2. Reproduction Forms the next generation of species The means
to continue life (perpetuation of species) May be sexual or
asexual
3. Asexual reproduction Sexual reproduction Does not involve
gametes or sex cells Occurs in many forms and is performed by many
lower forms of organsims, including plants No genetic variation in
organisms Involves sex cells The sperm and the egg unite to form a
zygote Characteristic of many organisms, including plants, animals
and humans Increases genetic variation among
4. Examples of Asexual reproduction Fission one cell divides
into two either longitudinally, transversely or even diagonally
E.g. Algae Volvox and Ulothrix, paramecia, amoeba, bacteria and
corals Fragmentation pieces of an organism may break off and
develop into whole organisms Colonies of algae, sea anemone, comb
jelly, flatworms
5. Paramecium
6. Budding cells in some areas of an organisms body organize
themselves to form new individuals or buds Hydra (freshwater polyp)
Parthenogenesis (virgin birth) an egg possessing diploid
chromosomes develops into an adult without being fertilized
Daphnia, rotifers, snails, honeybees and sea urchins Examples of
Asexual reproduction
7. Budding in Hydra
8. Paedogenesis smaller larvae develop from bigger larvae and
grow up to become adults Flukes, taperworm, ascaris Regeneration
demonstrated by sea stars; when a sea star is cut into pieces, such
that each arm has aportion of the central disk, each piece grows
the rest of the central disk and the for other arms Examples of
Asexual reproduction
9. Sea stars
10. Conjugation Sexual reproduction in lower forms of life
Genetic material (not necessarily gametes) is transferred between
two individuals through a protoplasmic bridge before allowing
autotomy (voluntary separation of a body part) to take place
Paramecium, bacteria and cyanobacteria, fungi
11. Examples of Asexual reproduction Common bread mold (amag)
reproduces through spores encased inside a capsule- like container
called sporangium Mosses and ferns spore-producing plants Spores
primary structures responsible for asexual reproduction in mosses
and ferns
12. Asexual or Vegetative Reproduction in Flowering Plants
Vegetative Reproductio n Natural Runners Leaf reproduction Tip
layering Artificial Layering Grating and Budding Cutting
13. Natural Vegetative Reproduction Runners grow along the
ground from the parent plant; forms adventitious roots and shoots
at the tips Strawberry Tip layering allows their aerial stems to
arch downwards so that their tips touch the ground Blackberry,
raspberry and spider plant Leaf reproduction new plants develop
along the margins of their leaves katakataka
14. Artificial Vegetative Reproduction Cutting portions of
stems and roots are removed and transferred to loose, damp soil or
sand Herbaceous and woody plants such as rose Layering stimulates
the growth of roots on a stem; a stem is buried in the ground then
cut when roots are formed Grafting and budding splicing together of
two stems or the union of their two cambium layers
15. Sexual Reproduction in Flowering Plants: Floral Parts Calyx
collection of sepals Corolla collection of petals Stamen male
reproductive part Filament slender stalk Anther produces colored
grains called pollen, which contains sperm nuclei
16. Pistil/Carpel female reproductive part Stigma sticky
topmost part Style slender stalk that supports the stigma Ovary
swollen base Ovules found inside the ovary
17. Stages of Sexual Reproduction in Plants a. Formation of
Gametes a. Megasporogenesis formation of female gametophyte b.
Microsporogenesis formation of male gametophyte Sporogenesis
involves a reduction division process that produces haploid
gametes: egg in embyo sac and sperm in the pollen grain
18. b. Pollination transfer of the pollen grain from the anther
to a stigma of a flower a. Self-pollination pollen is transferred
from the anther to the stigma of the same flower b.
Cross-pollination pollen is transferred from the anther to the
stigma of another plant
19. c. Double-fertilization Pollen grain with two nuclei
(generative and tube nucleus) generative nucleus moves into the
pollen tube and forms two sperm nuclei tube nucleus grows through
the stigma, style and into the ovule, clearing the way for the
entry of sperm nuclei 1 sperm nuclei (N) + 1 egg (N) = zygote (2N)
1 sperm nuclei (N) + 2 polar nuclei = endosperm (3N)
20. d. Fruit and seed development ovary fruit ovule seed Seed
embryo, stored food and seed coat/testa Embryo cotyledon, hypocotyl
and epicotyl
21. e. Seed Germination Viability ability of the seed to
germinate Conditions: a. Suitable temperature ( between 16C and 27
C) b. Plenty of moisture c. Sufficient oxygen Seedling young plant
that develops out of a plant embryo from a seed radicle root
hypocotyl shoot cotyledons seed leaves