Q12: What is Oogenesis? Give a Brief Account of Oogenesis.
Answer:
The process of formation of a mature female gamete (ovum) is called oogenesis. It occurs in the ovaries of the female reproductive system. Oogenesis is a discontinuous process it begins before birth, stops in mid-process & only resumes after menarche. It occurs in three phases: Multiplicative phase (formation of oogonia mitotically from the primary germ cells), Growth phase (growth of oogonia into primary oocyte) & Maturation phase (formation of mature ova from primary oocyte through meiosis). The maturation phase produces two haploid cells – The larger one called the secondary oocyte & the smaller one called the polar body (1st polar body). Meiosis II of secondary oocyte results in the formation of a functional egg or ovum and a second polar body: The first polar body may also divide to form two polar bodies of equal sizes which do not take part in reproduction & ultimately degenerates. The first maturation division may be completed in the ovaries just before ovulation, but the second one (Final) is completed outside the ovary after fertilization. The secondary oocyte is a female gamete in which the 1st meiotic division is completed & second meiotic division (Metaphase stage) has begun. The egg is released at the secondary oocyte stage under the effect of LH.
For More Information Read: What is Oogenesis?
NCERT Solutions for Class 12 Chapter 2 Human Reproduction
As per the revised curriculum of CBSE Syllabus 2023-24, this chapter, previously known as Chapter 3, has now been renumbered as Chapter 2. Stay updated with the latest changes in the curriculum.
NCERT Solutions for Class 12 Chapter 2 Human Reproduction is all about the process of sexual reproduction among humans. This chapter of Class 12 talks about the female reproductive system and the male reproductive system in detail. The NCERT Solutions for this chapter are prepared by our Top Biology Experts to take care of all important topics that might be asked in the upcoming CBSE Class 12 Board examination 2024. So, students can also refer to these solutions for their final examination preparation.
This Class 12 Biology Chapter 2 Human Reproduction NCERT Solutions are carefully developed using easy-to-understand language while adhering to the guidelines for solving NCERT Solutions for Class 12. Working through these solutions can be highly beneficial for students in their board exams, as well as in preparing for future competitive Exams.
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Class 12 |
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Text and Image |
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Academic Year |
2023-24 |
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English |
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Chapter Wise and Solution Wise |