Error Solutions Workbook
Zoology — Reproductive Health

• Five candidate factors.
• Four of them are the NCERT list; one is a control measure.

Which factors push the population up.

NCERT gives four reasons for the population explosion: a rapid decline in death rate, in maternal mortality rate and in infant mortality rate, together with an increase in the number of people in the reproductive age group. All four mean more people surviving and more people able to reproduce.

Raising the statutory marriageable age (18 for girls, 21 for boys) is listed in the same chapter as a measure to control growth — it delays childbearing and shortens the reproductive window. It belongs on the opposite side of the ledger.

1. Sort each factor by its arrow. Does it add people, or remove them?
2. A, B, C — fewer deaths → more people. In.
3. D — more people of reproductive age → more births. In.
4. E — later marriage → fewer births. Out; this is a control measure.
5. Answer: A, B, C and D only.

• Draw an up-arrow or a down-arrow beside every lettered statement before you read the options. Causes and cures are deliberately mixed in this chapter.
• An option that includes all the letters is almost never right when the list mixes causes with remedies — it is the standard over-inclusion bait.

• Four assisted reproductive technologies with definitions.
• The question asks for the pair that is wrong.

The single mismatched pair.

GIFT is Gamete Intra Fallopian Transfer: an ovum collected from a donor is transferred into the fallopian tube of another female who cannot produce ova but can provide a suitable environment for fertilisation and further development. Fertilisation happens inside the body — it is in vivo, not in vitro. That is the error.

The other three are correct as printed: ICSI injects a single sperm directly into the ovum; ZIFT transfers a zygote or early embryo (up to 8 blastomeres) into the fallopian tube; IUT transfers an embryo with more than 8 blastomeres into the uterus.

1. Underline the word incorrectly. You are hunting for the false one.
2. Expand each acronym. The expansion usually contains the answer: GIFT has “gamete” and “fallopian” in it, so nothing about it is in vitro.
3. Check the blastomere split. Up to 8 → ZIFT (tube). More than 8 → IUT (uterus). Both as printed.
4. Only GIFT is mismatched.

• GIFT = gametes, in the tube, in vivo. ZIFT = zygote, in the tube, after IVF. One letter apart, opposite fertilisation sites.
• 8 blastomeres is the dividing line between ZIFT and IUT. Memorise the number, not the sentence.

• Five dated events from the Reproductive Health chapter.

Their chronological order.

Anchor each event to its decade:

• D — family planning programmes initiated: 1951. India was the first country in the world to launch a national programme. Earliest by far.
• E — MTP legalised: the MTP Act, 1971.
• B — India near one billion: around 2000 (NCERT: about 1 billion at the turn of the century).
• A — world population about 7.2 billion: 2011 (6 billion in 2000, 7.2 billion by 2011).
• C — MTP (Amendment) Act: the most recent of the five.

1. Write a year beside every letter before looking at any arrow chain.
2. D 1951, E 1971, B 2000, A 2011, C latest.
3. Sort: D → E → B → A → C.
4. Match that chain to an option — do not try to check four chains one by one.

• The Act always comes before its Amendment. E must precede C in every correct chain — that one rule eliminates any option with C before E.
• India’s billion (2000) comes before the world’s 7.2 billion (2011). The option that was marked has these two swapped.
• Sorting your own list is faster and safer than validating theirs.

• Four features associated with sexually transmitted infections.
• The question asks for the one that is not an early symptom.

The feature that appears late, as a complication.

NCERT lists the early symptoms of most STIs as minor and easily ignored: itching, fluid discharge, slight pain and swellings in the genital region. Precisely because they are mild, infections often go unreported.

If untreated, they progress to complications: pelvic inflammatory disease (PID), abortions, still births, ectopic pregnancies, infertility, and in some cases cancer of the reproductive tract. PID is an outcome, not an opening sign.

1. Circle the word not.
2. Split the four into two boxes: minor local signs vs named disease states.
3. Itching, discharge, slight pain → all minor local signs, all early.
4. PID is a named disease of the upper tract → a complication. That is the answer.

• If an option is a disease with a name, it is a complication, not an early symptom. Works for PID, ectopic pregnancy and infertility alike.
• In “which is NOT” items, three options will belong to one obvious family. Find the family, and the outsider is the answer.

• Four claims about Saheli.

Which of them are true.

Saheli is the oral contraceptive developed at the CDRI, Lucknow. Its defining feature is that it is non-steroidal — it contains no hormone at all. That is exactly why NCERT highlights it: very few side effects and high contraceptive value, and it is a once-a-week pill rather than a daily one.

The progestogen–oestrogen combination describes the ordinary combined oral pill (Mala-D, Mala-N), taken daily for 21 days. Statement B has transplanted that description onto Saheli.

1. A — oral, for females. TRUE.
2. B — Saheli is non-steroidal, so no progestogen and no oestrogen. FALSE.
3. C — once a week. TRUE (this is its signature).
4. D — few side effects, high contraceptive value. TRUE.
5. A, C, D → option 3.

• “Saheli — non-steroidal, once a week, CDRI Lucknow.” Three facts, one line. Any statement giving Saheli a hormone is false.
• Daily pill = hormones. Weekly pill = no hormones. The frequency and the composition always travel together in this chapter.

• Five mechanisms drawn from across the contraception chapter.
• Only the ones belonging to oral pills may be selected.

The actions of the oral pill.

Oral pills work by three routes: they inhibit ovulation (no secondary oocyte released), they inhibit implantation, and they alter the quality of the cervical mucus so that sperm entry is prevented or retarded. Statements B, C and E are those three.

The other two belong to different methods. Increased phagocytosis of sperms in the uterus is how non-medicated IUDs such as the Lippes loop work. Blocking gamete transport through the fallopian tubes is tubectomy — a surgical method.

1. Name the owner of each mechanism before selecting anything.
2. A → IUD. D → sterilisation. Both out.
3. B, C, E → the three pill actions. In.
4. Answer: B, C and E only.

• Pill = ovulation, implantation, mucus. Three words. Anything mechanical or surgical is not the pill.
• Phagocytosis belongs to the IUD — it is the one mechanism the chapter mentions twice, which is why it is the favourite distractor here.
• Blocking a tube always means surgery or a device, never a hormone.

• A natural contraceptive method defined by abstaining on particular days.

The method (A) and the day range (B).

Periodic abstinence is the natural method in which a couple avoids coitus from day 10 to day 17 of the cycle, because ovulation is expected in that window and conception has a high chance. That window is called the fertile period.

In a 28-day cycle ovulation occurs around day 14. The window is drawn wide on both sides of day 14 to allow for sperm survival and for variation in the cycle.

Coitus interruptus is withdrawal before ejaculation — not a calendar method at all. Lactational amenorrhoea is the absence of the cycle during intense breast-feeding, up to about six months post-partum.

1. Fill blank A from the definition. “Avoid coitus on certain days” → periodic abstinence. That leaves options 1 and 4.
2. Fill blank B from ovulation. Ovulation ≈ day 14, so the window must contain day 14.
3. Days 1–5 are the menstrual days — the least fertile part of the cycle. Out.
4. Days 10–17 straddle day 14 → correct.

• Any fertile-window option that does not include day 14 is wrong. One check, done.
• Days 1–5 are bleeding days. Abstaining then would be pointless as contraception — a sanity check you can run in two seconds.

• Multiload 375 — an intrauterine device.

Its mechanism of action.

IUDs come in three families, and NCERT names examples of each:

• Non-medicated: Lippes loop — increases phagocytosis of sperms in the uterus.
• Copper-releasing: CuT, Cu7, Multiload 375 — the released Cu²⁺ ions suppress sperm motility and the fertilising capacity of sperms.
• Hormone-releasing: Progestasert, LNG-20 — make the uterus unsuitable for implantation and the cervix hostile to sperms.

The number 375 refers to the surface area of copper on the device — the name itself tells you which family it belongs to.

1. Place the device in its family. Multiload 375 → copper-releasing.
2. Recall that family’s mechanism. Cu²⁺ → suppresses sperm motility and fertilising capacity.
3. Reject the others by owner: hostile cervix → hormonal IUD; blocking oviducts → tubectomy; inhibiting the LH surge → oral pill.

• Learn the three IUD families with one example each. Every IUD question in NEET is answered by naming the family first.
• CuT, Cu7, Multiload 375 — all copper. The word or number in the name is the clue.

• Ovaries work → ova are available.
• Uterus is receptive → it can carry an embryo.
• Both tubes blocked → nothing can be placed in, or pass through, a tube.
• Semen normal → no need to inject a single sperm.

The correct pairing of fertilisation technique and transfer route.

An ART answer is always two decisions. How is the egg fertilised? — ordinary IVF if the sperm are normal, ICSI only if the sperm cannot penetrate the ovum. Where is the product put back? — ZIFT into the fallopian tube, IUT into the uterus.

Here the tubes are blocked, which rules out every tube-based transfer, and the sperm are normal, which makes ICSI unnecessary. So: fertilise in the dish (IVF), transfer into the uterus (IUT).

1. Decide the fertilisation step from the semen report. Normal → IVF, not ICSI. Options 3 and 4 out.
2. Decide the transfer route from the tubes. Blocked → the embryo cannot be placed in a tube. ZIFT out.
3. What remains is IVF followed by IUT.

• Two clues, two decisions. Sperm quality picks IVF vs ICSI; tube patency picks IUT vs ZIFT. Every clinical ART question in NEET is built on exactly this pair.
• Blocked tubes → the uterus is the only destination.
• Don’t reach for ICSI because the case sounds serious. ICSI is a sperm solution, and the sperm here are fine.

• Two claims about hormonal injections and implants.

The truth value of each statement.

NCERT states that progestogens alone, or in combination with oestrogen, can be used by females as injections or implants. The lead hormone is the progestogen. Statement I has swapped the two, putting oestrogen in the lead and implying oestrogen alone may be given — that is not what is taught.

On duration: injections and implants work like oral pills, but their effective period is much longer — that is their whole advantage over a pill you must remember daily. Statement II says shorter, so it is false.

1. Judge Statement I alone. The hormone named first should be progestogen → FALSE.
2. Judge Statement II alone. One word — shorter — decides it. It should be longer → FALSE.
3. Only now read the four options and pick the one that says false–false.

• Longer-acting is the entire point of an injection or implant. Any statement calling them shorter-acting is false on sight.
• Progestogen leads; oestrogen assists. In this chapter progestogen is named first every time.
• For two-statement items, write T or F beside each statement on the paper, then match. This is the third question on these sheets lost to skipping that step.

• The pregnancy is in its third month — that is, weeks 9 to 12.
• A legally permitted ground already exists.

The minimum number of registered medical practitioners whose opinion is required.

The law works in gestational brackets, and the number of opinions rises as the pregnancy advances. Under the original MTP Act, 1971 the split was up to 12 weeks → one practitioner and 12–20 weeks → two. The Amendment widened the brackets — up to 20 weeks → one and 20–24 weeks → two — but it did not change what happens early.

The third month falls inside the first 12 weeks under either version, so the answer is one registered medical practitioner and does not depend on which version you were taught.

1. Convert months to weeks. Third month = weeks 9–12.
2. Place it in a bracket. That is inside the earliest bracket on any version of the Act.
3. Read off the number: one.

• Always convert months into weeks first. The statute is written in weeks and the question in months — that gap is the difficulty, not the law.
• The number of opinions never exceeds two in this Act, so options 3 and 4 can go immediately.
• MTPs are advised in the first trimester and are much safer there — the light requirement early on is consistent with that.

• The IVF–ET (test-tube baby) programme.
• The question asks for all possible sources on both sides.

The complete set of permitted gamete sources.

In IVF–ET, ova from the wife or a female donor and sperms from the husband or a male donor are collected and induced to form a zygote under simulated laboratory conditions. The symmetry is deliberate: the programme exists precisely for couples where either partner cannot supply a viable gamete.

The zygote or early embryo (up to 8 blastomeres) may then be transferred into the fallopian tube (ZIFT), or an embryo of more than 8 blastomeres into the uterus (IUT).

1. Ask whether donation is allowed on the sperm side. Yes — husband or male donor.
2. Ask the same on the ovum side. Yes — wife or female donor.
3. Both open → only option 3 has both.
4. Option 4 fails because the couple’s own gametes are the first choice, not excluded.

• The sentence is symmetric. Whatever is true for sperms is true for ova. An option that opens one side and closes the other is wrong by shape alone.
• The word “all possible” in the stem means you are looking for the widest correct option, not the most typical case.

1. Before choosing a mechanism, name the method it belongs to. Every one of Q152, Q161 and Q165 was a true fact filed under the wrong device.
2. In select-the-set questions, give the last statement more scrutiny than the first — that is where the reversal hides (Q142's option E, Q161's option A).
3. Circle not, incorrectly and except, then write the word FALSE in the margin before reading option 1.