AP Biology Exam Review

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AP Biology Exam Review

• Plant Anatomy and Physiology

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Angiosperm divisions
Dicot 2 cotyledons storage tissue for embryo Netted veins 4X 5X petals Ring of vascular bundles taproot Monocot 1 cotyledon Parallel veins 3X petals Scattered vas. Bundle Fibrous root
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Plant tissue

• Ground tissue parenchyma, collenchyma,
  sclerenchyma
• Dermal tissue lower and upper epidermis, cuticle
• Vascular tissue xylem and phloem

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Vascular tissue

• Xylem primary and secondary cell wall, pits vs.
  perforations, tracheids vs. vessel elements
• Phloem sieve tube members, pores, sieve plants,
  companion cells, plasmodesmata

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Xylem
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Phloem
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Meristems

• Shoot
• Lateral
• Root

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Seed

• Embryo epicotyl (shoot tip), plumule (young
  leaves), hypocotyl (young shoot), radicle (root),
  coleoptile (sheath of monocot)
• Seed coat
• Endosperm or cotyledons
• Remains dormant until ABA washed away

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Seed

• Plumule
• Radicle
• Endosperm
• Seed coat
• Cotyledon
• Hypocotyl dicot
• Coleoptile monocot

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Germination breaking dormancy

• Imbibition absorb water, removing ABA,
  gibberellin promotes germination
• Meristamtic cells actively dividing cells
  (primary growth)
• Root zone of cell division, zone of elongation,
  root cap, zone of maturation

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Seed germination
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Primary vs. secondary growth

• Primary growth primary xylem and phloem (still
  living)
• Secondary growth increases girth (width), occurs
  at vascular cambium and cork cambium, VC ? wood,
  CC ? periderm (cork)

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Root structure

• Epidermis with root hairs
• Cortex
• Endodermis
• Vascular cylinder (stele)

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Root
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Stem structure

• Epidermis with cutin
• Cortex
• Vascular cylinder (xylem, phloem, pith)
• Secondary growth in stems sapwood ? heartwood
  (annual rings)

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Secondary stem growth vascular cambium
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Cell plates plant mitosis
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Tree stem
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Leaf structure

• Epidermis with cuticle
• Palisade mesophyll
• Spongy mesophyll
• Vascular bundle
• Guard cells with stomata

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Leaves
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Transport

• Transpiration water transport
• Bulk flow/source to sink sugar transport

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Transport types

• Plasmodesmata connects two plant cells
• Symplast vs. apoplast

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Water transwport

• Apoplast within cell walls or between cells
• Symplast (within cells, plasmodesmata)
• Requires osmosis, capillary action,
  cohesion-tension

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Root and H2O
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Leaf water potential
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Controlling stomata

• Factors causing stomata to close
• high temperature
• CO2 concentrations low
• Night
• diffusion of K out of guard cells

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Stomata control
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Sugar transport
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Sieve tubepressure flow
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Mineral uptake
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Symbiotic bacteria
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Double fertilization
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Auxin
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Signaling
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Hormoneoverview

• Auxin
• Abscisic acid
• Brassinoid
• Cytokinin
• Ethylene
• Gibberellin