems will ALWAYS grow against the force of gravity.
 Roots will ALWAYS grow with the force of gravity.
 In other words, stems always grow up and roots always
grow down.
Tropisms
 Phototropism
 Plants will always grow towards a light source.
 Some plants will even turn during the day to face the sun
at all times.
Tropisms
 Thigmotropism
 Response to touch.
 Examples:



Vines use it to wrap around another tree.
Leaves may fold closed when touched.
Venus fly trap’s close shut when hairs are triggered.
Winter Dormancy
 Dormancy – the period in which a plant’s growth and
activities stop.
 Photosynthesis becomes less effective, so plants stop




those pathways altogether.
Leaves become pointless, so the plant is better off
without them… they lose too much water!
Chlorophyll disappears, causing change in color.
All sugars and water are extracted from the leaves.
The plant is completely sealed off from the plant and
eventually will fall off.
Nutrition Specialists
 Why are some plants carnivorous?
 These plant still do photosynthesis.
 However, they live in nitrogen-poor environments, and
they need that nitrogen to survive.
 Thus, they have evolved to get it from other sources.
Nutrition Specialists
 Parasites
 Some plants extract water and nutrients directly from
other plants at their expense.
 Some parasitic plants don’t even have chlorophyll!

These rare cases would be plants that are NOT autotrophic.
 Example:
Daily Assignment:
Vocabulary Review Time!
 We have gone through a lot of new vocabulary this
chapter, as usual.
 This seems to be what trips people up the most so we
are going to spend some extra time on it this time
around.
 We will do this by playing a vocabulary game:
 ASK ENGLISH DEPARTMENT FOR VOCABULARY
GAME IDEAS!!!

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