Xam Idea Class 12 Biology Chapter 3 Solutions: Human Reproduction

Xam Idea Class 12 Biology Solutions Chapter 3 ‘Human Reproduction’ discusses the reproductive system of humans (male and female) and various reproductive organs in the human body. The reproductive system of male and females have a major difference and how they function differently is explained in this chapter of Xam Idea solutions. Our solutions have covered all the topics like the male reproductive system, the female reproductive system, gametogenesis, menstrual cycle, fertilization and implantation, pregnancy and embryonic development, parturition and lactation.

Xam Idea Class 12 Biology Solutions include answers to all 169 exercise questions. They are designed as per the latest CBSE Class 12 syllabus. Xam Idea Class 12 Biology Solutions will help in making your fundamentals of the chapter strong. They would guide you to prepare for your CBSE Class 12 board exams thoroughly. We have included answers to all the basic concepts of the chapters, higher-order thinking skill (HOTS) problems, and for previous years CBSE board exams in our Xam Idea solutions.

Our Xam Idea Class 12 solutions emphasis on the theoretical aspects of the chapter that can help you in understanding and remembering the concepts in-depth. Our solutions are well-designed and well-organized by the finest academic experts and are best suited for scoring high in CBSE board exams. You can also use our solutions for Xam Idea Class 12 Biology chapters as revision notes during exams.

Important topics for Xam Idea Class 12 Biology Solutions Chapter 3: Human Reproduction

Humans can reproduce sexually. The reproductive process of humans includes the formation of gametes, transferring of sperms (in the male) into the female genital tract, an amalgamation of male and female gametes which forms a zygote. This process further includes the formation and development of blastocyst, embryonic development, and delivery of the baby.

  • The male reproductive system: It has primary sex organs and secondary sex organs. The primary sex organs have a pair of testes suspended in a scrotum. The secondary sex organs have a pair of ducts each differentiated into an epididymis, a vas deferens, and an ejaculatory duct. A male urethra passing through an erectile penis. There are three types of Glands – a pair of seminal vesicles, a prostate gland, and a pair of Cowper’s glands.
  •   The female reproductive system: It has primary sex organs and secondary sex organs. The primary sex organs have a pair of ovaries. The secondary sex organs have a pair of fallopian tubes, a uterus, and a vagina. Ovaries in the female reproductive system produce female gametes called ova.
  • Phases of embryonic development: Embryonic development involves following dynamic changes and identifiable processes.

Gametogenesis: They are present in the reproductive organ called gonads of a human being. The gametes called sperms and ova are formed by the process in which cells undergo meiosis. It is of two types:

Spermatogenesis: Formation of sperm.                   

Oogenesis: Formation of ova

Fertilization: It involves the fusion of haploid male and female gametes to form a diploid zygote. Karyogamy is the fusion of gametic pronuclei while amphimixis means the mixing of two sets of chromosomes of two gametes.

Cleavage: Cleavage is the process in which the rapid mitotic division of zygote forms a single-layered hollow spherical larva called the blastula. This formation is called the blastulation.

Implantation: The process of attachment of the blastocyst (mammalian blastula) on the endometrium of the uterus is called implantation.

Gastrulation: Gastrula has 3 primary layers and the process of forming gastrula from blastula is called Gastrulation. The cells move into the interior of the embryo during gastrulation.

Organogenesis: When a specific organ system is formed from the three primary germ layers of gastrula and it also contains the morphogenesis and differentiation then it is called Organogenesis.


  • Significance of fertilization:


It provides the stimulus for the egg to complete its maturation.

It activates the ovum to develop into a new individual by repeated mitotic division.

Fertilization restores the diploid number of chromosomes (46 in man) in the zygote by adding a male’s haploid set of chromosomes.

It makes the egg more active metabolically.

It combines the character of two parents and introduces variations. So help in evolution.

Sex chromosomes of sperm are either X or Y and help in sex determination.

Fertilization membrane formed after sperm entry checks the entry of additional sperms.

The copulation path sets the axis of division.

  •   Menstrual Cycle:

Menstruation occurs in humans, apes, and old-world monkeys.

The bleeding from the uterus of adult females at intervals of one lunar month is menstruation.

The beginning of menstruation or first menstruation is called menarche.

The beginning of menstruation varies. It usually occurs between 12 and 15 years.

The cycle of events starting from one menstruation till the next one is called Menstrual Cycle.

Menstruation is repeated at an average interval of about 28/29 days in adult females.

One ovum is released (ovulation) during the middle of each menstrual cycle.

It is regulated by certain hormones, some of which are secreted by the pituitary gland.

The pituitary gland is stimulated by releasing factors produced in the hypothalamus.

The hormones produced by the pituitary gland influence the ovaries. The hormones secreted by the ovaries affect the walls of the uterus.

Exercise Discussion for Xam Idea Class 12 Biology Solutions Chapter 3: Human Reproduction

Chapter 12 Human Reproduction has a total of 169 solved problems in it. The problems are categorized into 4 parts: they are very short question answers, short question answers part I, short question answers part II, long question answers. Each category is further divided into two parts: PYQ (past years questions) and OIQ (objective inventory questionnaires).

Very Short Question Answers 

  • This section consists of a total of 43 questions out of which 12 questions fall under the PYQ section and the rest 30 questions fall under the OIQ section. 
  • Very short question answers section covers very simple and direct questions like a definition or give a reason or explain the functions of organs. Questions are based on topics like the tissues of the cell, menstrual cycle, endometrium, corona radiata, and zygote are discussed in this section.

Short Question Answers part I & II

  • Part I consists of a total of 56 questions from which 27 questions belong to the PYQ category and 29 questions belong to the OIQ category. 
  • Part II consists of a total of 24 questions from which 17 questions belong to the PYQ and 7 questions belong to the OIQ. 
  • The complexity of the question asked in this section increases as compared to a very short QA. 
  • Questions are based on topics like Corpus luteum, menstrual cycle, menopause, hormonal changes, spermatogenesis, male gametes, a human embryo, and ovulation are asked in this section.

Long Question Answers

  • It consists of a total of 46 questions from which 34 questions belong to the PYQ category and 12 questions belong to the OIQ category. 
  • It covers the most complex and twisted questions of the chapter. Questions covered under this section are: the ovaries effect, influence of hormones, gametogenesis, seminal plasma, reproductive system, accessory gland, human fertilization, and human ovum.

Why Use Xam Idea Class 12 Biology Solutions Chapter 3: Human Reproduction by Instasolv?

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