Human Reproduction – Class 12 Biology Notes | CBSE NCERT Based

 📚 Chapter: Human Reproduction – Class 12 Biology Notes


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🔸 Introduction:

Human reproduction is sexual reproduction involving the fusion of male and female gametes. This chapter covers reproductive organs, gamete formation, menstrual cycle, fertilisation and pregnancy.


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🔹 1. Male Reproductive System

Primary organs: Testes (sperm production)

Accessory ducts: Epididymis, Vas deferens, Urethra

Glands: Seminal vesicles, Prostate, Bulbourethral

External genitalia: Penis

Spermatogenesis: Formation of sperm in seminiferous tubules

Hormone control: FSH, LH, Testosterone



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🔹 2. Female Reproductive System

Primary organs: Ovaries (ovum production)

Ducts: Fallopian tubes, Uterus, Cervix, Vagina

External genitalia: Vulva

Oogenesis: Formation of ovum

Hormone control: Estrogen, Progesterone, FSH, LH



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🔹 3. Menstrual Cycle

Average duration: 28 days

Phases:

1. Menstrual phase (1-5 days)


2. Follicular phase (6–13 days)


3. Ovulation (Day 14)


4. Luteal phase (15–28 days)



Controlled by hormones (FSH, LH, Estrogen, Progesterone)



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🔹 4. Fertilisation and Implantation

Fertilisation occurs in ampulla of fallopian tube

Zygote → Morula → Blastocyst

Implantation in uterine wall



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🔹 5. Pregnancy and Embryonic Development

Gestation period: 9 months (approx)

Placenta forms: nutrient & waste exchange

Important hormones: hCG, hPL, Relaxin, Estrogen, Progesterone



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🔹 6. Parturition and Lactation

Parturition: Childbirth, triggered by oxytocin

Lactation: Milk production by mammary glands

Hormone: Prolactin



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📌 Conclusion:

Human reproduction is a complex but beautifully regulated process. Hormones, organs and time cycles work together to ensure successful reproduction and child development.




















✍️ Written by: Shahid – Study with Shahid
🔗 Visit: https://shahidnotes12.blogspot.com







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