PLANTS

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PLANTS
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Characteristics

• Eukaryotic, multicellular, nonmotile
• Photosynthetic- autotroph
• Have chloroplastchlorophyll a and b
• Cell wall made of cellulose- protects and
  supports
• Cuticle- waxy covering that prevents desiccation

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Life Cycle

• 2 alternating cycles
• 2N- diploid sporophyte
• 1N Haploid gametophyte

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Plant Needs

• Sunlight
• Water and minerals
• Gas Exchange
• Movement of water and nutrients

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Plant AdaptationsHow did plants move from water
to land?

1. Vascular tissue xylem carries water from roots,
   phloem carries food made in leaves
2. Cuticleprevents water loss
3. Roots- anchor the plant, absorbs water and
   nutrients
4. Pollen- male sperm- doesnt need water to
   distribute
5. Seeds- provide protection and food supply to
   embryo

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4 MAIN TYPES OF PLANTS
Bryophyte Pterophyte Gymnosperm Angiosperm
Common Name MOSSES FERNS PINES FLOWERING
Vascular tissue No Yes Yes Yes
Male gamete Flagellated sperm Flagellated sperm Pollen Pollen
Dominant Generation Gametophyte Sporophyte Sporophyte Sporophyte
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Mosses

• No vascular tissue and produce flagellated sperm-
  so need to be in close contact with water
• No roots- rhizoids anchor to ground
• Peat moss- used for fuel

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Ferns

• Flagellated sperm
• Has vascular tissue

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Gymnosperm

• Vascular tissue
• Has male and female cones
• Male cone produces pollen
• Female cone produces ovules

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Angiosperm

• Produce flowers
• Produce seeds within a fruit
• Vascular tissue
• Green(Herbaceous) or woody stem

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2 Types of Angiosperms

• Monocot- Grasses, lilies
• Dicot-Shrubs, trees, flowers

• Annuals- live 1 year, have herbaceous or green
  stem(replant)
• Perennial- trees and shrubs
• Biennial- takes 2 years to grow-root storage like
  carrots

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Monocot vs. Dicot
Vascular Bundle in Leaf Vascular Bundle in Stem Cross section Vascular Bundle in Root Cross Section Flower groups
Monocot Parallel Scattered Ring 3s
Dicot Web like Ring X 4s and 5s
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3 Types of Plant Cells

• Parenchyma- storage and food production
• Collenchyma- found in areas of current growth
• Sclerenchyma- thick walled cells used for
  support, also fiber, and grit in pears

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3 Types of Plant Tissues

• Dermal- makes up epidermis-protects- secretes
  cuticle
• Vascular- set of pipes that transport materials
  far distances. Xylem carries water (tracheids and
  vessel elements)
• Phloem carries
  food(sugar)(sieve tube elements and companion
  cells)
• 3. Ground sites of photosynthesis(leaves),
• storage(roots), and support(stems)

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Plant growth

• Meristematic tissue- site of actively dividing
  cells(mitosis). Found at tip of shoot(called
  apical- at the top) and the tip of the root.
• Apical meristem found at the top of the shoot and
  bottom of the root.

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Plant organs

• Roots
• Stems
• Leaves

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Roots

• help anchor plant, absorb nutrients, have root
  hairs to increase surface area
• 2 types- fibrous
• taproot
• (food storage like carrot)
• Monocot
• (vascular
• bundle
• arrangement)
  Dicot

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• Root cap at end of the root- protects new
  ,growing cells. Also produces lubricant so root
  can move
• through soil.

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Stems

• Support the leaves
• 2 types- herbacous- green
• woody
• Monocot (vascular bundle arrangement) Dicot

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Leaf

• Site of photosynthesis

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• Palisade mesophyll and spongy mesophyll-
  photosynthesis cells.
• Spongy mesophyll loosely packed spaces where
  the gases can be stored.
• Vascular bundle contains the xylem and phloem
• Stomata open during times when water loss is
  low(early day or late afternoon)
• Loss of water through stomata called TRANSPIRATION

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• Stomata- opening in the leaf that allows gas
  exchange- O2 out and CO2 in for photosynthesis.
• Guard cells control the opening of the stomata.
  When guard cells fill with water, stomata open.
  When water leaves guard cells- stomata are
  closed.

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Water transport

• What moves water up against gravity?
• Root pressure- movement of water coming up from
  the roots
• Adhesion- water sticks to sides of xylem cells
• Capillary action- water attracted to itself and
  the tube
• Transpiration- when stomata open- help pull the
  water up- negative pressure

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STOMATA
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Flowers

• Reproductive organ of a plant- contains the male
  and female parts
• Plants do not self fertilize- mechanisms in place
  that doesnt allow it.
• Male- stamen (anther and filament)
• Female carpel (stigma, style and ovary)
• Petals- attract pollinator
• Sepal- green leaf surrounding flower

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Plant Hormones

• Auxin- cell elongation
• Gibberellins- promote growth
• Cytokinin- stimulate cell division,growth of
  lateral buds
• Ethylene gas- promotes fruit ripening

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Tropism-

• plant response
• to external stimulus
• like light or gravity
• Thigmotropism- response to touch-vines

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Photoperiodism

• Short Day Plants

• Long Day Plants

• Short day, long night
• Can interrupt night to stop flowering
• Poinsettia

• Long day, short night
• Increase night to stop flowering
• Iris