Transcript Plants - Cloudfront.net

Plants
Plant Evolution
• Evolved from green algae
(450 mya)
• Green algae ancestor
– Multicellular body
– Cells w/ channels to
communicate
– Reproduce w/ sperm &
egg
• Early plants
– Low growth
(nonvascular)
Land Adaptations
• Retain Moisture
– Early plants grew near waters edge
– Cuticle: waxy coating
Land Adaptations
• Transporting Resources
– Vascular system: tissue to transport nutrients
• Up from the roots (ex: water)
• Down from the leaves (ex: sugars)
– Allows taller growth
Land Adaptations
• Growing upright
– Large plants need to support own weight
– Lignin: hardens cell wall; gives wood strength
Land Adaptations
• Reproduction on land
– Pollen: carried by wind/animals
– Seeds: hard coat protects embryo inside
Alternation of generations (In general)
• Diploid zygote created
• Zygote grows into a
sporophyte
• Haploid spores created by
meiosis
• Spores grow into
gametophyte
– Male gametophyte creates
sperm
– Female gametophyte
creates egg
• Sperm and egg fuse to
make a diploid zygote
• Cycle restarts
Kobe Kuiz
1) What traits do plants and plant-like protista share?
2) Name 4 adaptations that plants have for life on land.
3) Which plant adaptation allows them to carry nutrients to great
heights?
4) Which plant adaptation allows them to retain moisture?
5) What is the purpose of lignin?
6) What is the chromosome combination for the sporophyte stage?
7) What is the chromosome combination for the gametophyte
stage?
8) What does the gametophyte stage create?
9) What does the sporophyte stage create?
Group 1: Seedless, Nonvascular Plants
• Live in moist
environments to
reproduce
• Grow low to ground to
retain moisture
(nonvascular)
• Lack true leaves
• Common pioneer
species during
succession
• Gametophyte most
common (dominant)
• Ex: Mosses, liverworts,
hornworts
Moss Life Cycle
1)Moss
gametophytes
grow near the
ground
(haploid stage)
2) Through water,
sperm from the male
gametophyte will
swim to the female
gametophyte to
create a diploid
zygote
3) Diploid sporophyte
will grow from zygote
4) Sporophyte will
create and release
haploid spores
...
sporophyte
zygo
egg
te
zygo
egg
te
zygo
egg
te
male male
female
zygo
egg
te
female female
gametophyte
male
female male
5) Haploid
spores land
and grow into
new
gametophytes
6) The process
repeats
gametophyte
ground
...
sporophyte
zygo
egg
te
zygo
egg
te
zygo
egg
te
male male
female
zygo
egg
te
female female
gametophyte
male
female male
Group 2: Seedless, Vascular Plants
• Grow taller than mosses
– Vascular system allows
nutrient transport to
greater heights
• Live in moist environments
(to reproduce)
• Sporophyte creates spores
• Spores land and grow into
gametophyte
• Gametophyte creates sperm
& egg
• Zygote begins sporophyte
again
• Ex: Ferns, Club mosses,
Horsetails
Fern Life Cycle
1) Sporophyte creates and releases haploid spores
.
.
. .
Adult
Sporophyte
(diploid)
ground
2) Haploid spores land in the soil
ground
3) From the haploid spores, gametophyte grows in the soil
Let’s zoom in
ground
4) Sperm swim through water from the male parts (antheridium) to the female parts
(archegonia)
Let’s zoom back out
zygo
egg
te
zygo
egg
te
zygo
egg
te
5) Diploid sporophyte grows from the zygote
sporophyte
gametophyte
ground
6) Fronds uncurls into leaves.
7) Cycle repeats
-- Haploid spores created and released
.
.
.
ground
.
Haploid spores land in the soil
ground
From the haploid spores, gametophyte grows in the soil
Let’s zoom in
ground
Sperm swim through water from the male parts (antheridium) to the female parts
(archegonia)
Let’s zoom back out
zygo
egg
te
zygo
egg
te
zygo
egg
te
Diploid sporophyte grows from the zygote
sporophyte
ground
Fronds uncurls into leaves.
Cycle repeats
.
.
.
ground
.
Kobe Kuiz
1) Why do moss grow so low to the ground?
2) Which stage is the main stage of moss: sporophyte
or gametophyte?
3) How do moss reproduce?
4) What is the major difference between moss and
ferns?
5) What are the leaves of ferns called?
6) What is needed for moss and ferns to reproduce?
7) What stage is created when sperm and egg fuse:
sporophyte or gametophyte?
Seeds and their advantages
• 1) Seed plants don’t depend
on water to reproduce
– Pollen (contains sperm)
combines with egg
– Egg hardens into a seed
• 2) Nourishment and
protection
– Nourish: Nutrients inside
seed for the embryo
– Protection: Hard shell
• 3) Allow dispersal
– Carried by wind, water,
animals
Group 3: Seed producing, Vascular Plants
• Type 1: Gymnosperms
• Needle-like leaves (reduces
water loss)
• Common to lumber industry
• Seeds enclosed in protective
cones
– Male cones: produce pollen
– Female cones: produce
eggs
• Zygote hardens into seed after
fertilization
• Ex: Evergreen, Pine,
Redwood, Cedar
Conifer Life Cycle
1) Male and female seed cones grow on adult sporophytes
2) Pollen grains released from the male seed cones
-- Pollen is the male gametophyte
Male cones make pollen
Female cones make eggs
zygo
egg
te
zygo
egg
te
zygo
egg
te
zygo
egg
te
seed
seed
seed
seed
3) Seeds begin to harden inside the female cones
4) Seeds released
5) Seed will land
ground
6) Seedling grows into (sporophyte)…the cycle repeats
ground
1) Male and female seed cones grow in adult sporophytes
Male cones make pollen
Female cones make eggs
zygo
egg
te
zygo
egg
te
zygo
egg
te
zygo
egg
te
seed
seed
seed
seed
3) Seeds begin to harden inside the female cones
4) Seeds released
5) Seed will land
ground
6) Seedling grows into (sporophyte)…the cycle repeats
ground
Kobe Kuiz
1)
2)
3)
4)
5)
Name three advantages of seeds.
Which structure will protect gymnosperm seeds?
What do male cones produce?
What do female cones produce?
What is created when the sperm and egg fuse:
sporophyte or gametophyte?
Group 3: Seed producing, Vascular Plants
• Type 2: Angiosperms
(flowering plants)
• Flower = reproductive
structure
– Attract animals to help
spread pollen
– Forms fruit to protect
fertilized eggs
• Seeds
– Grow inside the fruit
– Inside the seed
1. Embryo
2. Food supply
Seed Disperal
• Fruit brightly colored
– Attracts animals
• Seeds pass through animals
digestive system
• Seeds pooped in a new area
to grow
Fruit seeds in fox droppings
Angiosperm Groups
• 2 groups: Monocots and Dicots (based on seed type)
• Cotyledon: embryonic leaf
• Two Categories:
– Monocots: embryo with 1 seed leaf
– Dicots: embryo with 2 seed leaves
Monocots vs. Dicots
Apple Tree: Monocot or Dicot?
2
3
1
Net-like
veins
4
5
Monocot or Dicot?
Monocot or Dicot?
Monocot or Dicot?
Monocot or Dicot?
Monocot or Dicot?
Monocot or Dicot?
Angiosperm Life Spans
• Three Life Span Types:
1. Annuals
– 1 year: Seed grows…produce
flowers & own seeds…die
2. Biennials
– 1st year: Seed grows and stores
food
– 2nd year: grows more, makes
flowers & seeds…dies
3. Perennials
– Live for more than 2 years
Flowers
• Reproductive structure
of flowering plants
• Sepals
– outer ring of leaves
– protection
• Petals
– Inner ring of leaves
– Brightly colored to
attract pollinators
• Open petals & sepals
reveal male and female
structures
Flowers
• Female Carpel
– Inner most part
– Ovary: within the
base (female
gametophyte)
– Stigma: sticky tip,
collects pollen
• Male Stamen
– Surrounds carpel
– Anther: produces
pollen (male
gametophyte)
Angiosperm Life Cycle
Pollen stick to animal or released
into wind
Animal finds a new flower to feed
on
Pollen transferred to the stigma….seeds develop
zygo
egg
te
Flower petals start to fall off and dies
zygo
te
Fruit falls to ground
Animals eat fruit….seeds come out the other end…cycle repeats
seed
End of the Semester!
Kobe Kuiz
1) What is the reproductive structure of angiosperms
called?
2) What structure protects the seeds of angiosperms?
3) Why are flowers and fruits often brightly colored?
4) Be able to identify the parts of a flower diagram.
5) Which flower part produces pollen?
6) Which flower part will pollen land upon?
7) Which flowers only live for 2 years and then die?
8) Practice the monocot/dicot sample questions.