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Passing it On

Passing it On. Unit A: Topic 3. Living organisms display a wide variety of methods or reproductive strategies for passing on their genetic information to their offspring. Asexual Reproduction. Involves only one parent Offspring are identical to the parent

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Passing it On

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  1. Passing it On Unit A: Topic 3

  2. Living organisms display a wide variety of methods or reproductive strategies for passing on their genetic information to their offspring.

  3. Asexual Reproduction • Involves only one parent • Offspring are identical to the parent • Four main types of asexual reproduction are: • Binary fission • Budding • Spore Production • Vegetative Reproduction

  4. Binary Fission • Occurs in unicellular organisms • Cell splits in two producing identical offspring • Examples: Bacteria and protists • http://www.youtube.com/watch?v=NTBzPP0Aygk&feature=related

  5. Budding • Parent produces a small, attached (identical) version of itself. • The offspring can stay connected or detached • Examples: Coral, yeast, hydra. http://www.youtube.com/watch?v=489CSop00sY

  6. Spore Production • Similar to seeds • Produced by the division of parent cells. • Examples: Fungi, ferns, moulds, and algae. • Many spores are produced to ensure some survival. • Some fungi and algae produce zoospores which move with a tail-like flagella http://www.youtube.com/watch?v=eZ40LDWt678&feature=related

  7. Vegetative Reproduction • There are many different types including runners, tubers and suckers. • Examples: Strawberry plants, potatoes, and aspen trees. • http://www.youtube.com/watch?v=fPraEesXRSs

  8. Asexual Reproduction • Asexual reproduction can also happen without special cells. • In the meristem of plants, found in the tips of roots and stems, cells rapidly divide. • Cutting from a parent stem may be used to produce new plants that clones (exact copies) if that stem is planted. http://www.youtube.com/watch?v=ZLGz-Ykzxqo

  9. p. 29

  10. pollen grains pedicel

  11. Go through the Structure of Plant Bill Nye http://www.accesslearning.com/videodetail.cfm?asset_guid=ff3f26ce-0c62-4848-8373-d33a509c5238

  12. Sexual Reproduction in plants • Most plants will produce both male and female gametes in one plant, but some only produce male or female gametes. • Pollen, which is found on the stamen, has the male gametes in it. • Ovules, which are found on the pistil, contain the female gametes.

  13. Pollen • Self-Pollination: when the pollen from the anther is transferred to the stigma. • Cross-pollination: when the pollen from one plant is carried to a different plant. • http://www.youtube-nocookie.com/embed/xHkq1edcbk4?rel=0 THE BEAUTY OF POLLINATION (4 MIN) • How can pollination occur? • Wind, water, animals/birds

  14. Fertilization • Fertilization: When the gametes in the pollen join with the gametes in the ovum (on the same plant). • Cross-fertilization: When the pollen from one plant fertilizes another plant. • http://www.youtube.com/watch?v=KMQtLWpAdXI&feature=related

  15. Sexual Reproduction in plantshttp://www.teachersdomain.org/asset/oer08_vid_flowers • Pollen grains, each of which contains a sperm nucleus, are brought to the female eggs in the ovaries. • The pollen grain grows an extension called a pollen tube. This pollen tube grows until it reaches the ovule. • The sperm nucleus travels down the tube to fertilize the egg. • A zygote is formed and contains the genetic information from both parents. • It then goes through many cell divisions to form a multicellular embryo containing miniature leaf, root, and stem. • The embryo is protected by a seed and can stay dormant for a long time.

  16. Sexual Reproduction in animals • Involves specialized sex cells called gametes • Fertilization – the union of sperm and egg

  17. Sexual Reproduction in animalshttp://www.youtube.com/watch?v=UgT5rUQ9EmQ&feature=related • Fertilization can occur internally or externally. • Internal fertilization occurs in insects, reptiles, birds, mammals, some fish and amphibians. • Results in a high rate of success because egg cells are protected. • External fertilization occurs in sponges, most worms, many fish and amphibians. • Results in a low rate of success because egg cells are exposed to harsh climates and predators.

  18. Sexual Reproduction in Bacteria • Bacterial Conjugation • A connection forms between two cells. Genetic material is transferred directly from one cell to another • Cells will then go through binary fission to create more cells http://www.youtube.com/watch?v=O-EdX4MaMFE&feature=fvwrel

  19. Asexual Reproduction Advantages Disadvantages If conditions are unfavourable, the entire population could be wiped out. • Only need one organism • Doesn’t require any specialized cells to bring gametes together • Can produce lots very quickly

  20. Sexual Reproduction Advantages Disadvantages Perfect timing and conditions are required Two partners are needed Takes lots of energy Only produces limited offspring • Provides lots of variation which helps species survive environmental change

  21. What are some organisms that reproduce both sexually and asexually? • Some species of grasses • Sunflowers • Roses • Aphids • Sponges • Fungi – some types of fungi can produce asexually by using spores, but they can also produce sexually by using zygospores. Zygospores contain genetic information from two different sources.

  22. Bill Nye Genetic Diversity • http://www.accesslearning.com/videodetail.cfm?asset_guid=03744310-4CBB-4CB7-996B-D6D23257AB7F

  23. Review Assignment • What is a zygote and how is it formed? • List three examples of asexual reproduction. • List three ways pollination can occur. • What is similar about sperm and egg cells? What is different? • List the steps of fertilization and embryo development in animal sexual reproduction. • List the steps of fertilization and embryo development in plant sexual reproduction.

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