Botany: the study of plants Botanical: of or relating to plants

Botanical Adaptations

Introduction1. What is an adaptation?Characteristic that helps organism survive and reproduce

2. Why adapt? Increase reproductive fitness (# of successful offspring)

3. How adapt?Evolution: �Collective changes in a population as a result of:

•  variation in a population (often caused by mutation),•  selection for or against of certain individuals in the

population based on their characteristics•  reproduction passing on the selected characteristic that

allowed for survival

Example of Plant Evolution•  Variation:Flowers originated as modified/ adapted leaf structures

•  Selection: Plants with flowers attracted more pollinators

•  Reproduction: Plants with flowers produced more offspringPlants with flowers became more �abundant

Adaptations of Flowering PlantsAdaptation/Structure Function

Seed contains nutrients energy and plant parts required for early growth

Monocot vs. DicotAdaptation/Structure Monocot Dicot

Seed •  one cotyledon•  endosperm

•  two cotyledons•  hypocotyl present

A epicotyl

B radicle

C cotyledon

D seed coat

Seeds

A

BC

D

Adaptations of Flowering PlantsAdaptation/Structure Function

Seed contains nutrients energy and plant parts required for early growth

Fruit contain seeds and assist in dispersal

Fruits

Adaptations of Flowering PlantsAdaptation/Structure Function

Seed contains nutrients energy and plant parts required for early growth

Fruit contain seeds and assist in dispersal

Flower•  sexually reproductive structures

•  allows recombination of gametes (pollen and ovule) to create seeds/fruits and increase variation.

Monocot vs. DicotAdaptation/Structure Monocot Dicot

Seed •  one cotyledon•  endosperm

•  two cotyledons•  hypocotyl present

Flower •  parts in multiples of three (usually)

•  parts in multiples of four or five (usually)

Flowers

Adaptations of Flowering PlantsAdaptation/Structure Function

Seed contains nutrients energy and plant parts required for early growth

Fruit contain seeds and assist in dispersal

Flower•  sexually reproductive structures

•  allows recombination of gametes (pollen and ovule) to create seeds/fruits and increase variation.

Stems•  contains vascular system (tissues) for water and food transport•  xylem – takes water up through plant (like veins)•  phloem – takes food down through plant (like arteries)

Monocot vs. DicotAdaptation/Structure Monocot Dicot

Seed •  one cotyledon•  endosperm

•  two cotyledons•  hypocotyl present

Flower •  parts in multiples of three (usually)

•  parts in multiples of four or five (usually)

Stems•  xylem and phloem in separate

bundles•  scattered

•  xylem and phloem organized in layers

•  rings

Stems

Adaptations of Flowering PlantsAdaptation/Structure Function

Seed contains nutrients energy and plant parts required for early growth

Fruit contain seeds and assist in dispersal

Flower•  sexually reproductive structures

•  allows recombination of gametes (pollen and ovule) to create seeds/fruits and increase variation.

Stems•  contains vascular system (tissues) for water and food transport•  xylem – takes water up through plant (like veins)•  phloem – takes food down through plant (like arteries)

Leaves photosynthesis and gas exchange

Monocot vs. DicotAdaptation/Structure Monocot Dicot

Seed •  one cotyledon•  endosperm

•  two cotyledons•  hypocotyl present

Flower •  parts in multiples of three (usually)

•  parts in multiples of four or five (usually)

Stems•  xylem and phloem in separate

bundles•  scattered

•  xylem and phloem organized in layers

•  rings

Leaves

•  vascular tissue (xylem and phloem) bundled together

•  parallel vein arrangement•  narrow

•  vascular tissue in layers•  networked vein arrangement•  broad

Leaves

Leaves

Adaptations of Flowering PlantsAdaptation/Structure Function

Seed contains nutrients energy and plant parts required for early growth

Fruit contain seeds and assist in dispersal

Flower•  sexually reproductive structures

•  allows recombination of gametes (pollen and ovule) to create seeds/fruits and increase variation.

Stems•  contains vascular system (tissues) for water and food transport•  xylem – takes water up through plant (like veins)•  phloem – takes food down through plant (like arteries)

Leaves photosynthesis and gas exchange

Roots absorb water and nutrients

Roots

Monocot vs. DicotAdaptation/Structure Monocot Dicot

Seed •  one cotyledon•  endosperm

•  two cotyledons•  hypocotyl present

Flower •  parts in multiples of three (usually)

•  parts in multiples of four or five (usually)

Stems•  xylem and phloem in separate

bundles•  scattered

•  xylem and phloem organized in layers

•  rings

Leaves

•  vascular tissue (xylem and phloem) bundled together

•  parallel vein arrangement•  narrow

•  vascular tissue in layers•  networked vein arrangement•  broad

Roots

•  xylem and phloem arranged in layers/rings (different from their stems)

•  fibrous roots

•  xylem and phloem organized in layers/rings (similar to their stems)

•  tap root

Adaptations of Flowering PlantsAdaptation/Structure Function

Modified Structures•  food storage reserves•  swollen leaves, stems or roots adapted for interrupted life•  stores supply of water, sugars/starches and proteins

Photosynthetic AdaptationsPlant photosynthesis:•  source of energy sustaining 99% of all life on earth•  conversion of light energy into chemical energy�

(6CO2 + 6H2O + light => C6H12O6 + 6O2)•  occurs in two sets of

reactions:�- light-dependent�- light-independent

Plants vary in how they undergo the light-independentreactions of photosynthesis

Photosynthetic AdaptationsOutcomes:�•  Describe environmental pressures under which different

adaptations for photosynthesis evolved.�

•  Compare and contrast adaptations C3, C4 and CAM plants have evolved to photosynthesize in different environmental conditions.�

•  Construct an argument for an investigation exploring the effect of various environmental conditions on photosynthesis of C3, C4 and CAM plants.

Photosynthetic AdaptationsMethod

What Plants have this Adaptation

Location in Leaf Where Reaction Occurs

Enzyme Responsible for Reaction

When is it Best Fit

C3most plants (dicots)

mesophyll cells – �mid-leaf cells

rubisco - requires high amounts of CO2 to be efficient

•  in moderate temperatures, with adequate water

•  plants can keep stomata open to take in more CO2 without losing too much H2O

C4most monocots

bundle sheath cells - surround vascular tissue

PEP – does not require high amounts of CO2 to be efficient

•  in high temperatures and dry conditions

•  plants can close stomata to avoid H2O loss and still utilize low concentrations of CO2

CAMsucculents and some tropical

mesophyll cells –�at different times – day and night)

PEP

•  in extremely dry conditions•  plants keep stomata closed in day

to avoid H2O loss•  plants open stomata at night, CO2

stored for use during the day

Leaf Cross-sections of C3 and C4 Plants: