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SOLAR ECLIPSE 2025

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   Introduction to Solar Eclipses Solar eclipses are one of the most fascinating celestial events, capturing the curiosity of scientists, astronomers, and the general public alike. These occur when the Moon passes between the Earth and the Sun, either partially or completely obscuring the Sun's light. There are different types of solar eclipses: Total Solar Eclipse : The Moon completely covers the Sun. Partial Solar Eclipse : The Moon partially blocks the Sun, creating a crescent shape. Annular Solar Eclipse : The Moon covers the center of the Sun, leaving a ring-like appearance. Hybrid Solar Eclipse : A rare eclipse that transitions between total and annular phases. The Solar Eclipse of 2025 In 2025, two significant solar eclipses will occur: March 29, 2025 – A partial solar eclipse , visible in several parts of the world but not visible from India . September 21, 2025 – Another partial solar eclipse , with possible limited visibility in India. Key Details of the March 29, ...
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HUMAN REPRODUCTION REVISION NOTES NCERT HIGHLIGHTS

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  •  The male reproductive system includes testes, male sex accessory ducts, accessory glands, and external genitalia.

  • Testes have 250 compartments called testicular lobules, each containing one to three seminiferous tubules.

  • Spermatogonia and Sertoli cells line the seminiferous tubules, and Leydig cells outside the tubules produce androgens.

  • The female reproductive system includes ovaries, oviducts, uterus, vagina, external genitalia, and mammary glands.

  • Ovaries produce the female gamete (ovum) and ovarian hormones, and oviducts, uterus, and vagina are female accessory ducts.

  • The menstrual cycle is the reproductive cycle of female primates, induced by changes in pituitary and ovarian hormones.

  • Oogenesis is the process of the formation of mature female gametes.

  • Spermatogenesis results in the formation of sperms, which are transported by male sex accessory ducts.

  • Fertilization occurs when the sperm fertilizes the ovum, leading to the formation of a diploid zygote.

  • The presence of an X or Y chromosome in the sperm determines the sex of the embryo.

  • The zygote undergoes repeated mitotic division to form a blastocyst, which is implanted in the uterus, resulting in pregnancy.

  • After nine months of pregnancy, the fully developed fetus is ready for delivery.

  • The process of childbirth is called parturition, induced by a complex neuroendocrine mechanism involving cortisol, estrogens, and oxytocin.

  • Mammary glands differentiate during pregnancy and secrete milk after childbirth, which is fed to the newborn baby (lactation) during the initial few months of growth.



A diagrammatic sectional view of the male pelvis showing the reproductive system



Diagrammatic view of male reproductive system (part of testis is open to show inner details) 
A diagrammatic sectional view of the female reproductive system

A diagrammatic sectional view of the Mammary gland

A diagrammatic sectional view of a seminiferous tubule (enlarged)
Structure of a sperm

Diagrammatic Section view of ovary








Ovum surrounded by few sperms














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