can anyone teaches me reproduction chapter in detail class 10th please in detail
Answers
Types of Reproduction:
There are two main types, viz. asexual and sexual reproduction.
Asexual Reproduction: When a single parent is involved and no gamete formation takes place; the method is called asexual reproduction. No meiosis happens during asexual reproduction.
Sexual Reproduction: When two parents are involved and gamete formation takes; the method is called sexual reproduction. Meiosis happens during gamete formation; which is an important step of sexual reproduction.
Reproduction in Simple Organisms
Binary Fission: Most of the unicellular animals prefer this method for reproduction. These organisms reproduce by binary fission; especially when conditions are favourable, i.e. adequate amount of food and moisture is available. Binary fission is somewhat similar to mitosis. The mother cell divides into two daughter cells; and each daughter cell begins its life like a new individual. The parent generation ceases to exist, after binary fission. Amoeba is a very good example of the organism which reproduces by binary fission.
Multiple Fission: When conditions become unfavourable, i.e. food, moisture, proper temperature, etc. are not available; this is the preferred mode of reproduction by unicellular organisms. The organism develops a thick coating around itself. This is called cyst. The cyst helps the organism to tide over the bad phase. The nucleus divides into several nuclei and each daughter nucleus is surrounded by a membrane. All metabolic activities stop in the organism, after cyst formation. When favourable conditions return, the cyst dissolves or breaks down; releasing the daughter nuclei. The daughter nuclei; in turn; grow into new individuals. Plasmodium and entamoeba undergo cyst stage, when they are not in the body of their prime host, i.e. humans.