ICSE Class 10 Biology: Reproduction in Humans — Notes 2026

Types of Reproduction

• Asexual: single parent, genetically identical offspring; e.g., binary fission, budding, vegetative propagation
• Sexual: two parents, gametes fuse → zygote; genetic variation in offspring
• Advantages of sexual reproduction: genetic variation → adaptability

Male Reproductive System

• Testes (in scrotum, 2–3°C below body): produce sperms and testosterone
• Epididymis: sperm maturation and storage; vas deferens: carries sperm to urethra
• Accessory glands: seminal vesicle (fructose), prostate gland (enzymes), Cowper's gland (lubricant)

Female Reproductive System

• Ovaries: produce eggs (ova) and hormones (oestrogen, progesterone)
• Fallopian tubes (oviducts): carry egg from ovary to uterus; fertilisation occurs here
• Uterus: site of implantation and fetal development; cervix connects to vagina

Gametogenesis

• Spermatogenesis: diploid spermatogonia → sperms (haploid) via meiosis; millions daily
• Oogenesis: diploid oogonia → one egg (haploid) per month; begins before birth, completed at fertilisation
• Sperm: small, motile, carries nuclear DNA in head; egg: large, non-motile, has food reserves

Menstrual Cycle

• 28-day cycle: menstruation (days 1–5), follicular phase (6–13), ovulation (day 14), luteal phase (15–28)
• FSH → Graafian follicle matures → oestrogen rises → LH surge → ovulation
• If no fertilisation: corpus luteum degenerates → progesterone falls → endometrium sheds (menstruation)

Fertilisation and Development

• Sperm penetrates egg in fallopian tube; acrosome reaction; cortical reaction prevents polyspermy
• Zygote → cleavage → morula → blastocyst → implantation in uterine wall (day 6–7)
• Placenta: exchange of nutrients, O₂, CO₂, waste between mother and fetus; secretes HCG (confirms pregnancy)

ICSE Exam — Reproduction

• Draw and label the female reproductive system
• Describe the role of FSH and LH in the menstrual cycle
• Define: zygote, embryo, fetus, placenta