Presentation is loading. Please wait.

Presentation is loading. Please wait.

FLOWERS AS REPRODUCTIVE STRUCTURES

Similar presentations


Presentation on theme: "FLOWERS AS REPRODUCTIVE STRUCTURES"— Presentation transcript:

1 FLOWERS AS REPRODUCTIVE STRUCTURES
ABBOTTS PAGE 53

2 FLOWER STRUCTURE PAGE 53

3 Parts of a Flower Stigma Style Ovary Carpel/Pistil (female)
Stamen (male) Anther Filament petals ovule sepal DIAGRAM PAGE 53

4 Peduncle: flower stalk
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

5 FLOWER ANATOMY Anther Stigma Filament Pollen Tube Style Ovary Stamen
Ovule Petal Sepal Carpel

6

7 PURPOSE OF EACH FLOWER PART
A. Carpel: Stigma- Covered in a sticky substance that pollen grains can stick to Style- Raises the stigma away from the ovary to decrease pollen contamination Ovary- Protects the ovule after fertilization; becomes the fruit Pollen Tube- What the pollen travels through to reach the eggs in the ovule Ovule- Like the egg in animals; once fertilization takes place it will become the seed.

8 PURPOSE OF EACH FLOWER PART
B. Stamen: Anther- Contain pollen sacs. The sacs release pollen on to the outside of the anthers where wind or other organisms can transfer the pollen to the carpel for fertilization. Filament- Stalk of the anther C. Petal: Petals are used to attract insects into the flower, they may have guidelines on them and be scented. D. Sepal: Sepals protect the flower whilst the flower is developing from a bud.

9 FLOWER FUNCTIONS Flowers contain the reproductive organs
PAGE 54 Flowers contain the reproductive organs Stamens – male parts Carpel – female part Flowers attract pollinators who transport pollen from the anther to the stigma

10 DRAW FLOWER IN YOUR WORKBOOK
TO DO DRAW FLOWER IN YOUR WORKBOOK PAGE 53

11 DRAWING Use a sharp HB pencil
Drawing must be big enough e.g. Half a page Leave enough space around the drawing for labels Labels must be written in ink and not cover the diagram itself Label lines must be in ink, drawn with a ruler and must not cross each other The line must not end with an arrow and it must indicate the exact part that is being labelled The drawing should have a heading stating what the diagram shows

12 POLLINATION BY POLLINATORS
ADD TO WORKBOOK Pollinators are organisms that aid in the transfer of pollen from anther to stigma, to allow for fertilization Flowers get pollinated and pollinators get food Pollination takes place through: insects wind birds water

13 POLLINATION PAGE 54 Is the transfer of ripe pollen containing the male gametes from the anthers to the stigma to allow for fertilization

14 Self Pollination = when the pollen from one flower is used to fertilize the eggs produced by that same flower; true-bred flowers

15 Cross Pollination = when the pollen from one flower is used to fertilize a different flower of the same type

16 POLLINATION BY POLLINATORS
Pollinators are animals that move pollen from anther to stigma, to allow for fertilisation Pollinators visit flowers to get food (pollen and nectar) Flowers get pollinated and pollinators get food Pollinators are mostly insects (some are vertebrates) PAGE 55

17 ADAPTATIONS OF INSECT-POLLINATED FLOWERS
PAGE 55 The flowers have large conspicuous petals in bright colours Sweet scent to attract moths and butterflies Offer a reward of nectar and/pollen Anthers and stigma are often inside the flower Pollen grains are often sticky or spiky (stick to the insects Large quantities of pollen are produced Flowers have nectar guides to help the insect find the centre of the flower

18 SOUTH AFRICAN INSECT-POLLINATED FLOWER
PAGE 56 Bluish in colour – bees pollinate blue and yellow flowers Delicate sweet scent Sturdy with a landing platform on which the bee lands Have nectaries which secrete nectar (sweet liquid) to attract and feed pollinators Flowers are open in the daytime Pollen grains stick to the bodies of bees Salvia africana-caerulea

19 ADAPTATIONS OF BIRD POLLINATED FLOWERS
PAGE 56 Flowers produce a large quantity of dilute nectar Flowers are bigger than insect pollinated flowers Flowers are red and open in the daytime Flowers are sturdy – birds are rough Flowers have little or no scent – birds have a poor sense of smell Ovules are protected from the probing beaks Pollen grains stick together in clumps – bird picks up a lot of pollen in one visit Flowers are erect with a landing platform

20 SOUTH AFRICAN BIRD-POLLINATED FLOWER
PAGE 57 Flowers stand at the tips of long stalks Flowers have a sturdy landing place for sunbirds Flowers have three orange sepals and three blue petals Two of the petals join together to form a dart to hold the stamens, style and nectary Dart provides a perch for the sunbird strelitzia reginae

21 The structure and pollination of the flowers is fascinating.
The hard, beak-like sheath from which the flower emerges, is called the spathe. This is held at right angles to the stem, and has the appearance of a bird's head. Each spathe contains 4 to 6 flowers, and these emerge one at a time from the spathe. Each flower consists of 3 clear yellow sepals and 3 deep purple petals. The yellow sepals give the appearance of a crest on the 'bird's' head. Two of the purple petals are joined together around the stamens and the style to form an arrow-like structure. The third purple petal is visible as a small scale. EXTRA STUFF DART FORMED BY BLUE PETALS SEPALS SPATHE

22 ADAPATATIONS OF A WIND-POLLINATED FLOWER
Page 57 Small, inconspicuous flowers without any bright petals Petals are often absent for better exposure to wind No nectar or produced No scent Male flowers are often arranged in catkins (clusters) that move freely in the wind Long thin filaments hang outside the flower, easily shaken by the wind Anthers are large and well exposed to catch the wind Pollen grains are small (non sticky) and light and easily carried by the wind Stigmas are long and feather- like with a large surface area and outside the flower to trap pollen

23 Examples of inflorescence types.
WORKBOOK An inflorescence is a group or cluster of flowers arranged on a stem

24 SOUTH AFRICAN WIND POLLINATED FLOWER
PAGE 58 SOUTH AFRICAN WIND POLLINATED FLOWER Simple flowers with all the features of wind pollinated flowers except the anthers are not visible Thamnochortus pellucidus in flower

25 Female inflorescence  Male inflorescence Wind distributes the pollen to the female infloresence – caught by bracts and directed to hidden female flowers The male infloresence hangs down on a flexible stalk to shake the pollen free

26 DIFFERENCES BETWEEN BIRD AND INSECT POLLINATED FLOWERS
Shape of flower Corolla tube wide and often horizontal – suits approach flight of insects Landing platform present Corolla tube often long and narrow to suit shape of birds beak No landing platform Colour Not red- bee deterrent Often red – bird attraction colour Corolla Not large or strong Larger and stronger Nectar Less nectar- stronger concentration Much dilute nectar Nectar guides Present – insect vision not good Absent – bird has excellent vision Scent yes Never Night blooming Sometimes – moths pollinate at night never PAGE 58

27 SIMILARITIES BETWEEN BIRD AND INSECT POLLINATED FLOWERS
PAGE 59 Produce less pollen than wind pollinated flowers; there is no wastage as the pollen is taken directly between plants Both produce nectar Have pollen grains with spikes etc so that they stick together and can attach easily to the pollinator Have stigmas and anthers either just outside or inside the flower Might be affected by disease organisms that are carried to the flower along with pollen Have obvious petals

28 Pollinator eg bird/insect
DIFFERENCES BETWEEN POLLINATOR AND WIND POLLINATION PAGE 59 Feature Pollinator eg bird/insect Wind Shape of flower Conspicuous inconspicuous Flower Obvious Usually quite large, coloured scented petals Stigma Often inside the flower Large feathery stigmas, outside Stamens Large stamens, always hang outside Pollen Fewer pollen grains, which have spikes to stick together in clumps A lot of small,dry light pollen grains Pollination process Not wasteful Random and wasteful Disease transfer Disease organisms can be transferred with the pollen No disease transfer Energy expenditure Great – used for pollination, formation of nectar, etc Less, only used to produce pollen Scent and nectar Can be present No scent or nectar

29 TO DO TEXTBOOK PAGE 61 LEARNING ACTIVITY 18
ADAPTATIONS OF FLOWERS FOR POLLINATION

30 FERTILISATION DIAGRAM PAGE 62
Fertilisation is the combining of nuclei of a male and female gamete to form a zygote

31

32

33 POLLINATION PAGE 54 Is the transfer of ripe pollen containing the male gametes from the anthers to the stigma to allow for fertilization

34 WHAT HAPPENS AFTER FERTILISATION?
The zygote forms an embryo inside the ovule The rest of the ovule forms endosperm (food for the germinating seed) The outer layer of the ovule forms the testa (hard, dry, protective layer) The mature ovule = seed

35 WHAT HAPPENS AFTER FERTILISATION?
The ovary grows and encloses and protects the seeds =fruit

36

37 TO DO TEXTBOOK PAGE 62 LEARNING ACTIVITY 19
POLLINATION AND FERTILISATION

38 THE END


Download ppt "FLOWERS AS REPRODUCTIVE STRUCTURES"

Similar presentations


Ads by Google