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Reproduction: Asexual vs. Sexual Reproduction is important for the survival of all living species. Without a way to reproduce, life would come to an end. Two types of reproduction: Asexual reproduction involves only one parent & results in an exact duplicate of an organism. There are many types of asexual reproduction. (budding, binary fission, fragmentation, regeneration, spores, cloning, etc…) Sexual reproduction involves the joining of male & female sex cells, called gametes. The male’s sperm & female’s egg are joined in a process called fertilization & results in the production of a zygote. Advantages & disadvantages of each type of reproduction: Asexual Reproduction 1. Asexual reproduction is common among plants, single-celled organisms & simple animals. 2. Asexual reproduction requires only one parent. 3. Asexual reproduction has the advantage of producing large numbers of offspring very quickly. 4. The offspring produced by asexual reproduction, from the same parent, are identical to one another & they are identical to the parent (clones) which prevents adaptations from occurring. 5. If a species of organism shows no variation & cannot adapt it may become extinct. Sexual reproduction 1. Sexual reproduction is common among higher animals & flowering plants. 2. Sexual reproduction requires sex cells produced by two parents. (sperm from males & eggs from females) 3. Sexual reproduction is more complex & slower than asexual reproduction. 4. The offspring produced by sexual reproduction have genetic variation. They may look like their parents, but they are not identical. 5. Amongst populations of wild animals & plants, individuals show variation as a result of sexual reproduction. This variation allows them to adapt to the environment. Sexual Asexual Sexual reproduction Asexual always reproduction requires does not require Definition fertilization fertilization so so it requires only one parent the sex cells is involved. of two parents. Sexual Advantages Asexual The offspring will be different from its parents. This variation Asexual reproduction allows the species to is usually faster and adapt to its easier, so a new plant surroundings. or animal can colonize an area more quickly. “Good” traits are passed on and A mate does not have strengthen the species to be found so no travel which increases their is involved which saves survival rate. energy. The fertilized egg Less complex and more reliable. (zygote) can sometimes survive in adverse conditions (drought). Sexual Disadvantages Asexual The new organisms are genetically identical to their Often slower than parents. (they will all asexual look exactly the reproduction, more same as each other). complex, and less Organisms with no reliable. variation that cannot adapt it may become extinct. Sexual Examples Asexual Plants that make spores (moss, ferns). Fungi make spores (mold, mushrooms). Most animals reproduce sexually (fly, human, snake, Single cells, which frog). reproduce by binary fission All flowering plants and or splitting in two (amoeba, bacteria). those that make seeds reproduce sexually. Budding (spider plant, hydra). (daffodil, grass, rose, oak tree). Runners (grass, strawberries). Fragmentation (planarians). Regeneration (starfish). Examples of Asexual Reproduction: Spores: Ferns, mosses molds & mushrooms produce spores which are dispersed, then under favorable conditions a single spore develops into a new individual. Spores Binary fission: Amoebas, bacteria and other singlecelled organisms divide to form two identical cells that become the same size. Binary fission Budding: Some bacteria, plants, fungi, yeast, sponges, corals and hydras form new organisms when part of the parent breaks off to form a daughter cell that grows into a new individual that is identical to the parent. Budding Runners: Potatoes, strawberries, some grasses and other plants can form horizontal stems that grow on top of or just below the ground which can produce new plants horizontally at nodes or tips along the stem. Runners Fragmentation: Some plants, planarian and other worms can be split into many fragments that each grow into new identical individuals. Fragmentation Regeneration: Type of fragmentation in which starfish, lizards & sponges can grow back body parts that are damaged or lost.