Transcript Vascular Plants

Kingdom Plantae
Botany = study of plants
Botanists = plant biologists
Evolution of Terrestrial Plants
• As plants began to survive on land, they altered the conditions
by slowly creating soil and microclimates.
• Plants provided food for animals that were also evolving
systems to cope with terrestrial life.
Examine your flower
• Record observations about how plants
have evolved to survive on land.
Plant Modifications
• Supportive structures—stems and roots/rhizoids (hair like
roots found in mosses and ferns)
• Transport systems —vascular system (xylem carries water
and materials up from roots, and phloem transports sugar down
from the leaves)
Plant Modifications
• Reduce water loss—cuticle (made of wax)
• Regulate gas exchange & reduce water loss—stomata
• Reproductive strategies—spores, pollen, nectar, and seeds
Characteristics
• Lack mobility
• Their cells are eukaryotic
• Have numerous organelles
• Have cell walls that contain cellulose
• Have the ability to synthesize carbohydrates through the
process of photosynthesis
Divisions of the Kingdom
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Bryophytes
Non-Vascular Plants- Bryophytes
• Mosses form the largest and most familiar group of bryophytes
• Found in moist environments
• They lack a vascular system (no xylem or phloem)
• Mosses depend on simple diffusion, osmosis, and active
transport to move nutrients, wastes, and water to and from their
cells.
Bryophytes
• They are often the first to establish themselves on exposed rock
or soil surfaces where there are no other plants
•As the moss plants die and decompose, they create organic
matter to act as soil and nutrients for other types of plants
•There are at least 1170 species of mosses in North America alone
Examining Moss
• Pg 384
Answers
•
(a) Mosses obtain water from the environment through osmosis.
•
(b) Peat moss increases the water-holding capacity of garden soil.
•
(c) One problem associated with using too much peat moss in garden soil is that many
plants cannot live in an environment with too much water. Also, mosses become acidic as
they decompose.
•
(d) Bogs, composed of peat moss, are responsible for a variety of ecologically beneficial
actions. Bogs filter and collect water, accumulate carbon, and provide a habitat for flora and
fauna. Peat moss is economically beneficial as a commercial garden product, but is also a
renewable source of energy.
Vascular vs Non Vascular
• Colored water with flower vs moss.
• What will happen?
Vascular Plants- Seedless
• Ferns are of the phylum tracheophyte. They are plants with a
vascular system (have xylem and phloem)
• The leafy portion of the fern is called the frond.
• The stems are called rhizomes
• Ferns do not have flowers or seeds. They reproduce as spores
like mosses.
Ferns
Microscope activity
Reproductive Cycle Terms
• Alternation of Generations- The complete life cycle of a plant
• Gametophyte- Stage in which cells have haploid nuclei. Begins
with haploid spores. In ferns the gametophyte plant is called a
prothallus.
• Sporophyte-Stage in which cells have diploid nuclei. Arises
from union of 2 haploid gametes.
• Sporangium- Cell structure in which spores are produced
asexually (in mosses, fungi and ferns)
Alternation of Generations - Fern
Vascular Plants- Seeds- Gymnosperms
• Gymnosperms are plants that produce “naked” seeds (not
enclosed in a fruit), usually inside cones
• Examples include pine trees and spruce trees
• Most have evolved needlelike leaves, which help the plants
resist hot, dry summers, cold winters, and moderate rainfall.
• The needles are covered by a hard, waxy cuticle, which helps
the plant retain moisture.
Gymnosperms
• Gymnosperms have roots that extend over a wide surface area,
rather than penetrating deep into the soil.
• These roots anchor the tree even in locations where soil is
scarce.
Vascular Plants- Seeds- Angiosperms
• Angiosperms are plants that produce seeds enclosed in fruit
formed by certain flower parts
• There are over 250 000 known species of angiosperms (more
species of plants than in all the other plant divisions combined)
• Angiosperms are flowering plants that come in all shapes, sizes,
color, etc….
• No other division of plants has flowers. The flower is the
reproductive centre of the plant.
Perfect and Imperfect Flowers
• Angiosperm that have both male and female reproductive
organs on the same flower is called a perfect flower (wood lily).
• Angiosperms that have separate male and female flowers are
called imperfect flowers (some pumpkin species).
Flower Parts
• Stamen- male part of the flower that consists of a thin stalk
called the filament, and an anther, in which pollen grains are
formed
• Pistil- female part of the flower that consists of three main parts:
stigma, style, and ovary.
• Carpel- One subunit of a more complex ovary
• Sepals- Small, green, leaf like structures that enclose the
developing flower.
• Petals- Often large and colorful
Flower Parts
Hand out blank flower
Flower Dissections
On Cue Cards
• Write down all of the flower parts you
remember.
• Include their functions if you can.
Monocots and Dicots
• Angiosperms are grouped into two classes: monocots, which
have one cotyledon, and dicots, which have two cotyledons
• A cotyledon is a seed leaf that stores carbohydrates for the
young plant and often becomes the first leaf to appear as the
seed germinates.
• Monocot example: Corn
•
Dicot (more common) example: Beans
Monocots and Dicots
Flower Demo
Alternation of Generations- Male Parts
• The filament gets longer and the anther enlarges
•
Each anther has chambers in which diploid microspores are
located.
•
Each of these undergoes meiosis to form haploid microspores
• Each will develop into a mature pollen grain and the anther
chambers split
• The pollen grains will coat the outside of the anthers.
Alternation of Generations- Female parts
• The style gets longer and the stigma enlarges and secretes a
sticky, scented, substance that covers its surface.
• At the bottom of the pistil, the ovary also enlarges.
• Within each ovule, a diploid megaspore undergoes meiosis and
forms four haploid megaspores. Only one survives as the egg.
Alternation of Generations
• Pollination is usually carried out by wind or insects
• The transfer of pollen from the anther to the stigma on the same
plant is called self-pollination
• When pollen is transferred to a flower on a different plant, it is
called cross-pollination
• The pollen grains stick to the stigma. Part of the pollen makes
its way down through the style (via pollen tube) and reaches the
egg in the ovule
Alternation of Generations
• Fertilization  the fusion of microspore and megaspore nuclei
produces the diploid zygote.
Animation
Explain Everything
• Nature walk
• Take photos
• Try to find a plant from each plant
division
• Make explain everything presentation