CHAPTER 24: Plants

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CHAPTER 24 Plants

• High School Biology Class

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Kingdom Plantae

• Members of the Kingdom Plantae dominate the land
  and many bodies of water while exhibiting a
  tremendous amount of diversity.

There are more than 270,000 different plant
species, and new plants continue to be discovered
in the Tropical Rainforests.
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Kingdom Plantae

• 1) Almost all organisms on Earth depend on the
  photosynthetic ability of plants.
• 2) Plants also produce the oxygen you breath, the
  food you eat, and even the paper used to print
  your textbook. 
• 3) Furthermore, plants are a source of many
  medicines that help to keep you healthy. 
• _____________________________________
• Without plants, life as you know it would not
  exist.

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What is a Plant?

• Plant - any of various photosynthetic,
  eukaryotic, multicellular organisms that produce
  embryos, contain chloroplasts, have cellulose in
  their cell walls, and lack movement.

• Mosses, ferns, conifers, cacti, and tulips
• are all different types of plants.

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What is a Plant?

• All plants are photosynthetic.
• All plants are multicellular.
• All plants are eukaryotic.
• All plants can reproduce sexually.
• All plants have cellulose in their cell walls.

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What is a Plant?

• Most plants absorb nutrients by their roots.
• Most plants form mycorrhizae with fungi.
• Most plants prevent water loss by a thick waxy
  coating called a cuticle.
• Most plants use stoma (pores) to let oxygen out
  and carbon dioxide inside of them.

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What is a Plant?

• Some plants are less than 1 mm in width.
• Some plants grow more than 100 m (328 ft) in
  height.
• Some plants complete their life cycles in 1-2
  weeks, while others may live 5,000 years.

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Plant Facts

• In their characteristics, plants are most similar
  to the Green Algae (plant-like protists) that
  live in the water.
• According to the fossil record no organism lived
  on land until about 430 million years ago when a
  layer of ozone formed.
• Scientists hypothesize that fungi and plants were
  the first organisms to invade land.

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Plant History

• Before living on land, plants needed to do 3
  things

1. Absorb nutrients from their surroundings.
and fungi
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Plant History

• Before living on land, plants needed to do 3
  things

2. Prevent their bodies from drying out.
Cuticle
Stoma
Guard Cells
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Specialized Plant Parts

• a. Cuticle - waxy layer that covers the non-woody
  above ground parts of most plants.
• b. Stomata - pores that permit plants to exchange
  oxygen and carbon dioxide.
• c. Guard Cells a pair of specialized cells that
  border each stoma.

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Plant History

• Before living on land, plants needed to do 3
  things
• (Pollen permits the sperm of most plants to be
  carried by wind, water, or animals.)

3. Reproduce without water.
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More Plant History Parts

• Plants became successful on land because
• a. Most plants have a vascular system (vessels or
  ducts) that transport materials through the body.

i. Phloem soft walled cells that move
nutrient/food. ii. Xylem hard walled cells that
move mineral/water.
Xylem
Phloem
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More Plant History Parts

• Plants became successful on land because
• b. Some plants have flowers (reproductive
  structures) that produce pollen or seeds.

i. Pollen encloses sperm and carried by wind,
etc. ii. Seeds protects and contains plant
embryo.
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Plant Seeds
Four advantages of seeds over pollen

• i. Protection
• ii. Delayed Growth
• iii. Dispersal
• iv. Nourishment

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Four Types of Plants

• (The 12 Phlya of Plants)

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1. NONVASCULAR PLANTS

• Lack true roots, stems and leaves.
• Small in size (usually lt 3 cm tall).
• Nutrients and water transported by osmosis and
  diffusion.
• Require water for sexual reproduction.
• Rhizoids - hair-like projections that anchor the
  plant to growing surfaces.

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1. NONVASCULAR PLANTS

• Examples
• Mosses, Liverworts, and Hornworts

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2. SEEDLESS VASCULAR PLANTS

• Have both a phloem and xylem.
• Can grow to large sizes.
• Produce spores (not seeds).
• Have true roots, stems and leaves.
• Rhizomes - horizontal underground stems.

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2. SEEDLESS VASCULAR PLANTS
Have Distinctive Body Forms

• a. Shoot - part of a plants body that grows
  mostly upward.
• b. Root - part of a plants body that grows
  mostly downward.
• c. Meristems - zones of actively dividing plant
  cells that produce plant growth.

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MERISTEM
SHOOT
MERISTEM
ROOT
MERISTEM
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2. SEEDLESS VASCULAR PLANTS

• Examples
• Ferns, Club Mosses, Horsetails, Whisk Ferns

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Vascular Plants

• These are currently the most complex organisms of
  the plant kingdom.
• Can be separated into two subtypes

i. Gymnosperms ii. Angiosperms
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3. GYMNOSPERMS

• Naked Seeds
• Plants whose seeds do not develop within a sealed
  container (fruit).
• Seeds
• Male and female cones
• Wind pollination
• Water pollination
• Animal pollination

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3. GYMNOSPERMS

• Examples
• i. Conifers (redwood, pine, spruce, etc.)
• ii. Cycads
• iii. Ginkgo (male and female separate trees)
• iv. Gnetophytes

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4. ANGIOSPERMS

• Seed Cases
• Plants which produce seeds that develop while
  enclosed within a specialized structure (fruit).
• Most successful of all the plant groups.
• Flowers promote pollination and fertilization.

Seed Cases (Fruit)
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Angiosperm Parts

• a. Flowers - reproductive structures that produce
  pollen and seeds.
• b. Fruits - structure in which seeds of
  angiosperms develop and are used for seed
  dispersal.
• c. Endosperm - supply of stored food inside of
  seeds.

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Angiosperm Types

• Angiosperms can be divided into two
  sub-categories of plants as well
• i. Monocots
• ii. Dicots

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Angiosperm Types

• Monocots - flowering plants that produce seeds
  with one seed leaf.
• - Usually produce flower parts in multiples of
  three and have long narrow leaves with parallel
  veins.

- Examples Irises, Tulips, Wheat, Corn, Rice,
Grass
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Angiosperm Types

• Dicots - flowering plants that produce seeds with
  two seed leaves.
• - Usually produce flower parts in twos, fours,
  or fives and have branching or netted veins.

• - Examples
• Daises, Sunflowers, Lettuce, Beans, Peas,
• Apples, Roses, Tomatoes, Peanuts

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Plants Are Beneficial

• 1. Many Plants are valuable food sources for
  humans.
• - Fruits (contains seeds)
• - Vegetables (non-reproductive parts)

Examples apples, bananas, melons
Examples broccoli, lettuce, cabbage
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Plants Are Beneficial

• 2. Many Plant parts are important foods.
• - Root Crops (provide starch)
• - Legumes (provide protein)

Examples potatoes, yams, carrots
Examples peas, beans, alfalfa
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Plants Are Beneficial

• 3. Plants are used in many food products
• - Wheat
• - Corn
• - Rice

Examples breads, pastas, flour, cereal
Examples grits, corn oil, margarine, starch
Examples brown, white, baby food
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Plants Are Beneficial

• 4. Plants have nonfood related uses as well.

- Rubber (latex) - Fuel-grade Ethanol
(gasoline) - Fibers (clothing, rope, paper) -
Wood (paper, heating/cooking, building homes)
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Plants Are Beneficial

• 5. Plants are used as medicines.
• Examples

a. Caffeine (tea leaves act as a stimulant) b.
Codeine (poppy fruits relieve pain) c. Cortisone
(yam tubers relieve allergies) d. Ephedrine
(stems act as decongestant) e. Taxol (tree bark
reduces cancer tumors)
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Any Questions?

• Embrace hard things and your mind will
  blossom. --Japanese proverb
• Great oaks from little acorns grow.
• --Latin proverb