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Asexual vs. Sexual Reproduction Modified from: www.wayzata.k12.mn.us/ems/images/stories/academics/7th%2520Grade%2520Gol d/Corens/asexual_vs._sexual_reproduction.ppt www.wayzata.k12.mn.us/ems/images/stories/academics/7th%2520Grade%2520Gol d/Corens/asexual_vs._sexual_reproduction.ppt
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Asexual reproduction A form of reproduction which does not involve meiosis or fertilization. Asexual reproduction = one parent. The primary form of reproduction for single- celled organisms such as archaea, bacteria, and protists. Many plants and fungi reproduce mostly asexually as well.
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Sexual Reproduction Results in increasing genetic diversity of the offspring. Characterized by two processes: meiosis, halving of the number of chromosomes fertilization, combination of two gametes and the restoration of the original number of chromosomes During meiosis, chromosomes usually cross over = genetic recombination. Primary method of reproduction for the vast majority of visible organisms, including almost all animals and plants.
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Binary Fission Asexual Cell splits and replicated DNA goes with each part Prokaryotes, Bacteria + Fast and easy - Everybody has the same DNA
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Bacterial Conjugation Asexual, “Sexual” A bacteria shoots out a tube and sends a piece of its DNA to another bacteria Bacteria + Mixes DNA - “Parent” loses a little piece of DNA
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Fragmentation/ regeneration Asexual Body of parent breaks and produces offspring Fungi, moss, sea stars, planarian + Easy - Parent broken, same DNA
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Fragmentation/ regeneration Moss
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Budding Asexual Offspring grows out of parent Yeast, hydras + Fast, somewhat easy - Same DNA
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Spore Formation Spore Formation – spores = small specialized cells that contain a nucleus and cytoplasm surrounded by a thick outside wall which protects the spore. Under the right conditions the spore can rise to a new organism. Found in bacteria, molds, yeast, mushrooms, mosses, ferns and some protozoans.
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Spore formation
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Vegetative Reproduction
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Bulb = Short underground stem surrounded by thick leaves. Contain stored food. As the plant grows it produces new bulbs which will grow into new plants. Tulips, onions, and lilies.
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Tuber = enlarged part of an underground stem that contains stored food. Potatoes are tubers. “Eyes” = tiny buds that can form a new potato plant. How you plant potatoes. Great potato famine.
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Runner or stolen = horizontal stem above the ground with buds. If a bud touches the ground it will form roots and stems and start a new plant. Strawberries.
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Sexual Reproduction
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Pollination Sexual Reproduction Pollen is delivered to female part of plant Flowering plants + Plants don’t have to move, mixes DNA - Need external source for pollination to take place; wind, bee, bat, butterfly etc.
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Pollination
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Sexual Reproduction DNA from 2 individuals merge to form one Animals, Plants + Diverse DNA - Takes a long time, 2 individuals needed
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Sexual Reproduction
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