Main Points

Reproduction

  • The process by which an organism creates its own like is called reproduction.
  • DNA replication is a high precision process but like all other biogeochemical processes, it may have certain discrepancies.
  • Some minor variations always occur during DNA replication. This is the reason, no two individuals look alike.
  • When reproduction involves a single parent, it is called asexual reproduction.
  • The unicellular organisms reproduce by fission. There are two types of fission, viz. binary fission and multiple fission.
  • Reproduction by fragmentation is seen in multicellular organisms with simple body organization, i.e. in organisms without various types of tissues.
  • When a new plant is produced from a vegetative part, the process is called vegetative propagation. Vegetative propagation can take place by root, stem and leaf.
  • When two parents are involved in reproduction, it is called sexual reproduction. Gamete formation is an integral part of sexual reproduction.
  • Conventionally, the bigger germ cell is called the female gamete while the smaller germ cell is called the male gamete. The stored food in the female gamete provides nutrition to the developing zygote.
  • Fusion of male and female gametes is called fertilization. The product of fertilization is called zygote.
  • After fertilization, ovary grows rapidly to become a fruit. Sepals, petals, stamens, style and stigma usually shrivel and fall off.
  • The period when sexual or reproductive maturity takes place is called adolescence. This period is marked by various significant changes at physiological as well as at psychological level.
  • The male reproductive system is composed of a pair of testes, vas deferens, seminal vesicle and penis.
  • The female reproductive system is composed of a pair of ovaries, fallopian tubes, a uterus and a vagina.
  • The embryo gets embedded in the wall of the uterus. This process is called implantation. Pregnancy starts only after implantation.
  • Reproductive Health covers the aspect of physical, mental and societal well being.
  • Methods to prevent pregnancy are called contraception or birth control. These methods can be divided into three categories, viz. barrier methods, intrauterine devices, hormonal methods and surgical methods.

These main points are highly helpful for last minute preparation for examination. You can glance through them while going for examination. You can view them in the school bus, in car, in elevator, etc.