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• Reproduction: Biological process in which parent organisms produce child organism similar to them.
• Modes of reproduction – Sexual reproduction, Asexual reproduction
• Asexual reproduction: single parent gives rise to new offspring. E.g. Reproduction in hydra
• Sexual reproduction: Reproduction takes place by the fusion of male and female gametes. E.g. Reproduction in humans
• Difference between sexual and asexual reproduction
  

  Sexual Reproduction	Asexual reproduction
  Involves two parents	Involves single parent
  Production and fusion of male and female gametes	No production or fusion of gametes
  Offspring is similar to parents and may or may not have characters as that of their parents	Offspring produced is identical to their parents
  It occurs by the process of fertilisation	It occurs by budding, fragmentation, etc
  E.g Reproduction in flowering plants, humans, etc	E.g. Reproduction in hydra,

• Human Male reproductive system:
  • Reproductive system include reproductive organs pair of testis, two sperm ducts and a penis.
  • Male gamete sperm is produced by testis.
  • Sperm cell possess 23 chromosomes.
  • Gametes contains half the number of chromosomes than the normal body cells.
  • Testis is located in the scrotum in lower abdominal cavity where sperms are produced.
  • Structure of sperm cell consist head, middle piece and tail.
• Human Female reproductive system:
  • Reproductive system of female includes pair of ovaries, pair of oviducts i.e. fallopian tubes and the uterus.
  • Ovaries produce female gametes called ova or egg with half the number of chromosomes.
  • Uterus is part of the female body where the baby develops.
• Fertilization : Fusion of male and female gametes (sperm and ovum) to form a zygote or egg
• Types of fertilization –
  • Internal fertilization: Fertilization taking place inside the female body is called internal fertilization. E.g. Reproduction in humans
  • External fertilization: Fertilization of male and female gametes outside the female body is called external fertilization. E.g. Reproduction in frog
  • In vitro fertilization (Test tube baby):
    • Carried out in women whose oviduct is blocked.
    • Male and female gametes are allowed to fuse to form a zygote
    • Zygote is allowed to develop for a week
    • Developed zygote is transferred to mothers body where it developed like other babies
• Embryo: Once zygote is formed it divides and redivides to form a group of cells. These groups furthers develops to form other body organs and tissues. Such a developing structure is called an embryo.
• Foetus: Stage of development of embryo where all body parts like head hands, legs, etc can be recognised is called foetus.
• Viviparous animals: Development of embryo takes place inside the mother’s body and then mother give birth to young one. E.g. Cow, dogs, etc
• Oviparous animals: Development of embryo takes place outside the mothers body in the egg. E.g. hen, birds, etc
• Asexual reproduction :
  • Budding: Asexual reproduction in which bud detaches from the parent body so as to form a new individual.
  • Binary fission: asexual reproduction in which parent cell body divides in two cells, each containing a daughter nuclei. Thus, parent cell divides to form two new organisms.
• Cloning: Process of making exact copy of cell, any living part or a complete organisms.