1. Sexual Reproduction in Flowering Plants
b) Pollination & Fertilisation

2. Learning objectives Define the terms: pollination, self-pollination
Outline methods of pollination including: cross-pollination & self pollination
Define the term: fertilisation.
Outline seed structure & function of following: testa, plumule, radicle, embryo, cotyledon
Explain embryo & food supply (endosperm or seed leaves)
Classify plants as monocotyledon or dicotyledon & distinguish between them.
Make reference to non-endospermic seed.

3. Sexual reproduction in flowers

4. Can you answer the following from your JC Science
Pollination involves the transfer of pollen from the _______________ to the __________________
Self-pollination: _________________________
Cross-pollination: ___________________________
Put these stages of sexual reproduction in order
(a) Germination
(b) Seed and fruit formation
(c) Pollination
(d) Seed dispersal
(e) Fertilisation

6. Answer the questions on the following video
What method is used to transfer pollen in daffodils?
Insect
What type of pollination occurs in daffodils?
Cross
Name 1 feature found in flowers involved in insect pollination
Landing strips to guide insects into flower, nectar, colourful petals
Describe the appearance of the pollen of flowers involved in wind pollination
Smooth, produced in large amounts
What happens in some flowers if cross pollination doesn’t occurs
Self pollination
How do plants prevent self fertilisation
Release chemicals that favours pollen from other plants
How do imperfect flowers prevent fertilisation
Male and female parts are out of sync

7. Pollination

8. Pollination
Transfer of pollen from the anther to the stigma of a flower of the same species

9. Pollination
Pollination

10. Pollination Cross pollination Self pollination
Transfer of pollen from the anther to the stigma of a different plant of the same species to form zygotes. Most common. Cross pollination increases variation.
Self pollination
Transfer of pollen from an anther to a stigma of the same plant to form zygotes

11. Methods of pollination
Insect Pollination
Wind Pollination

13. Pollination by Insects
What do flowers, that are involved in insect pollination look like?
Petals: Large & coloured
Scented
Nectaries to produce nectar
Anthers and Stigmas inside the flower
Pollen: Spikey
E.g. : tulip, buttercup

14. Adaptations for wind pollination

15. Pollination by Wind
What do flowers, that are involved in wind pollination look like?
Petals: small and green
No scent
No nectaries or nectar
Anthers and feathery stigmas hanging outside the flower
Pollen: Large amounts & smooth
E.g.: grass, oak

16. Learning Check What is pollination
Name 2 types of pollination and explain each
Name 2 methods of pollination
For each method, explain the appearance of the flower.

17. Fertilisation

18. Fertilisation
Fertilisation is the fusion of the nuclei of the male (n) and female (n) gametes to produce a zygote (2n)

19. Fertilisation The pollen grain produces the male gametes
Embryo sac produces an egg cell and 2 polar nuclei
Embryo sac
Polar nuclei
Egg cell

20. Stigma
Style
Ovary

21. Embryo Sac
Polar nuclei
Egg Cell

22. Pollen Grain

23. Pollen Tube

24. Generative Nucleus
Tube Nucleus

26. Mitotic division of generative nucleus to form 2 male gametes
Tube nucleus disintegrates

28. One Male gamete fuses with the two polar nuclei to form the triploid endosperm nucleus
One male gamete fuses with the egg nucleus to form the diploid zygote

29. 3n Endosperm nucleus
Double fertilisation
2n Zygote

30. Learning Check What is fertilisation
Name the 2 types of nuclei in the ovule that are involved in fertilisation
Explain the method of fertilisation in 3 steps
What is double fertilisation

31. Sexual Reproduction in Flowering Plants
c) Seed Formation

32. Endospermic & Non-Endospermic Monocots & Dicots
Seed formation
Endospermic & Non-Endospermic
Monocots & Dicots

33. Seed Formation: A seed develops from a fertilised ovule
3n Endosperm nucleus
2n Zygote
The zygote grows repeatedly by mitosis to form an embryo
Embryo: (part of seed that) becomes the new plant
An embryo consists of a
plumule (shoot)
a radical (root)
cotyledons (food stores needed for germination)

34. Seed Formation
The endosperm nucleus (3N) divides repeatedly to form the endosperm in endospermic seeds. This endosperm acts as a food store for the developing seed
e.g. maize
3n Endosperm nucleus
2n Zygote

35. Seed Formation
In non-endospermic seeds the endosperm is used up in the early stages of seed development so the food is stored in the cotyledons
e.g. broad bean
3n Endosperm nucleus
2n Zygote

36. Seed Formation Endosperm Food store for developing embryo
Embryo Plumule, radicle, cotyledons
Integuments, becomes the seed coat

37. Seed Formation
If all the endosperm is absorbed by the developing embryo the seed is a non-endospermic seed e.g. broad bean

38. Seed Formation
If all the endosperm is not absorbed by the developing embryo the seed is an endospermic seed e.g. Maize

39. Cotyledon:. - Seed leaf specialised for food storage
Cotyledon: - Seed leaf specialised for food storage. - Stores food such as starch and sugar Testa: - Seed coat.

40. Seed types and structure
embryo
Plumule (immature shoot)
Radicle (immature root)
Cotyledon (food supply or seed leaf)
endosperm
Food store
All seeds
In some seeds

41. Endospermic Seed e.g. Maize
Seed coat (testa)
Cotyledon
Endosperm
Plumule – will develop into a new shoot
Radicle – will develop into a new root

42. Endospermic seed: contains endosperm when fully developed
Moncotyledons (one cotyledon)
Small, food is stored in the endosperm
Cotyledon absorbs food from endosperm and passes it onto embryo
E.g. Maize

43. Non-Endospermic seed e.g. Broad Bean
Seed coat (testa)
Cotyledon
Plumule
Radicle

44. Non-endospermic seed: Has no endosperm when fully formed
Dicotyledons (2 cotyledons)
Food is stored in the cotyledons
No longer has endosperm as it is used up
E.g. broad beans

45. Non–endospermic and Endospermic seed
Cotyledon
Plumule
Radicle
e.g. Broad Bean
e.g. Maize

46. Classification of seeds
Classified according to two features:
Number of cotyledons (Seed leaves)
Monocotyledon
Dicotyledon
Presence of endosperm
Present – Endospermic
Absent – Non-endospermic

47. Broad Bean – Non-Endospermic Dicot
Testa
2 Cotyledons

48. Grass Barley Daisy Rose Stems are herbaceous Stems can be herbaceous
or woody

49. Example of Monocot and Dicot
Buttercup
Grass

52. Learning Check
What method of division occurs in a zygote to form the embryo
Name the 3 parts of the embryo
What 2 ways are seeds classified
Explain endospermic and non-endospermic
Give an example of each of the above
Name 3 features of a monocot and 3 features of a dicot
State 2 places food is stored in a seed?

53. Can you……. Define the terms: pollination, self-pollination
Outline methods of pollination including: cross-pollination & self pollination
Define the term: fertilisation.
Outline seed structure & function of following: testa, plumule, radicle, embryo, cotyledon
Explain embryo & food supply (endosperm or seed leaves)
Classify plants as monocotyledon or dicotyledon & distinguish between them.
Make reference to non-endospermic seed.