Notes

1. INTRODUCTIONTO
PLANT REPRODUCTION

2. REPRODUCTION is one of the
characteristics of life. It is a biological
process in which new individual organisms
are produced, may it be sexual or asexual.
• Sexual reproduction involves the union of
gametes (egg cell and sperm cell) through
fertilization.
• Meanwhile, asexual reproduction
involves the creation of cloned offspring
from a parent organism.

3. Y2Mate.is -Types of
Reproduction in Plants-
bgLdf4XUrY0-720p-
1658535037164.mp4

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

5. 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

6. SEXUAL
REPRODUCTION

7. FLOWER
PARTS

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

9. 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.

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

12. 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

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

14. Tiger Lily – a complete flower

15. Female Squash Flower Male Squash Flower
Incomplete Flowers

16. Female Squash Flower Male Squash Flower
Incomplete Flowers

17. 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

19. Pollinators

20. ASEXUAL
REPRODUCTION

21. NaturalVegetative
Propagation
This occurs when plants grow and
develop naturally without any human
interference. Natural vegetative
propagation can be enabled by the
development of adventitious roots.
Thus, new plants may emerge from
the roots, stem and leaves of the
parent plant.

22. STEM
Runners grow horizontally above the
ground.The buds are formed at the
nodes of the runners.

23. ROOTS
New plants emerge out of swollen,
modified roots known as tubers. Buds
are formed at the base of the stem.

24. LEAVES
Leaves of a few plants get detached
from the parent plant and develop
into new plants.

25. BULBS
Bulbs have an underground stem to which the
leaves are attached.These leaves are capable of
storing food.The centre of the bulb contains an
apical bud that produces leaves and flowers.
Shoots are developed from the lateral buds.

26. ArtificialVegetative
Propagation
This is a type of vegetative
reproduction carried out by humans in
the fields and laboratories.The most
common types of vegetative
reproduction occurring artificially
include:

27. CUTTING
In this, a part of a
plant, specifically a
stem or leaf is cut
and planted in the
soil.These cuttings
are sometimes
treated with
hormones to induce
root development.
The new plant is
formed from the
adventitious roots
developing from the
cutting.

28. GRAFTING
In this, the cutting
from some other
plant is attached to
the stem of a plant
rooted in the
ground.The tissues
of the graft
become integrated
with the tissues of
the rooted plant
and develop as a
single plant over
time.

29. LAYERING
In this, the stem of
the plant is bent to
the ground and
covered with soil.
Adventitious roots
emerge from the
plant parts covered
with the soil.This
attached stem with
developing roots is
known as a layer.

30. TISSUE CULTURE
In this, the plant cells
from different parts of
a plant are cultured in
the laboratory to
develop a new plant.
This technique is
helpful in increasing
the number of rare
and endangered plant
species that are
unable to grow under
natural conditions.

31. SEXUAL REPRODUCTION
ADVANTAGES
•Genetic variability
•Dispersal
•Large number
•Adapted to
unstable and
difficult
environments
•Growth can be
suspended
DISADVANTAGES
•Energy expensive
•Need for a
pollinator
•Prone to
predation
•Time constraint

32. ASEXUAL REPRODUCTION
ADVANTAGES
•No need for pollinator
•Pass all good genetic
material as offspring are
clones of parents
•Can grow rapidly in a
stable environment, as
the offspring are
genetically adapted to
the environment
•Strong seedlings,
prevents predation
•Energy economical
DISADVANTAGES
•Clones are prone to
diseases, predation,
etc.
•Cannot be dispersed
long distances
•Prone to
environmental
fluctuating
conditions

33. STRUCTURE FUNCTION
RELATIONSHIP AMONG
FLOWERS, FRUITS AND
SEEDS

34. Y2Mate.is - Seed Dispersal by
Explosion-OB0P3mx_lxY-720p-
1654695519951.mp4

35. “Why do plants need to disperse
their seeds?”
“What are some other ways you
think seeds are dispersed besides
what you observed in the video?”

36. In biological systems, there is a
distinct relationship between an
organism’s structure and its
corresponding function.

37. FLOWER

38. VEGETATIVE PART
a. Receptacle – holds the floral parts of the
flower
b. Sepal – modified leaves that protects a flower
in bud and holds the petals when in bloom
c. Calyx – collective term for the sepals
d. Petal – modified leaves that surround the
reproductive organ or plants; normally colourful,
and with odor, to attract pollinators
e. Corolla – collective term for petals
f. Inflorescence – cluster of flowers

39. REPRODUCTIVE PART
a. Stamen – male reproductive organ
b. Filament – stalk that holds the anther at the
end
c. Anther – produces the pollen which houses the
sperm cell
d. Carpel – Female reproductive organ. Singly or
fused, is called a pistil
e. Style – the slender neck of the carpel which
holds the stigma at its end.
f. Stigma – is a structure with sticky substance
which traps pollen
g. Ovary – the bulbous structure of the carpel
which contains the ovule
h. Ovule – has the egg cell of the plant.

40. ADAPTIVE MECHANISMS
a. As the flower is important in the development
of a fruit and the eventual dispersal of the seed
for plant propagation, it has evolved different
adaptive mechanisms.
b.This structure to function relationship is
important as the plant should be able to attract
specific pollinators to increasing the success rate
of its propagation.
c. Competition among plants over one pollinator
may result in lesser chance of propagation.

41. FRUITS

42. Fruits – structures that not only protect the
seeds of plants but also aid in their dispersal;
derived from the maturation of a flower’s ovary
a.The ovary walls eventually become the
pericarp during development.
b.The pericarp is further divided into three parts:
the exocarp or skin, the mesocarp or the flesh
and the endocarp, which is the core.
c. Depending on fruit adaptations, the pericarp
can be stony, woody, fleshy as such the endocarp
might not be fleshy, the exocarp might be
rubbery or woody, etc.

43. For example: the apple’s seed and fruit is
protected by an accessory fruit which formed
from the fleshy receptacle.This ensures that
the seed will not be harmed during the
consumption of the fleshy receptacle, as the
fruit is not eaten, rather is thrown, aiding in its
dispersal.
Again, this is an example of a structure
function relationship not only in one organ (the
fruit) but between the flower and the fruit that
was formed.

44. 4 kinds of fruit
1. Simple Fleshy
fruits- contain
one or more
seeds.
Ex: Apples, Peach,
grape, tomato,
pumpkin

45. 4 Kinds of fruit
2. Aggregate fruit-
Most berries.
Many female parts
fuse to form one
fruit.
Ex: Blackberries,
strawberries,
raspberries

46. 4 Kinds of fruit
3. Multiple fruit-
Flowers fuse to
form one fruit.
Ex: Pineapples,
figs

47. 4 Kinds of fruit
4.. Dry fruit- Fruits
that are dry.
Ex: Nuts, grains,
seed pods

48. SEEDS

49. 1.The seed or mature ovules contain the
embryo, which will eventually germinate and
grow if properly dispersed in a favorable
environment.
2.To protect the embryo from harsh
environmental conditions, it goes into a state
of dormancy until a period for favorable
growth and development arrives.
3.To protect the embryo, the seed coat has an
hardened outer covering which protects it
from physical or chemical disturbances

50. SEED
DISPERSAL

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