NEET Biology: Human Reproduction One Shot Notes 2027 | Class 12 Chapter 2

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I am a  NEET Dropper. Today I'm sharing Complete Notes of Human Reproduction - Class 12 Biology Chapter 2. This is the most scoring chapter in NEET.

**NEET PYQ Trend Last 5 Years:**

2022: 4 Questions

2023: 3 Questions  

2024: 5 Questions

2025: 3 Questions

2026: 3 Questions Expected

**Means 3-5 Questions fixed every year from this chapter.**

**NEET 2027 One Shot Topics:**

**1. Male Reproductive System**

- **Testes**: Produces Sperms + Testosterone hormone

- **NCERT Line**: "Testes are situated outside abdominal cavity within scrotum because sperm formation requires 2-2.5°C lower temperature than body"

- **Spermatogenesis**: Spermatogonia → Primary spermatocyte → Secondary spermatocyte → Spermatid → Spermatozoa

- **Semen**: Sperms + Secretions of Seminal vesicle + Prostate + Bulbourethral gland

**2. Female Reproductive System**

- **Ovary**: Produces Ovum + Estrogen + Progesterone 

- **Oogenesis**: Oogonia → Primary oocyte → Secondary oocyte → Ovum

- **Fallopian Tube**: Fertilization occurs here at Ampullary-Isthmic junction

- **Uterus**: Site of implantation. Has 3 layers - Perimetrium, Myometrium, Endometrium

**3. Menstrual Cycle - 28 Days**

Day 1-5: Menstrual Phase → Endometrium sheds

Day 6-13: Follicular Phase → FSH rises, Estrogen increases

Day 14: Ovulation → LH Surge, Ovum released

Day 15-28: Luteal Phase → Corpus Luteum secretes Progesterone

**Corpus Luteum** = If no fertilization, it degenerates → Menstruation starts

**4. Fertilization & Pregnancy**

- **Fertilization**: Only Head + Middle piece of sperm enters ovum

- **Cleavage**: Zygote → Morula → Blastocyst → Implantation in uterus

- **Pregnancy**: 40 weeks = 280 days = 3 Trimesters

- **Placenta**: Secretes HCG, HPL, Estrogen, Progesterone. Acts as endocrine gland

**5. Parturition & Lactation**

- **Parturition**: Induced by Oxytocin from Pituitary + Cortisol from Fetal adrenal

- **Colostrum**: First milk, rich in Antibodies IgA - very important for baby

**Most Repeated NEET PYQs:**

Q1. Corpus luteum secretes? → **Progesterone**

Q2. Which accessory gland is absent in male? → **Bartholin gland**

Q3. How many mitochondria in sperm? → **50-75 in middle piece**

Q4. Site of fertilization? → **Ampullary-Isthmic junction of fallopian tube**

Q5. Hormone for milk ejection? → **Oxytocin**, for milk production? → **Prolactin**

Daily NCERT notes + PYQ for NEET 2027 Free PDF