The NEET trap in reproductive health is confusing which STD is caused by which pathogen, confusing viral vs. bacterial STDs (treatment implications), and mixing up infertility causes between male and female factors.
Sexually Transmitted Diseases (STDs) / Sexually Transmitted Infections (STIs):
NCERT Class 12 Biology Chapter 4 (Reproductive Health), page 56 onwards, categorises STDs by causative agent:
Key distinction for NEET: bacterial STDs are curable with antibiotics; viral STDs (HIV, herpes, hepatitis B, HPV) are incurable — only manageable.
Infertility:
Infertility is the inability to conceive after one year of unprotected intercourse. Causes include — male: low sperm count, abnormal morphology, erectile dysfunction; female: tubal blockage, anovulation, endometriosis, uterine anomalies. Both partners must be evaluated.
Assisted Reproductive Technologies (ART): IVF (in vitro fertilisation), ZIFT (zygote intrafallopian transfer — zygote up to 8 blastomeres placed in fallopian tube), GIFT (gamete intrafallopian transfer — ovum from donor + sperm placed in tube of female who cannot produce ova but can provide conditions for fertilisation and development), ICSI (intracytoplasmic sperm injection — for low sperm count), AI (artificial insemination — semen collected and introduced into vagina/uterus).
Watch-out: ZIFT transfers a zygote/early embryo into the fallopian tube; IUT (intra-uterine transfer) transfers embryos with >8 blastomeres into the uterus. Don't swap these.
Select an option to see the explanation. Wrong answers show why your choice was tempting — and name the exact trap it exploits.
Which of the following STDs is caused by a protozoan?
Which of the following STDs is incurable and can only be managed symptomatically?
In GIFT (Gamete Intra-Fallopian Transfer), what is transferred into the fallopian tube?
A couple has been infertile for 2 years. The male partner has extremely low sperm count but sperm morphology is normal. Which ART is most directly suited?
A patient presents with painless ulcer on genitalia (primary stage), followed by skin rashes and mucous membrane lesions. Which pathogen is most likely responsible?
In ZIFT, the embryo is transferred into the fallopian tube at which developmental stage?
A student claims that since hepatitis B is sexually transmitted, it must be a bacterial disease curable with antibiotics. What is the fundamental error in this reasoning?
A woman cannot produce ova but her uterine environment is healthy. Her husband has normal semen parameters. An ovum is collected from a donor. Which sequence of ART procedures would be most appropriate?
Given
A couple has been trying to conceive for 18 months without success. Investigation reveals: the wife ovulates normally, fallopian tubes are patent, uterine lining is healthy. The husband's semen analysis shows sperm count of 5 million/mL (normal: ≥15 million/mL) with 80% abnormal morphology.
Required
Identify the most appropriate ART and justify why other options are less suitable.
Concept
ART selection depends on identifying the limiting factor. Male factor infertility with severely low sperm count + poor morphology requires direct sperm-ovum intervention rather than relying on natural sperm-ovum interaction.
Relevant facts (not formulas)
- AI requires adequate sperm count for natural fertilisation in the tract. - IVF requires sperm to penetrate the ovum in vitro — still problematic with very low count + abnormal morphology. - ICSI bypasses all sperm motility/morphology barriers by direct injection of a single morphologically-selected sperm into the oocyte. - GIFT/ZIFT require in-vivo or near-in-vivo fertilisation — ineffective with severe male factor.
Analysis
- Wife: normal ovulation, patent tubes, healthy endometrium → female factors are not limiting. - Husband: 5 million/mL (below WHO threshold of 15 million/mL) + 80% abnormal morphology → severe oligoasthenoteratozoospermia (OAT syndrome). - The combination of low count AND poor morphology means even IVF (which requires some sperm to find and penetrate the ovum in a dish) may fail.
Conclusion
ICSI is the most appropriate choice. A single viable sperm is selected by the embryologist (bypassing count and morphology issues) and directly injected into the wife's retrieved oocyte. The resulting embryo can then be transferred to her uterus (she has a healthy uterine environment).
Final answer
**ICSI (Intracytoplasmic Sperm Injection)** — indicated for severe male factor infertility where sperm count and morphology preclude natural or even standard IVF fertilisation.
Common trap
Confusing ICSI with standard IVF: students assume "test-tube baby" (IVF) covers all infertility. IVF still requires sperm to penetrate the ovum in vitro — with 5 million/mL and 80% abnormal morphology, this is unreliable. ICSI specifically addresses this gap. Also: confusing GIFT applicability. GIFT is for females who cannot produce ova (anovulatory) but have healthy tubes — it does NOT address male factor.
Similar NEET-style question
"A couple is infertile due to the male partner's azoospermia (zero sperm in ejaculate). Which ART option is NOT possible using the husband's own gametes?" Answer: None of the standard ARTs work with zero sperm in ejaculate; testicular sperm extraction (TESE) + ICSI or donor sperm would be required. ---
STDs: gonorrhoea, syphilis, chlamydia, trichomoniasis, genital herpes, HPV (genital warts), HIV/AIDS. Infertility: 25% male factor, 25% female, 50% combined. ART covers IVF, ZIFT, GIFT.
-- NCERT Class 12 Biology, Ch. 3, p. 56These are the exact patterns that cause wrong answers in NEET. Each trap includes when it triggers and how to avoid it.
Category: Similar Terms
Hormonal: pills, implants. Barrier: condom, diaphragm. IUD: Cu releasing (CuT), hormonal (LNG-20). Surgical: vasectomy/tubectomy.
Question asks which category a specific method falls in.
Map by mechanism: hormone → pill/implant; physical block → barrier; uterine → IUD; permanent → surgical.
Category: Negative Marking
Fertilisation in ampulla; cleavage during journey; implantation occurs ~6-7 days after fertilisation in uterine endometrium.
Question on day of implantation, location of fertilisation.
Fertilisation = ampulla. Implantation = day 6-7 post-fertilisation in uterus.
Category: Similar Terms
FSH dominant follicular phase; LH surge triggers ovulation Day 14; progesterone dominant in luteal phase.
Question gives day or phase and asks dominant hormone.
Follicular = FSH. Day 14 = LH peak. Luteal = progesterone (corpus luteum).
Category: Similar Terms
Spermatogenesis: 1 spermatogonium → 4 sperm (all functional). Oogenesis: 1 oogonium → 1 functional ovum + 3 polar bodies.
Question on number of functional gametes per primary cell.
Sperm: 4. Ovum: 1 (with 3 polar bodies discarded).
Root cause: term confusion
Oogenesis yields ONLY 1 functional ovum + 3 (or 1 + 2) polar bodies that degenerate. Asymmetric cytokinesis preserves cytoplasm in the egg.
Root cause: concept gap
IUD mechanisms vary: copper IUDs (CuT) increase phagocytosis of sperm; hormonal IUDs (Mirena/LNG-20) thicken cervical mucus + suppress endometrium. Both reduce implantation.
Root cause: concept gap
Primary oocyte arrests in prophase I (until puberty). Secondary oocyte arrests in metaphase II (until fertilisation). Meiosis II only completes if sperm enters.
Root cause: term confusion
Progesterone MAINTAINS pregnancy; falls before parturition. Oxytocin (positive feedback) drives uterine contractions. Foetal cortisol triggers cascade.
Root cause: term confusion
hCG = human Chorionic Gonadotropin — placenta. LH/FSH = anterior pituitary. hCG maintains corpus luteum during early pregnancy.
Root cause: term confusion
Spermatogenesis cycle = ~64 days in humans. Spermatozoa storage in epididymis ~20-30 days more. Meiosis itself takes ~24 days.
48 questions from NEET 2020, 2021, 2022, 2023, 2024, 2025. Answers verified against NTA official keys.
The first menstruation is called :
Identify the correct description about the given figure:
Which of the following is not a component of Fallopian tube?
Which of the following is not a natural/traditional contraceptive method?
Identify the correct option (A), (B), (C), (D) with respect to spermatogenesis.
Large, colourful, fragrant flowers with nectar are seen in
What is the function of tassels in the corn cob?
Identify the incorrect statement related to Pollination :
Which part of the fruit, labelled in the given figure makes it a false fruit?
Lippe’s loop is a type of contraceptive used as:
At which stage of life the oogenesis process is initiated?
In which of the following animals, digestive tract has additional chambers like crop and gizzard?
Which of the following is not the function of conducting part of respiratory system?
Which of the following statements of incorrect? 148. Match List-I with List-II.
ÁmÃËÿ∑§ • «U∑§ ∑§Ê •œ¸‚ÍòÊË Áfl÷Ê¡Ÿ ¬Íáʸ „Ê ÃÊ „Ò —
•h¸ •œÊ flÃ˸ • «UʇÊÿ Á∑§‚◊ ¬ÊÿÊ ¡ÊÃÊ „Ò? 122. The ovary is half inferior in :
Recurring question shapes from past papers. Each pattern shows why wrong options look tempting.
similar term confusion
Biology relies on precise terminology; close terms tempt selection.
Test yourself on this topic with real past-paper questions:
Practice this topic →Get a structured 30-day study plan and a complete formula booklet — delivered to your inbox instantly.