Structure%20and%20Function%20of%20the%20Flower

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Structure and Function of the Flower

• CXC Biology Syllabus
• Life Processes
• Specific Objectives 9.69.7

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Section A Flower Structure

• Science Objectives
• Students should be able to
• Recognize specified floral parts on most flowers
• Relate each part to its function
• Distinguish between staminate, pistillate/carpella
  te and hermaphrodite flowers
• Core Skills Objectives
• Co-operation/Group work
• Drawing
• CXC Practical Skills
• Drawing

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Structure and Function of the Flower Quiz 1

• What is the male part of the flower called?
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• What is the main function of a flower?
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• What is the function of the carpel?
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• Give one example of a hermaphrodite flower
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• Name the flower structures which protect the
  young flower bud.
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Use the following to label the flower diagram
below Style, stamen, sepal, filament, peduncle,
ovary, anther, receptacle, carpel, stigma, petal,
ovule.
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What is a Flower?

• Plant organ for sexual reproduction
• Flowers produce gametes (sex cells)
• Flowers are necessary for fertilisation to occur

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Flower Diagram
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Parts of the Flower

• Peduncle flower stalk
• Receptacle part of stalk bearing the floral
  organs, at base of flower
• Sepalleaflike structures at flower base,
  protects young flower bud
• Calyx all the sepals together form the calyx
• Petal located inside and above the sepals, often
  large and colourful, sometimes scented, sometimes
  producing nectar
• Stamen male part of the flower, consist of the
  anther and filament, makes pollen grains
• Pollen grains containing the male gametes
• Pistil/Carpel female part of the flower, consist
  of the stigma, style and ovary
• Ovule located in the ovaries, carry female
  gametes
• Staminate flower flower bearing only male parts
• Pistillate/Carpellate flower flower bearing only
  female sex parts
• Hermaphrodite flower flower bearing both male
  and female sex parts

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Method

• Collect specimens of the following flowers (your
  guide will show you where and which flowers to
  collect!)
• Pride of Barbados
• Hibiscus
• Orchid
• Flower of choice
• Make a labeled drawing of the Pride of Barbados
  and Hibiscus flowers (use the flower diagram as a
  guide, include magnification, labels in script)
• Dissect the Pride of Barbados flower ( a
  demonstration will be given)
• Make individual drawings of the petals, sepals,
  stamens, and pistils/carpels
• Dissect the pistil/carpel and make a labeled
  drawing of the ovary and the ovules lying within
  it

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Section BPollination

• Science Objectives
• Students should be able to
• Define pollination
• State the main ways in which plants achieve
  pollination
• Recognize flower adaptations associated with each
  mode of pollination
• Core Skills targeted
• Drawing
• Information Technology
• CXC Practical Skills
• Analysis and Interpretation
• Drawing

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Mode of Pollination

• Insect-pollinated flowers may have
• Brightly coloured petals
• Strong sweet fragrance
• Nectar producing glands
• Guidelines to lead insects to Nectar

• Wind-pollinated flowers may have
• Large stigmas outside the flower
• Little or no fragrance
• Light non-sticky pollen
• Lack showy petals

• Bird-pollinated flowers may have
• Long tube shaped flowers
• Bright red and yellow flowers
• No odour

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Mode of Pollination (Continued)

• Mammal-pollinated flowers may have
• White flowers
• Strong fruity odour
• Flowers opening at night

• Water-pollinated flowers may have
• Pollen which floats on water
• (this form of pollination is rare)

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Method

• Research and define the following terms in the
  Iris Bannochie library and on the Internet
• Pollination
• Self-pollination
• Cross-pollination
• 2. Note the ways in which pollination may occur
• 3. Identify the various adaptations associated
  with each form of pollination
• 4. Collect flower specimens from the gardens and
  determine their method of pollination through
  completion of the Mode of Pollination Table

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Mode of Pollination Table
Flower Name Light non-sticky Pollen Sticky Pollen Colourful Petals Sweet Scented Tube Shaped Mode of Pollination

• denotes a positive response

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Assessment Scheme for Drawing
 
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Use the following to label the flower diagram
below Style, stamen, sepal, filament, peduncle,
ovary, anther, receptacle, carpel, stigma, petal,
ovule.
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Structure and Function of the Flower Quiz 2
Pollination

• Write a short definition for the word
  pollination.
• Why is pollination important to plants?
• State three ways in which pollination can be
  achieved.
• State a plant adaptation associated with each
  mode of pollination above

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Analysis and Interpretation of the Pollination
Exercise

• Background Information/Biological principles.
  (3 marks)
• Relationship to Investigation/Observation.
• State the significance of pollination
  
• Identify the flower structures which play the key
  role in pollination
• Note how these structures are adapted to their
  role
• Explanation/Interpretations of result.
  (3-4 marks)
• Give reasons for interpretation of specified
  result
• Conclusion based on observation/data
• Related to Aim
  (2 marks)
• Correct conclusions drawn
• Limitations
  (1-2marks)
• Limitations of the results/conclusions stated