1 / 24

Reproduction

Reproduction. Asexual Reproduction. What is reproduction?. Reproduction is the process by which organisms produce more of their own kind. Think about it – Without reproduction, all life on earth would no longer exist. . Reproduction:. Reproduction. The Continuity of Life.

paul
Télécharger la présentation

Reproduction

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Reproduction Asexual Reproduction

  2. What is reproduction? Reproduction is the process by which organisms produce more of their own kind. • Think about it – Without reproduction, all life on earth would no longer exist.

  3. Reproduction: Reproduction The Continuity of Life Sexual Reproduction Asexual Reproduction

  4. What is Asexual Reproduction? • Only one parent is involved. • Offspring are genetically identical to their parents. • All cells that come from a single cell are genetically identical to it and to each other; they are all clones.

  5. Types of Asexual Reproduction • Mitosis - is the exact duplication of the nucleus of a cell so as to form two identical nuclei during cell division.

  6. Types of Asexual Reproduction 2.Binary Fission - occurs in one-celled organisms such as the ameba and paramecium. The nucleus divides by mitosis and the cytoplasm divides, forming 2 new daughter cells of equal size.

  7. Types of Asexual Reproduction 3. Budding - Occurs in Hydra and yeast. The division of cytoplasm is unequal so one of the daughter cells is larger than the other. The daughter cells can separate or remain attached.

  8. More examples of budding include: Sponges, Corals and Jellyfish…

  9. Types of Asexual Reproduction 4. Sporulation - occurs in molds, mosses, etc • Spores are produced in large numbers by mitosis. • Spores are surrounded by a tough coat to help them survive harsh environmental conditions.

  10. Types of Asexual Reproduction 5.Regeneration - Refers to the replacement or regrowth of lost or damaged body parts

  11. Some of these animals can also grow new organisms from the severed pieces (Segmented Worms and Sea Stars)

  12. Types of Asexual Reproduction 6.Vegetative Propagation – Occurs only in plants (vegetative). New plants develop from the roots, stems, or leaves of the parent plant.

  13. 3 methods of vegetative propagation -tubers -bulbs -runners

  14. Taro- Japanese potato Tubers Tubers are underground food stores which stores food over the winter and provides a new plant with food until it can make its own. Examples: potato, artichoke, yam, cassava, water chestnut, arrowroot Food made by the new plant is sent to make new tubers. Thereby reproducing itself.

  15. Bulbs • E.g. daffodils, lilies

  16. Runners Runners are side shoots which grow out from the parent plant. Buds form at points along the runner and eventually these buds form roots and grow into new plants. Examples: spider plant (Anthericum), strawberry (Fragaria x ananassa)

  17. Artificial Propagation • 2 methods used to cultivate plants asexually -taking cuttings -grafting

  18. Cutting Cuttings are small pieces of stem with some leaves attached, the new plant grows from this. They can be placed in moist soil or water (and sometimes dipped in rooting powder).

  19. Grafting A cut stem of one plant (with good flower or fruit growth) (the graft) is taken and firmly attached to the rootstock of another plant (which has a strong, established root system) (the stock). Examples- roses, fruit trees

  20. Commercial aspects Artificial propagation has allowed us to adapt and improve plants for our own use. Some of the benefits include: • Quick production of large numbers of genetically identical plants. • Specific varieties, desired features or consistent quality can be produced especially in fruit, flowers.

  21. Types of Asexual Reproduction 7. Parthenogenesis • Offspring can arise from unfertilized eggs. • Includes some Fish, Reptiles, Amphibians and Aphids. • Most of these species can switch between Sexual and Asexual Reproduction. (depending on conditions)

  22. Example: Bees – unfertilized eggs become male drones - fertilized eggs – female workers or queens

More Related