Last Minute Revision Checklist!!!
Grade 12 Biology — Reproduction & Development
MUST-KNOW FACTS (High-Yield)
GnRH → FSH & LH → gonads → sex hormones
Negative feedback controls hormone levels
LH surge causes ovulation
Progesterone drop causes menstruation
Fertilization occurs in the Fallopian tube
Cleavage = cell division with NO growth
Implantation occurs in the uterus
hCG maintains corpus luteum early in pregnancy
Placenta later produces estrogen & progesterone
Birth uses POSITIVE feedback (oxytocin)
Prolactin produces milk; oxytocin releases milk
Teratogens cross the placenta (alcohol = FASD)
SRY gene on Y chromosome → testes → testosterone
IVF = fertilization outside the body
MUST-USE KEYWORDS (Marks Live Here)
Use these exact words:
GnRH, FSH, LH
Negative feedback / Positive feedback
Estrogen, Progesterone, Testosterone
Ovulation, Corpus luteum
Fertilization, Cleavage, Blastocyst, Implantation
hCG, Placenta
Oxytocin, Prolactin
Teratogen, FASD
SRY gene
IVF
DIAGRAMS YOU SHOULD REDRAW
Male hormone pathway (GnRH →
FSH/LH →
testes)
Female hormone cycle (FSH →estrogen →
LH surge → progesterone)
Menstrual cycle timeline (hormone graph)
Sperm pathway
Egg pathway
Blastocyst + implantation
Placenta & umbilical cord
Germ layers (ectoderm / mesoderm / endoderm)
,COMMON MISTAKES TO AVOID
❌ FSH produces testosterone
❌ Fertilization happens in uterus
❌ Cleavage increases size
❌ Placenta works immediately
❌ Birth uses negative feedback
❌ Oxytocin produces milk
❌ Placenta blocks all toxins
❌ Chromosomes alone determine sex
❌ IVF = sperm injection into uterus
Reproduction & Development – Common
Exam Mistakes & Corrections
1. Hormonal Regulation (Male & Female)
❌ Mistake
“FSH causes testosterone production.”
Why students make it
Both FSH and LH are released together
Students memorize hormones without linking to target cells
Marks typically lost
2–3 marks (wrong hormone → wrong pathway)
✅ Correct exam-style answer
LH stimulates interstitial (Leydig) cells in the testes to produce testosterone, while FSH
stimulates sperm production in the seminiferous tubules.
2. Menstrual Cycle
❌ Mistake
“Menstruation happens because ovulation occurs.”
Why students make it
Confusing events with causes
, Memorizing phases without hormone logic
Marks typically lost
3–4 marks (cause-and-effect error)
✅ Correct exam-style answer
Menstruation occurs when estrogen and progesterone levels drop due to the breakdown of
the corpus luteum, causing the endometrium to shed.
3. Male Reproductive System
❌ Mistake
“Sperm mature in the testes.”
Why students make it
Production and maturation happen close together
Diagram labels are memorized, not understood
Marks typically lost
1–2 marks
✅ Correct exam-style answer
Sperm are produced in the seminiferous tubules of the testes but mature and gain motility in
the epididymis.
4. Female Reproductive System
❌ Mistake
“Fertilization happens in the uterus.”
Why students make it
Uterus is associated with pregnancy
Location-based questions cause panic
Marks typically lost
2–3 marks (location error)
✅ Correct exam-style answer
Grade 12 Biology — Reproduction & Development
MUST-KNOW FACTS (High-Yield)
GnRH → FSH & LH → gonads → sex hormones
Negative feedback controls hormone levels
LH surge causes ovulation
Progesterone drop causes menstruation
Fertilization occurs in the Fallopian tube
Cleavage = cell division with NO growth
Implantation occurs in the uterus
hCG maintains corpus luteum early in pregnancy
Placenta later produces estrogen & progesterone
Birth uses POSITIVE feedback (oxytocin)
Prolactin produces milk; oxytocin releases milk
Teratogens cross the placenta (alcohol = FASD)
SRY gene on Y chromosome → testes → testosterone
IVF = fertilization outside the body
MUST-USE KEYWORDS (Marks Live Here)
Use these exact words:
GnRH, FSH, LH
Negative feedback / Positive feedback
Estrogen, Progesterone, Testosterone
Ovulation, Corpus luteum
Fertilization, Cleavage, Blastocyst, Implantation
hCG, Placenta
Oxytocin, Prolactin
Teratogen, FASD
SRY gene
IVF
DIAGRAMS YOU SHOULD REDRAW
Male hormone pathway (GnRH →
FSH/LH →
testes)
Female hormone cycle (FSH →estrogen →
LH surge → progesterone)
Menstrual cycle timeline (hormone graph)
Sperm pathway
Egg pathway
Blastocyst + implantation
Placenta & umbilical cord
Germ layers (ectoderm / mesoderm / endoderm)
,COMMON MISTAKES TO AVOID
❌ FSH produces testosterone
❌ Fertilization happens in uterus
❌ Cleavage increases size
❌ Placenta works immediately
❌ Birth uses negative feedback
❌ Oxytocin produces milk
❌ Placenta blocks all toxins
❌ Chromosomes alone determine sex
❌ IVF = sperm injection into uterus
Reproduction & Development – Common
Exam Mistakes & Corrections
1. Hormonal Regulation (Male & Female)
❌ Mistake
“FSH causes testosterone production.”
Why students make it
Both FSH and LH are released together
Students memorize hormones without linking to target cells
Marks typically lost
2–3 marks (wrong hormone → wrong pathway)
✅ Correct exam-style answer
LH stimulates interstitial (Leydig) cells in the testes to produce testosterone, while FSH
stimulates sperm production in the seminiferous tubules.
2. Menstrual Cycle
❌ Mistake
“Menstruation happens because ovulation occurs.”
Why students make it
Confusing events with causes
, Memorizing phases without hormone logic
Marks typically lost
3–4 marks (cause-and-effect error)
✅ Correct exam-style answer
Menstruation occurs when estrogen and progesterone levels drop due to the breakdown of
the corpus luteum, causing the endometrium to shed.
3. Male Reproductive System
❌ Mistake
“Sperm mature in the testes.”
Why students make it
Production and maturation happen close together
Diagram labels are memorized, not understood
Marks typically lost
1–2 marks
✅ Correct exam-style answer
Sperm are produced in the seminiferous tubules of the testes but mature and gain motility in
the epididymis.
4. Female Reproductive System
❌ Mistake
“Fertilization happens in the uterus.”
Why students make it
Uterus is associated with pregnancy
Location-based questions cause panic
Marks typically lost
2–3 marks (location error)
✅ Correct exam-style answer
