1. Insect-pollinated flowers
Often yellow or blue
Have a scent
Bird-pollinated flowers
Often yellow, orange, or red
Do not have a strong scent

2. Ultraviolet markings on insect-pollinated flowers

3. Bat-pollinated flowers
Often have dusky white petals
Are scented
Wind-pollinated flowers
Often have smaller petals or none at all
Have neither scent nor nectar
Make large amounts of pollen

4. Animal pollinators: Archilochus colubris obtains nectar

5. Animal pollinators: Leptonycteris curasoae obtains nectar

6. Wind pollination

7. Coevolution Reciprocal adaptation Caused by two species
Forming interdependent relationship
Affecting the course of each other’s evolution
E.g., certain showy flowers + bees

8. Pollination Fertilization
Transfer of pollen grains from anther to stigma
Fertilization
Fusion of gametes
Occurs after pollination

9. Double fertilization In the ovule, egg fuses with first sperm cell
Zygote is formed
Zygote develops into a multicellular embryo in the seed

10. Double fertilization, cont.
Two polar nuclei fuse with second sperm cell
Triploid nutritive tissue (endosperm) is formed

11. Mature flowering plant embryo consists of
A radicle
A hypocotyl
A plumule
Cotyledons (one in monocots, two in dicots)

12. For use during germination, a mature seed contains both
A young embryo
Nutritive tissue (stored in endosperm or cotyledons)

13. Ovules Ovaries Structures with the potential to develop into seeds
Structures with the potential to develop into fruits

14. Simple fruits Develop from a single pistil consisting of
Either a single carpel
Several fused carpels
Some are fleshy at maturity
Others are dry

15. Aggregate fruits Multiple fruits
Develop from a single flower with many separate ovaries
Multiple fruits
Develop from the ovaries of many flowers growing close together on a common axis

16. Dispersal methods of seeds and fruits include
Accessory fruits
The major part of the fruit consists of tissue other than ovary tissue
Dispersal methods of seeds and fruits include
Animals
Wind
Water
Explosive dehiscence

17. An accessory fruit

18. Plant growth and development are controlled by
Internal factors like location of cell in plant body
Causes some genes in cell to be turned off and others to be turned on, thus affecting gene expression during development
Environmental factors like changing day length

19. Germination and seedling growth

20. Germination is the process of seed sprouting
Internal factors affecting germination
Maturity of the embryo
Presence or absence of chemical inhibitors
Presence or absence of hard, thick seed coats

21. Germination, cont.
External environmental factors affecting germination include requirements for
Oxygen
Water
Temperature
Light

22. Photoperiodism is any response of plants to the duration and timing of light and dark
In many plants, flowering is a photoperiodic response
Short-day plants
Long-day plants
Intermediate-day plants

23. Photo-periodic responses of short-day and long-day plants
Light treatment
Photo-periodic responses of short-day and long-day plants
Short-day plant
Long-day plant

24. Photoperiodism, cont. Day neutral plants
Flowering is not affected by photoperiod

25. Phytochrome is The photoreceptor in photoperiodism
A family of ~5 blue-green pigments
Each type has two forms named by the wavelength of light they absorb Pr
Pfr

26. Phytochrome, cont.
Pfr is the active form, triggering or inhibiting physiological responses such as
Flowering
Shade avoidance
A light requirement for germination

27. Phytochrome
This pigment occurs in two forms, Pr and Pfr, and readily converts from one to the other. Red light (660 nm) converts Pr to Pfr, and far-red light (730 nm) converts Pfr to Pr

28. Circadian rhythm
A regular period in the growth or activities of a plant or organism
That approximates the 24-hour day
Is reset by the rising and setting of the sun

29. Circadian rhythm, cont. Examples are
The opening and closing of stomata
Sleep movements

30. Plant movements occurring in response to external stimuli
Tropisms
Directional growth responses (i.e., the direction of growth is dependent on the direction of the stimulus)

31. Phototropism Gravitropism Thigmotropism Heliotropism
Response to the direction of light
Gravitropism
Response to gravity
Thigmotropism
Response to contact with a solid object
Heliotropism
Ability of leaves or flowers to track the sun across the sky

32. Gravitropism

33. Heliotropism

34. Plants produce and respond to hormones that
Act as highly specific chemical signals
Elicit a variety of responses that regulate
Growth
Development

35. Hormones Are effective in very small concentrations
Functions of some overlap
Many physiological activities are regulated by interactions of several at once

36. General mechanism of action of plant hormones

37. Plant hormones bind to specific receptor proteins in or on target cells
Binding may trigger production of a second messenger (e.g., Ca2+)
Second messenger may bind to and activate or inactivate certain enzymes

38. Hormones affecting plant growth and development
Auxin is involved in
Cell elongation
Tropisms
Apical dominance
Inhibition of axillary buds by the apical meristem

39. Isolating auxin from coleoptiles

40. Phototropism and the unequal distribution of auxin

41. Hormones, cont. Gibberellins are involved in Stem elongation Flowering
Germination

42. Gibberellin and stem elongation

43. Hormones, cont. Cytokinins Promote cell division and differentiation
Delay senescence
Interact with auxin and ethylene in apical dominance
Induce cell division in tissue culture

44. Auxin-cytokinin interactions
in tissue culture

45. Hormones, cont. Ethylene plays a role in Ripening fruits
Apical dominance
Leaf abscission
Wound response
Thigmomorphogenesis
Senescence

46. Hormones, cont.
Abscisic acid is an environmental stress hormone involved in stomatal closure caused both
By water stress
In seed dormancy

47. Abscisic acid and seed germination
Arrows show where some of the kernels have germinated while still on the ear, producing roots

48. Salicylic acid Helps defend plants against
Pathogens
Insect pests
May bind to a cell receptor to switch on genes to
Fight infection
Promote wound healing