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

Structure and Function of the Flower Biology

Life Processes

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

What is a Flower?

• Plant organ for

sexual reproduction

• Flowers produce

gametes

(sex cells) • Flowers are necessary for

fertilisation

to occur

Flower Diagram

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

• • • • • • • •

1.

2.

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 • • •

3.

Bird-pollinated flowers

may have: Long tube shaped flowers Bright red and yellow flowers No odour

Mode of Pollination (Continued) • • • 4.

Mammal-pollinated flowers may have: White flowers Strong fruity odour Flowers opening at night • 5.

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

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. ------------------------------------------------------------------------------------------

Method

1.

Collect specimens of two different flowers Make a labeled drawing of the individual flowers (use the flower diagram as a guide, include magnification, labels in script) 2.

Dissect a flower ( a demonstration will be given) 3.

4.

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

Let’s elaborate

1. Collect/ find two flower specimens.

2. Draw the first specimen in detail, making sure to draw each part of the organism.

3. Label each part of the organism that is visible without taking apart the flower.

4. Write a sentence using a sentence frame about each of the parts.

Let’s elaborate

5.After you have labeled each part, dissect (or take apart by hand) the flower to locate the inner parts.

6. Label each inner part of the flower organism.

7. Write a sentence using a sentence frame about each inner part.

Element Clarity Accuracy Labeling/ Labeling lines Labels accurate Acceptable title Magnification Total

Assessment Scheme for Drawing

Criteria

Clean continuous lines of even thickness No shading or unnecessary detail Reasonable size

Sub-Total

Any 3=2 Any 2=1 Faithfulness of reproduction Structures typical of specimen included Reasonable proportions Neat drawn with a ruler; in pencil; not crossing No arrowheads; touching labeled structure Labels in script 1 1 1 1 1

Total

2 marks 3 marks 2 marks 1 mark Accurate description of specimen In caps Below drawing Any 2=1 1 mark 1 mark

10 marks

1.

Structure and Function of the Flower Quiz #2 Pollination 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

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