Andromeda Botanic Gardens Educational Series: #2

Structure and Function of the Flower

CXC Biology SyllabusLife Processes

Specific Objectives 9.6&9.7

Andromeda Botanic Gardens Educational Series: #2

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/carpellate and hermaphrodite flowers

Core Skills Objectives:• Co-operation/Group work

• Drawing

CXC Practical Skills

• Drawing

Andromeda Botanic Gardens Educational Series: #2

Structure and Function of the Flower Quiz #1

1. What is the male part of the flower called?------------------------------------------------------------------------------------------

2. What is the main function of a flower?------------------------------------------------------------------------------------------

3. What is the function of the carpel?------------------------------------------------------------------------------------------

4. Give one example of a hermaphrodite flower------------------------------------------------------------------------------------------

5. Name the flower structures which protect the young flower bud. ------------------------------------------------------------------------------------------

Andromeda Botanic Gardens Educational Series: #2

Use the following to label the flower diagram below:Style, stamen, sepal, filament, peduncle, ovary, anther, receptacle, carpel, stigma, petal, ovule.

Andromeda Botanic Gardens Educational Series: #2

What is a Flower?

• Plant organ for sexual reproduction

• Flowers produce gametes (sex cells)

• Flowers are necessary for fertilisation to occur

Andromeda Botanic Gardens Educational Series: #2

Flower Diagram

Andromeda Botanic Gardens Educational Series: #2

Parts of the Flower• Peduncle: flower stalk

• Receptacle: part of stalk bearing the floral organs, at base of flower

• Sepal:leaflike 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

Andromeda Botanic Gardens Educational Series: #2

Method1. Collect specimens of the following flowers (your guide will

show you where and which flowers to collect!)• Pride of Barbados• Hibiscus • Orchid• Flower of choice2. Make a labeled drawing of the Pride of Barbados and Hibiscus

flowers (use the flower diagram as a guide, include magnification, labels in script)

3. Dissect the Pride of Barbados flower ( a demonstration will be given)

4. Make individual drawings of the petals, sepals, stamens, and pistils/carpels

5. Dissect the pistil/carpel and make a labeled drawing of the ovary and the ovules lying within it

Andromeda Botanic Gardens Educational Series: #2

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 pollinationCore Skills targeted• Drawing• Information TechnologyCXC Practical Skills• Analysis and Interpretation• Drawing

Andromeda Botanic Gardens Educational Series: #2

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

Mode of Pollination

3. Bird-pollinated flowers may have:

• Long tube shaped flowers

• Bright red and yellow flowers

• No odour

2. Wind-pollinated flowers may have:

• Large stigmas outside the flower

• Little or no fragrance

• Light non-sticky pollen

• Lack showy petals

Andromeda Botanic Gardens Educational Series: #2

Mode of Pollination (Continued)

5. Water-pollinated flowers may have:

• Pollen which floats on water

(this form of pollination is rare)

4. Mammal-pollinated flowers may have:

• White flowers

• Strong fruity odour

• Flowers opening at night

Andromeda Botanic Gardens Educational Series: #2

Method1. 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

Andromeda Botanic Gardens Educational Series: #2

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

Andromeda Botanic Gardens Educational Series: #2

Assessment Scheme for Drawing

Element Criteria Sub-Total Total

Clarity Clean continuous lines of even thickness Any 3=2  

  No shading or unnecessary detail   2 marks

  Reasonable size Any 2=1  

       

Accuracy Faithfulness of reproduction 1  

  Structures typical of specimen included 1 3 marks

  Reasonable proportions 1  

       

Labeling/Labeling lines

Neat drawn with a ruler; in pencil; not crossingNo arrowheads; touching labeled structure

1  

  Labels in script 1 2 marks

       

Labels accurate     1 mark

       

Acceptable title Accurate description of specimen    

  In caps Any 2=1 1 mark

  Below drawing    

       

Magnification     1 mark

       

Total     10 marks

Andromeda Botanic Gardens Educational Series: #2

Use the following to label the flower diagram below:Style, stamen, sepal, filament, peduncle, ovary, anther, receptacle, carpel, stigma, petal, ovule.

Andromeda Botanic Gardens Educational Series: #2

Structure and Function of the Flower Quiz #2 Pollination 1. Write a short definition for the word pollination.

2. Why is pollination important to plants?

3. State three ways in which pollination can be achieved.

4. State a plant adaptation associated with each mode of pollination above

Andromeda Botanic Gardens Educational Series: #2

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/dataRelated to Aim (2 marks)• Correct conclusions drawn Limitations (1-2marks)• Limitations of the results/conclusions stated