Q. What is reproduction? Why it is an essential life process? Or, explain the importance of reproduction in organism. Answer: Reproduction is process of producing new individual. Living organism produce young ones of their own kind by the process of reproduction. Reproduction is essential for the continuation of life from one generation to next generation. It ensures the continuation of similar kinds of individuals, generation after generation. Q. What are the different modes by which animals reproduce? Answer: there are two modes by which animals reproduce. These are: (i) Asexual reproduction and (ii) Sexual reproduction Q. Describe asexual reproduction Answer: Asexual reproduction is kind of reproduction in which single individual new individual of its own kinds. The off spring produced by asexual reproduction are similar to parents and are called clones very small animals like hydra and microscopic organisms like amoeba . Q. How new individuals developed in hydra? Answer: Hydra reproduces by budding. In each hydra, there may be one or more bulges. These bulges are called buds. These buds detached from parent body and develop into new individuals. Q. How new individuals developed in amoeba? Answer: Amoeba reproduces by binary fusion. Amoeba splits its body into two, each part receiving a nucleus and two new amoebae are produced. Q. Write some basic feature of a sexual Reproduction? Answer: Asexual Reproduction Basic features (i) Only one parent organism is involved. (ii) New organisms are genetically identical to the parent(clones) (iii)No gamete formation iv) Cell division involved – mitotic Q. Differentiate between (a) Binary fission and Multiple fission (b) fission and budding (c) fission and fragmentation Answer: Differences between binary fission and multiple fission (a) A single parent organism divides into two new organisms. e.g. Amoeba, Pramecium, Euglena (b) Only single parent organism divides into many new organisms. eg. Plasmodium. Differences between fission and budding Fission (a) A single parent organism divides into two or many new organisms. (b) Parental identity is lost (c) Amoeba, Paramecium, Plasmodium Budding (a) Parent organism forms a bud (outgrowth), it gets separated &form a new organism. (b)Parental identity is maintained (c) Hydra, Yeast ( Unicellular Fungus) Differences between fission & fragmentation Fission (i) It occurs in unicellular organisms (ii)The nucleus & cytoplasm of the parent cell divides & produce two daughter cells. (iii)The daughter cells formed are equal in size. (iv)For example : Amoeba, Euglena Fragmentation (i) It occurs in multicellular organisms. (ii)The organism breaks into two or more parts &each part grows into a new organism. (iii) The new organisms formed are usually unequal in size. (iv) for example : Spirogyra Q. Describe about cloning? Answer: Cloning is the production of an exact copy of a cell, any other living part, or a complete organism. Cloning of an animal was successfully performed for the first time by Ian Wilmut and his colleagues at the Roslin Institute in Edinburgh, Scotland. They cloned successfully a sheep named Dolly . Dolly was born on 5th July 1996 and was the first mammal to be cloned. During the process of cloning Dolly, a cell was collected from the mammary gland of a female Finn Dorsett sheep Q. Describe the process of fertilization in human body? Download full E-notes
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ashish
9/11/2013 07:31:37 am
it is one of the bestteacher
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jsunil
15/12/2013 01:46:46 pm
Science (from Latin scientia, meaning “knowledge”) is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe.In an older and closely related meaning, “science” also refers to a body of knowledge itself, of the type that can be rationally explained and reliably applied
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kartik
29/5/2014 03:35:44 am
1. Explain the following terms:-
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