Human Reproduction Class 12 Notes

Reproduction is the process of giving birth to their young ones which are identical to their parents. As we all are aware of, the process of reproduction in humans is sexual reproduction, which involves internal fertilization by sexual intercourse.

Human Reproductive System

The Human Reproductive System mainly consists of:

  • The Male Reproductive System

The male reproductive system is located in the pelvis region and includes a pair of testes along with the accessory ducts, glands, and the external genitalia.

  • The Female Reproductive System

The female reproductive system is made up of the internal and external sex organs, which consists of a pair of ovaries and oviducts, uterus, cervix, vagina and the external genitalia located in the pelvic region. Along with the mammary glands, these female reproductive organs are integrated structurally and functionally to support the complete processes of reproduction including ovulation, fertilization, pregnancy, and the birth of a child.

Both the male and female reproductive systems play an important role in the process of reproduction. Other than these reproductive organs, there are sex hormones which are produced by the respective glands and are mainly involved in the development of secondary sexual characteristics and proper functioning of the reproductive tracts.

Process of Reproduction

The process of reproduction in all humans are carried out in various stages as mentioned below:

  • Pre-fertilization – Formation and the transfer of Gametes.
  • Fertilization- A sperm fertilizes the egg and the zygote is formed
  • Post-fertilization- The fertilized egg or zygote divides mitotically and develops into an embryo. This stage of reproduction is called as embryogenesis.

Duration and Stages of Pregnancy

Human gestation lasts for an average of 266 days or 38 weeks or 9 months and these intervals are called as trimesters.

  • 1st trimester (1st 3 months or week 1 – 12) – pre embryonic and embryonic development.
  • 2nd trimester (next 3 months: week 13 – 24) – The fetal development begins.
  • 3rd trimester (next 3 months: week 25 – birth) – At this stage baby continues to grow and mature.

Few Important Questions

  • What are the three stages of parturition?
  • What happens during spermatogenesis?
  • Describe the structure of a male reproductive system?
  • What is the role of sex hormones in the human reproductive system?
  • Explain in detail about the female reproductive system with a neat labeled diagram?

Learn more about human reproduction from the topics given below:


Practise This Question

Which of the following is an advantage of transgenic organisms?