Perpetuation of life

1. Perpetuation of Life

2. REPRODUCTION
•one of the characteristics of life
•biological process in which new
individual organisms are
produced
•may it be sexual or asexual

3. Sexual Reproduction
•flowers play a major role in sexual
reproduction as it houses the structures
for this process
•Four main flower organs: Stamen and
Carpel (Reproductive) and Petals and
Sepals (Sterile)

4. Stamen
•male reproductive organ, which
produces the pollen, which contains
the sperm cell.

5. Carpel
•the female reproductive organ has the following
structures: stigma, style and ovary.
•stigma is the sticky end of the carpel where
pollen is trapped during the process of
pollination.
•The style is a slender neck where the sperm cell
from the pollen can travel to the base of the

6. • In the ovary are ovules, female gametes, which
when is fertilized by the sperm becomes the seeds
of a fruit.
• Sometimes, a flower has only one carpel, or has
more than one carpel, which is fused, it is called a
pistil.

7. Pollination
•the process of transferring pollen from an
anther to a stigma.
•needed in order for fertilization to occur
•self-pollination and cross-pollination

8. Self-pollination vs. Cross-pollination
• Self-pollination- wherein the pollen is transferred to
the stigma of a plant’s own flower
• Cross-pollination- wherein pollen from a different
plant is delivered to a stigma of a flower of a different
plant.
• Compared to self-pollination, cross-pollination can
increase genetic diversity of plants as genes from two

9. Biotic Pollinators
a. Bees- rely on nectars from flowers for they food, as
such they pollinate flowers with delicate, sweet fragrance.
They are also attracted to bright colors, yellow and blue.
Red might be dull to them, but flowers were able to
evolve by creating ultraviolet markings as nectar guides
as bees can see ultraviolet light.

10. b. Moths and butterflies – like bees, detect odors
and pollinate flowers with sweet fragrance.
Thedifference in activity of a butterfly and a moth
allows pollination of different plants, as butterflies
are attracted to bright flowers they are day
pollinators while moths, which are mostly active at
night, are attracted to white or yellow flowers which
are very distinct at night.

11. c. Bats – like moths are attracted to sweet
smelling lightly colored flowers which stand
out at night.
d. Flies – are attracted to red, fleshy flowers
with a rank odor reminiscent of decaying
meat.

12. e. Birds – do not have a keen sense of smell,
thus, flower fragrance is not a flower character
trait by plants pollinated by birds. Birds are
usually attracted to bright flowers such as red and
yellow. Also, their nectar have high sugar content
which is needed by birds.

13. After the process of pollination, the process of
fertilization might occur, which can result in the
development of a seed which houses the embryo
of a future plant. Below is the process of
gametophyte production, pollination, double
fertilization and seed development.

14. ASEXUAL REPRODUCTION
• some organs grow indeterminately due to tissues
that can actively divide (meristem- actively dividing
cells) and revert to non-specialized structures
(parenchyma tissues).
• This indeterminate growth can lead to a form of
reproduction called asexual reproduction, as these
organs can separate from the parent plant with the
ability to grow and develop

15. Fragmentation
• the most common method of asexual reproduction, can
occur through growth from a stem, leaf, root and other plant
organ which gained the ability comparable to parent plant.
Apomixis
• plants can also produce seeds without the process of
pollination and fertilization occurs
• when diploid cells in the ovule creates an embryo, this
can later result in the formation of a seed.

16. Artificial propagation
a. Grafting: is composed of the stock (rooted part
of the plant) and the scion (the attached part). This
is usually done to hasten the reproductive ability of
a plant, grow a selected fruiting plant, etc.

17. b. Layering: like what happens to a runner,
wherein, a shoot of a parent plant is bent and is
covered by soil. This stimulates root growth, after
which, the plants can be separated.

18. c. Cutting: is done to propagate a plant by cutting
the stem at an angle of a shoot with attached
leaves. Sometimes, growth stimulator is given.

19. Advantage and Disadvantage of Both
Types of Reproduction
Sexual Reproduction
Advantage
• Genetic variability
• Dispersal
• Large number
• Adapted to unstable and difficult environments
• Growth can be suspended

20. Disadvantage
•Need for a pollinator
•Prone to predation
•Time constraint

21. Asexual Reproduction
Advantage
• No need for pollinator
• Pass all good genetic material as offsprings 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

22. Disadvantage
• Clones are prone to diseases, predation, etc.
• Cannot be dispersed long distances
• Prone to environmental fluctuating conditions