ppt is based on reproduction in flowering plants

1. Introduction to Plant
Reproduction
23.1

2. Reproduction
 Sexual reproduction
–Joining of an egg and sperm
 Asexual reproduction
–A single organism replicating its
genetic material to split into two
identical organisms.

3. Vegitative Reproduction
 A form of asexual reproduction where
a new plant grows from parts of an
existing plant.
 Fast reproduction
 Examples:
– Strawberry runners
– Moss fragmentation
– Potato eyes and buds

4. Alteration of Generations

5. Alteration of Generations
Of Nonseed Nonvascular Plants

6. Alteration of Generations
Of Nonseed Vascular Plants

7. Alteration of Generations
Of Naked Seed Vascular Plants

8. Alteration of Generations
Of Flowering Seed Vascular
Plants

9. Alteration of Generations
Fertilization:
 Nonvascular plants- Need a film of
water for the sperm to reach the
egg.
 Vascular plants- Do not need
water for the sperm to reach the
egg.

10. Alteration of Generations
As plants evolved, the sporophyte
generation became larger:
 Nonvascular plants- Sporophyte
depends on the gametophyte for
support and nutrition.
 Vascular plants- Sporophyte lives
independent of the gametophyte.

11. Moss reproductive
cycle
 Gametophyte dominant
–Male= Antheridium
–Female= Archegonium
Archegonium
Antheridium

12. Moss reproductive
cycle
 Antheridium- Male produces
flagellated sperm that need water to
get to the archegonium.
 Chemotaxis- Female archegonium
produces chemicals that attract/direct
the sperm.

13. Moss reproductive
cycle

14. Moss reproductive
cycle
 Sporophyte- Depends on the
gametophyte for support and
nutrition.
 Protonema- Spores that land in a
favorable spot develop into a
protonema (gametophyte
generation).

15. Fern reproductive cycle
 Sporophyte dominant
 Frond- feathery stems of a fern
 Sorus- underneath the frond
–Produces spores

16. Fern reproductive cycle
 Prothallus
–The fern spore grows into a
prothallus when it lands on damp,
rich soil.
–Heart shaped
–Contains Antheridia
& Archegonium

18. Conifer reproductive
cycle
 Sporophyte dominant
 Heterosporous- Produces two kinds
of spores that develop into male and
female cones.
– Female cones
–Made of many scales
–2 ovules at the base of each scale
–Each ovule produces a
Megaspore which develops into
the female archegonia.

19. Conifer reproductive
cycle
– Male cones
–Made of small scales that form
microspores
–4 microspores develop into a
single pollen grain
–Pollen grains are the
male gametophyte that
are transported on air
currents

21. Chapter 23.2
Flowers

22. The Parts of a Flower
• Most flowers have
four parts:
• sepals,
• petals,
• stamens,
• Carpels
(pistils)

23. The parts of a flower
• Sepals protect the
bud until it opens.
• Petals attract
insects.
• Stamens make
pollen.
• Pistils (carpel) grow
into fruits which
contain the seeds.

25. Stamen (male)
• Anther: pollen
grains grow in the
anther.
• When the grains
are fully grown, the
anther splits open.
• Filament: holds the
anther

26. Pistil (female)
• Stigma
• Style
• Ovary
Stigma – sticky place for
pollen to attach
Style – where pollen nuclei
travels to reach the egg
Ovary – where egg is located

27. Modifications in
Flowers
 Complete flowers – have all four
organs (sepals, petals, stamens, and
pistils)
– M orning glory and tiger lily
 Incomplete flowers – lacks one or
more of the four organs
– Squash and corn

28. Tiger Lily – a complete flower

29. Female Squash Flower Male Squash Flower
Incomplete Flowers

30. Modifications in
Flowers
 P erfect flowers- Have both stamens
and pistils (E x: Lily)
 Imperfect flowers- E ither have a
functioning stamen or pistil, but not
both
E x : Cucumber, Squash

31. Pollination Mechanisms
 Animal pollination
– hummingbirds & bees transfer pollen from
plant to plant
– Flowers are brightly colored or highly
scented
 Wind pollination
– lightweight and are carried by wind
– Small flowers with little color or scent
 Self pollination
– Able to pollinate flowers on same plant
– Have both pistel and stamen

32. Pollinators

33. PHOTOPERIODICITY
 Plants flower based
on the number of
hours of darkness
they are exposed to
 Short-day plants -
flower when days
are short (fall,
winter, spring)
Ex: Pansy,
Poinsettias

34. PHOTOPERIODICITY
 Long-day plants -
flower when days
are long (summer)
 Examples:
– Potatoes
– Clover
– Spinach

35. PHOTOPERIODICITY
 Intermediate-day
plants- Grow when
darkness is about
equal to daylight.
E x : Sugar Cane

36. PHOTOPERIODICITY
 Day-neutral plants-
Hours of darkness
does not effect
flowering, as long as
there is enough
daylight to perform
photosynthesis.
E x: Corn, tomatoes,
cotton, roses

37. Chapter 23.3
Flowering P lants

38. Flowering Plant
reproductive cycle
 Sporophyte dominant
 Ovary- produces 4 megaspores, but 3
disintegrate and only one remains.
 Double fertilization – requires 2 sperm
to fertilize the egg and make a seed.
 Seed – embryo (cotyledons),
endosperm (food for embryo), seed
coat (protect seed)

39. Flowering Plant
Reproduction

40. 4 kinds of fruit
1. Simple Fleshy
fruits- contain
one or more
seeds.
Ex: Apples, Peach,
grape, tomato,
pumpkin

41. 4 Kinds of fruit
2. Aggregate fruit-
Most berries.
Many female
parts fuse to
form one fruit.
Ex: Blackberries,
strawberries,
raspberries

42. 4 Kinds of fruit
3. Multiple fruit-
Flowers fuse to
form one fruit.
Ex: Pineapples,
figs

43. 4 Kinds of fruit
4.. Dry fruit- Fruits
that are dry.
Ex: Nuts, grains,
seed pods

44. Seed Dispersal
 Water
– Coconuts
 Wind
– Dandelions
 Animals
– Fruits attract animals that will eat the
seeds so that the seeds can be carried
far away where it won’t have to compete
with its parent.

45. Seed Germination
 Requires:
– Water (swells and breaks seed coat)
– Oxygen (cell respiration as seed grows)
– Optimal Temperature (each plant requires
a certain temperature to begin growth)
Seeds will lie dormant in their hard seed
coats waiting for optimal conditions.