Major Plant Groups
Jan 18, 2016
Major Plant Groups
Group 1: Seedless, Nonvascular Plants• Live in moist
environments– Need water to
reproduce
• Grow low to ground (nonvascular)
• Lack true leaves
• Common pioneer species
• Gametophyte most common (dominant)
• Ex: Mosses, liverworts, hornworts
Group 2: Seedless, Vascular Plants
• Vascular system– Taller growth– Nutrient transportation
• Live in moist environments– swimming sperm
• Has primitive roots called rhizoids
• Gametophyte stage– Called Prothallus– Creates egg and sperm
• Sporophyte stage– Leaves called “Fronds”– Spores created on underside
in clusters called “sori”
• Ex: Ferns, Club mosses, Horsetails
Fern Frond
Underside of frond
Group 3: Seed producing, Vascular Plants
• Type 1: Gymnosperms
• Needle-like leaves (reduces water loss)
• Common to lumber industry
• Seeds enclosed in cones
– Male cones: produce pollen (sperm)
– Female cones: produce eggs
• Zygote hardens into seed (protected inside cones)
• Ex: Evergreen, Pine, Redwood, Cedar
Gymnosperm Life Cycle
Let’s zoom into the cones of this sporophyte tree.
1) Male and female seed cones grow on adult sporophytes
Male cones Female cone
2) Pollen (male gametophyte) released from the male seed cones.
Female eggs become fertilized
Zygote created inside the female cones
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egg egg
egg
zygote
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zygote
Male cones make pollen Female cones make eggs
3) Seeds begin to harden inside the female cones
seed
seed
seed
seed
4) Seeds often spread by wind
“wing” helps seeds spread greater distance
5) Seed will land
ground
6) Seedling grows into (sporophyte)…the cycle repeats
ground
Seed Advantages• 1) Seed plants don’t
depend on water to reproduce– Pollen spread by wind
and animals• 2) Embryo has….
– Nourishment: Nutrients inside feed embryo
– Protection: Hard shell• 3) Seeds allow for
dispersal– Carried by wind,
water, animals
Some seeds are carried by wind
Some seeds have “wings”
Some seeds are carried by animals
Helicopter seeds
http://www.youtube.com/watch?v=0l3okbzCzFE
Group 4: Flowering Plants
• Angiosperms (flowering plants)
• Flower = reproductive structure– Attract animals to
help spread pollen– Forms fruit to protect
and spread seeds• Seeds
– Grow inside the fruit– Inside the seed
1. Embryo2. Food supply
Seed Dispersal
• Fruit brightly colored
– Attracts animals
• Seeds pass through animals digestive system
• Seeds pooped in a new area to grow
Fruit seeds in fox poop
Angiosperm Groups• 2 groups: Based on
seed type• Cotyledon:
embryonic leaf• Two Categories:
– Monocots: embryo with 1 seed leaf
– Dicots: embryo with 2 seed leaves
Monocots vs. Dicots
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Apple Tree: Monocot or Dicot?
1
2
3
45
Net-like veins
Monocot or Dicot?
1
2
3
4
5
6
Monocot or Dicot?
Monocot or Dicot?
Monocot or Dicot?
Veins run parallel
Monocot or Dicot?
Veins run parallel
Monocot or Dicot?
Veins branch outward
Angiosperm Life Spans
• Three Life Span Types:• 1) Annuals
– Seed grows…
– Produce flowers & 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– May take decades to grow
fruit
sepals
petals• Reproductive
structure of angiosperms
• Sepals– outer ring of leaves– protection
• Petals– Inner ring of leaves – Brightly colored to
attract pollinators• Male and female
organs found inside
Flowers
Tulip Pistil and Stamen
male
female
Lily Pistil and Stamen
male
female
Pistil and Stamen
male
female
Pistil and Stamen
male
female
Flowers• Male Stamen
– Anther: produces pollen (sperm)
• Female Carpel/Pistil– Inner most part– Ovary: within the
base• Contains eggs• Grows into fruit when
fertilized
– Stigma: sticky tip, collects pollen
...
Self-Pollination(own pollen fertilizes own egg)
Cross-Pollination(pollen of one, fertilizes egg of another)
...
Angiosperm Life Cycle
Here is an apple tree….lets zoom into an individual flower.1) Pollen sticks to animal or released into wind
2) Insect flies away covered in pollen
. .... . ...
. ...... ......
Angiosperm Life Cycle1) Pollen sticks to animal or released into wind
2) Insect flies away covered in pollen
3) Insect comes across another flower and spreads the pollen
.. .
... ...
...
Angiosperm Life Cycle1) Pollen sticks to animal or released into wind
2) Insect flies away covered in pollen
3) Insect comes across another flower and spreads the pollen
4) Pollen tube grows towards ovary
.
Angiosperm Life Cycle1) Pollen sticks to animal or released into wind
2) Insect flies away covered in pollen
3) Insect comes across another flower and spreads the pollen
4) Pollen tube grows towards ovary
.
5) Nucleus travels down pollen tube to fertilize egg
.
Angiosperm Life Cycle1) Pollen sticks to animal or released into wind
2) Insect flies away covered in pollen
3) Insect comes across another flower and spreads the pollen
4) Pollen tube grows towards ovary
.
5) Nucleus travels down pollen tube to fertilize egg
.
6) Zygote hardens into seed…flower starts to die
seed
ovary
Angiosperm Life Cycle1) Pollen sticks to animal or released into wind
2) Insect flies away covered in pollen
3) Insect comes across another flower and spreads the pollen
4) Pollen tube grows towards ovary
5) Nucleus travels down pollen tube to fertilize egg
6) Zygote hardens into seed…flower starts to die
7) Ovary grows into a fruit (seeds insides)
ovary
Angiosperm Life Cycle1) Pollen sticks to animal or released into wind
2) Insect flies away covered in pollen
3) Insect comes across another flower and spreads the pollen
4) Pollen tube grows towards ovary
5) Nucleus travels down pollen tube to fertilize egg
6) Zygote hardens into seed…flower starts to die
7) Ovary grows into a fruit (seeds insides)
Angiosperm Life Cycle1) Pollen sticks to animal or released into wind
2) Insect flies away covered in pollen
3) Insect comes across another flower and spreads the pollen
4) Pollen tube grows towards ovary
5) Nucleus travels down pollen tube to fertilize egg
6) Zygote hardens into seed…flower starts to die
7) Ovary grows into a fruit (seeds insides)
seed
A few hours later…
seed
Seedling begins to grow…
Years later….
HW: Bring a flower and leaf to school. One with distinct male and female
parts.