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Plant Diversity
Origin of Plant Life
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Characteristics of Plants:
o Multicellular
o Eukaryotic
o Cell wall made of cellulose
o Contain chlorophyll- captures energy from sunlight during photosynthesis
o Use starch as a storage product
o Autotrophic
o Immobile (cannot move)
o Multicellular embryos
Plants have adaptions that allow them to live in land
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 Retain Moisture- plants are exposed to air and will dry out
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o Stomata- tiny holes in plant cells that close to prevent water
loss and open to allow air on/out
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Allows plants to grow higher off the ground
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 Reproducing on Land
o Pollen grains allow for reproduction without needing water,
eventually they will become the sperm
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 No roots- absorb water and nutrients directly
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 Require water for reproduction
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Gymnosperms
 Cycads and Conifers (Pine Trees)
 Seed producing vascular plants
 Can reproduce without free standing water using pollen
 Pollen mostly carried by wind
 Pollination- when a pollen grain meets female reproductive parts
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 Seeds are enclosed in a cone
 Different male (pollen) and female (egg) cones
 Cone serves to protect the seeds
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 Have fruit- mature ovary that contains seeds
Advantage of Seeds
 Don’t need water for reproduction
 Seeds nourish and protects plant embryos
 Seeds allow plants to disperse to new places

Diversity of Flowering Plants
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Flowers allow for efficient pollination
o Animals feed on pollen or nectar
o Pollen is spread from plant to plant in the process
Fruit allows for efficient seed dispersal
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o Many forms/functions of seed dispersal
 Fleshy fruits for animals to eat- animals cannot digest seeds
 Shells of sunflower seeds
 Sand burrs or dandelions- aid in dispersal
Flowering plants are classified into two groups based on seed type

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Monocots
 Single seed leaf (one leaf when they first sprout)
 Leaf veins are parallel
 Flower parts in multiples of 3
 Scattered vascular tissue in stem
Dicots
 Two seed leaves
 Leaf veins are net like
 Flowering parts in multiples of four
 Ringed vascular tissue
Also classified based on life span
 Annual- complete life cycle over in one year (corn and most garden flowers)
 Biennial- two years to complete life cycle (carrots)
 Perennial- lives for more than two years (trees)

Plant Cells and Tissues
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Plant tissues are made of thee basic cell types
o Parenchyma- stores starch, oils, and water for plants
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o Collenchyma- Flexible cells that support and give plants structure
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Plant organs are made of thee tissue systems
o Tissues are groups of cells working together to perform a function
o Dermal Tissue- covers the outside of the plant
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 Made of parenchyma cells
o Ground tissue- most of the inside part of a plant
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 Made of parenchyma, collenchyma, and sclerenchyma cells
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 Xylem- vascular tissue that carries water
 Phloem- transports food (products of photosynthesis)

The Vascular System
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Water and dissolved minerals through xylem
o Does not require energy to move water- passive transport
o Cohesion- tension theory- polarity of water allows it to move
 Water molecules stick to each other and the walls of xylem
 Cohesion- water stick to water
 Adhesion- water sticks to other things
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o Moves from a source- where sugars are made to a sink – cells that need sugar
o Made up of live cells
Holes in cell walls of both xylem and phloem allow substances to move through cells

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