1. KEY CONCEPT All plants alternate between two phases in their life cycles.

2. Plant life cycles alternate between producing spores and gametes.
A two-phase life cycle is called alternation of generations.
haploid phase
diploid phase
alternates between the two
fertilization
meiosis
SPOROPHYTE
PHASE
GAMETOPHYTE

3. The spore-producing plant is the mature sporophyte.
sporophyte phase is diploid
begins with fertilized egg
spores produced through meiosis
The gamete-producing plant is the mature gametophyte.
gametophyte phase is haploid
begins with spore
gametes produced through mitosis

4. Life cycle phases look different among various plant groups.
Nonvascular plants have a dominant gametophyte phase.
moss gametophytes look like green carpet
moss sporophytes shoot up as stalklike structures
sporophyte (2n)
gametophyte (1n)
capsule
spores (1n)

5. The sporophyte is the dominant phase for seedless vascular plants.
Fern spores form in sacs, sori, on underside of mature sporophytes (fronds).
sporophyte (2n)
sori

6. A fern gametophyte, or prothallus, produces sperm and eggs.
gametophyte (1n))
rhizoid
A zygote forms on the prothallus, growing into the sporophyte.

7. The sporophyte is the dominant phase for seed plants.
pine trees are typical seed plant sporophytes
female spores produced in female cones
male spores produced in male cones
male spores develop into pollen grains, the male gametophytes
female spores develop into female gametophytes that produce eggs
sperm from pollen travel down pollen tube toward egg
fertilized egg develops into embryo
ovule develops into protective pine seed

8. The sporophyte is the dominant phase for seed plants.

9. Moss life cycle

10. Fern Life Cycle
Fern – (pterophyta) – vascular & nonseed

11. Conifer Life Cycle
Conifers (coniferophyta) – vascular w/ naked seeds

12. Flowering Plant Life Cycle

13. KEY CONCEPT Reproduction of flowering plants takes place within flowers.

14. Flowers contain reproductive organs protected by specialized leaves.
Sepals and petals are modified leaves.
Sepals are outermost layer that protects developing flower
sepal

15. Petals can help to attract animal pollinators

16. A stamen is the male structure of the flower.
filament
anther
anther produces pollen grains
filament supports the anther

17. The innermost layer of a flower is the female carpel.
style
stigma
ovary
stigma is sticky tip
style is tube leading from stigma to ovary
ovary produces female gametophyte

18. Flower Parts

19. Complete and Perfect Flower Monocot Flower
Complete & perfect

20. Incomplete and Imperfect Flower Dicot Flower

21. Incomplete and Imperfect Flower Dicot Flower

22. Complete and Perfect Flower Monocot Flower

23. Simple fruit
simple

24. Aggregate fruit
Aggregate

25. Multiple fruit
multiple

26. Flowering plants can be pollinated by wind or animals.
Flowering plants pollinated when pollen grains land on stigma.
Wind pollinated flowers have small flowers and large amounts of pollen.

27. Animal pollinated flowers have larger flowers and less pollen.
many flowering plants pollinated by animal pollinators
pollen grains
pollination occurs as animal feeds from flower to flower
animal pollination more efficient than wind pollination

28. Fertilization takes place within the flower.
Male gametophytes, or pollen grains, are produced in the anthers.
male spores produced in anthers by meiosis
each spore divides by mitosis to form two haploid cells
two cells form a single pollen grain
pollen grain

29. One female gametophyte can form in each ovule of a flower’s ovary.
four female spores produced in ovule by meiosis
one spore develops into female gametophyte
female gametophyte contains seven cells
one cell has two nuclei, or polar nuclei
one cell will develop into an egg

30. Pollination occurs when a pollen grain lands on a stigma.
pollen tube
sperm
stigma
one cell from pollen grain forms pollen tube
other cell forms two sperm that travel down tube

31. Flowering plants go through the process of double fertilization.
female
gametophyte
ovule
egg
sperm
polar nuclei

32. Flowering plants go through the process of double fertilization.
endosperm
seed coat
embryo
one sperm fertilizes the egg
other sperm unites with polar nuclei, forming endosperm
endosperm provides food supply for embryo

33. Each ovule becomes a seed.
The surrounding ovary grows into a fruit.

34. KEY CONCEPT Seeds disperse and begin to grow when conditions are favorable.

35. Animals, wind, and water can spread seeds.
Seeds dispersed by animals can have nutritious fruits or fruits that cling.

36. Seeds dispersed by wind can have wing- or parachute- like fruits.
Cypselae
Double samaras

37. Seeds dispersed by water can have fruits that float.

39. Seeds begin to grow when environmental conditions are favorable.
Seed dormancy is a state in which the embryo has stopped growing.
Dormancy may end when conditions are favorable.
While dormant, embryo can withstand extreme conditions.

40. Germination begins the growth of an embryo into a seedling.
water causes seed to swell and crack coat
embryonic root, radicle, is first to emerge
water activates enzymes that help send sugars to embryo

41. Germination begins the growth of an embryo into a seedling.
water causes seed to swell and crack coat
embryonic root, radicle, is first to emerge
water activates enzymes that help send sugars to embryo
embryonic shoot, plumule, emerges next

42. Germination begins the growth of an embryo into a seedling.
water causes seed to swell and crack coat
embryonic root, radicle, is first to emerge
water activates enzymes that help send sugars to embryo
embryonic shoot, plumule, emerges next
leaves emerge last

43. Once photosynthesis begins, the plant is called a seedling.

44. KEY CONCEPT Plants can produce genetic clones of themselves through asexual reproduction.

45. Plants can reproduce asexually with stems, leaves, or roots.
Asexual reproduction allows a plant to make copies of itself.
Regeneration is one type of asexual reproduction.
plants grow a new individual from fragment of parent
occurs when piece of a stem, leaf, or root falls off parent plant

46. Vegetative reproduction is another type of asexual reproduction.
stems, leaves, or roots attached to parent plant produce new individuals
specific adaptations include stolons, rhizomes, and tubers

47. Humans can produce plants with desirable traits using vegetative structures.
Vegetative propagation takes advantage of plants’ ability to reproduce asexually.
Humans use one plant with desirable traits to produce many individuals.
cutting of leaves or stems may grow new roots
grafting joins the parts of two plants together to form a hybrid plant

48. KEY CONCEPT Plant hormones guide plant growth and development.

49. Plant hormones regulate plant functions.
Hormones are chemical messengers.
produced in one part of an organism
stimulates or suppresses activity in another part

50. Gibberellins are plant hormones that produce dramatic increases in size.
ending seed dormancy
rapid growth of young seedlings
rapid growth of some flower stalks

51. Ethylene causes the ripening of fruits.
some fruits picked before they are ripe
sprayed with ethylene to ripen when reach destination

52. Cytokinins stimulate cytokinesis.
final stage in cell division
produced in growing roots, seeds, and fruits
involved in growth of side branches

53. Auxins lengthen plant cells in the growing tip.
stimulates growth of primary stem
controls some forms of tropism
A tropism is the movement of plant in response to an environmental stimulus.

54. Plants can respond to light, touch, gravity, and seasonal changes.
Phototropism is the tendency of a plant to grow toward light.
auxins build up on shaded side of stem
cells on shaded side lengthen
causes stem to bend toward light

55. Thigmotropism is a plant’s response to touchlike stimuli.
climbing plants and vines
plants that grow in direction of constant wind

56. Gravitropism is a plant’s response to Earth’s gravitational pull.
positive gravitropism is downward growth (roots)
negative gravitropism is upward growth (shoots)

57. Some plants have rapid responses not involving growth.
Some responses protect plants from predators.
Some responses allow plants to capture food.

58. Photoperiodism is a response to the changing lengths of day and night.
triggers some plants to flower
triggers fall colors/winter dormancy of deciduous trees