1. 1. Reproduction in some forms of life
   
2. 2. Reproduction
   Forms the next generation of species
   The means to continue life (perpetuation of species)
   May be sexual or asexual
   
3. 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 organisms
   
4. 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. 5. Paramecium
   
6. 6. Examples of Asexual reproduction
   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
   
7. 7. Budding in Hydra
   
8. 8. Examples of Asexual reproduction
   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 hasaportion of the central disk, each piece grows the rest of the central disk and the for other arms
   
9. 9. Sea stars
   
10. 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. 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. 12.
13. 13. Asexual or Vegetative Reproduction in Flowering Plants
    
14. 14. 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
    
15. 15. 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 (from the stock and scion)
    
16. 16. 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
    
17. 17. Pistil/Carpel female reproductive part
    Stigma sticky topmost part
    Style slender stalk that supports the stigma
    Ovary swollen base
    Ovules found inside the ovary
    
18. 18.
19. 19. Stages of Sexual Reproduction in Plants
    Formation of Gametes
    Megasporogenesis formation of female gametophyte
    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
    
20. 20. b. Pollination transfer of the pollen grain from the anther to a stigma of a flower
    Self-pollination pollen is transferred from the anther to the stigma of the same flower
    Cross-pollination pollen is transferred from the anther to the stigma of another plant
    
21. 21. 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)
    Embryo + endosperm + covering layers of the ovule seed
    
22. 22. d. Fruit and seed development
    ovary fruit
    ovule seed
    Seed embryo, stored food and seed coat/testa
    Embryo cotyledon, hypocotyl and epicotyl
    
23. 23. 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