Reproduction in Plants, and Reproductive Health

• Triple fusion: one male gamete fuses with the two polar nuclei of the central cell.

What the central cell becomes.

Double fertilisation has two halves and they must be kept apart. Syngamy gives the zygote, which becomes the embryo. Triple fusion involves the central cell, and afterwards that cell is called the primary endosperm cell. Its nucleus is the primary endosperm nucleus — a part of the cell, not the cell itself.

1. The central cell contains the two polar nuclei.
2. One male gamete fuses with them — three nuclei in all, hence triple fusion.
3. The cell is now triploid and is called the primary endosperm cell (PEC).
4. Its nucleus is the primary endosperm nucleus (PEN). The question asks about the cell, so PEC is the answer.
5. The PEC later divides to form the endosperm.

• A longitudinal section of a maize (monocot) grain.
• Labels A to G run from the top of the grain to the bottom.

Which pair of labels is correct.

A monocot embryo has two protective sheaths, one at each end, and their names tell you which is which. Coleoptile covers the shoot (the ptile end, upper); coleorrhiza covers the root (the rhiza end, lower). “Coleo-” simply means sheath. So the top label is the coleoptile and the bottom one is the coleorrhiza.

1. Read the labels in order from the top of the grain downwards: A is the outermost covering, then the shoot end, then the storage tissue, then the root end.
2. B, near the top, is the coleoptile — the sheath enclosing the plumule.
3. G, at the very bottom, is the coleorrhiza — the sheath enclosing the radicle.
4. So B – Coleoptile and G – Coleorrhiza is the correct pair.

• Statement I about endosperm in castor.
• Statement II about the filiform apparatus.

The truth of each statement.

Castor is an albuminous (endospermic) seed — its endosperm survives to maturity, which is why castor seeds are oily. So Statement I is right. Statement II gets the location wrong: the filiform apparatus sits in the synergids at the micropylar end of the embryo sac, and it exists before there is any embryo at all.

1. Statement I. Castor is albuminous, so the endosperm persists in the mature seed. Correct.
2. Statement II. The filiform apparatus is a set of finger-like projections in the synergids, and it does guide the pollen tube — but it is on the embryo sac, not the embryo.
3. The timing gives it away too: the pollen tube arrives before fertilisation, so there is no embryo yet to have a micropylar side. Incorrect.
4. So I is correct and II is incorrect.

• Statement I about the number of free nuclei during endosperm formation.
• Statement II about endosperm in castor.

The truth of each statement.

Two separate errors. The number of free nuclei formed before cellularisation varies widely between species — NCERT notes it can run into the hundreds in coconut. And castor is albuminous, so its endosperm is not consumed; it persists in the mature seed.

1. Statement I. The free nuclear divisions continue for a variable number of rounds depending on the species — coconut water is a famous example of free-nuclear endosperm with very many nuclei. Incorrect.
2. Statement II. Castor is albuminous, so the endosperm is retained. The statement says the opposite. Incorrect.
3. Both statements are incorrect.
4. Note the direct clash with Q14 on this same paper, where Statement I said the endosperm is not completely consumed in castor — and was correct.

• Assertion about ovule-to-seed and ovary-to-fruit happening together.
• Reason about angiosperm reproduction not requiring water.

The truth of each and whether R explains A.

Both statements are true, but they are about different things. The assertion describes a timing fact — the two conversions run in parallel after fertilisation. The reason describes a reliability fact — angiosperms do not need water for pollination or fertilisation, unlike bryophytes and ferns. True, but it explains why seed formation is dependable, not why the two changes are simultaneous.

1. Assertion. After double fertilisation the ovule becomes the seed while the ovary wall becomes the pericarp. Both are set off by the same event, so they do proceed together. True.
2. Reason. Angiosperm pollination uses wind, water-independent vectors or animals, and the pollen tube carries the gametes — no external water needed. True.
3. Does R explain A? No. Water-independence explains reliability, not simultaneity.
4. So both are true but R is not the explanation.

• Statement I linking albuminous seeds with perisperm.
• Statement II about metabolic activity during dormancy.

The truth of each statement.

Two distinct things are being conflated in Statement I. Albuminous means the endosperm persists. Perisperm is residual nucellus — a different tissue, found only in a few seeds such as black pepper and beet. Most albuminous seeds have no perisperm at all. And Statement II inverts dormancy: during dormancy the embryo is metabolically inactive.

1. Statement I. Albuminous seeds (castor, maize, wheat) retain endosperm. Perisperm is a separate tissue, present only in black pepper, beet and a few others. Equating the two is wrong. Incorrect.
2. Statement II. Dormancy is defined by the embryo being metabolically inactive even when conditions are favourable — that is precisely what distinguishes dormancy from mere quiescence. Incorrect.
3. Both statements are incorrect.

• The plant must be a dicot.
• Its mature seed must retain endosperm (albuminous).
• That endosperm must be oily.

Which plant fits all three conditions.

Three filters, and each one removes an option. Dicot rules out maize and coconut, both monocots. Endosperm in the mature seed rules out bean, which is non-albuminous and stores its food in fleshy cotyledons. That leaves castor — a dicot whose oily endosperm is the source of castor oil.

1. Maize is a monocot — fails the first filter, even though it is albuminous.
2. Coconut is also a monocot — fails the first filter, though its endosperm is famously both liquid and solid.
3. Bean is a dicot but non-albuminous: the endosperm is fully absorbed and food is stored in the cotyledons. Fails the second filter.
4. Castor is a dicot, albuminous, and its endosperm is oily — castor oil comes from it. All three filters passed.

• Vaults, along with diaphragms and cervical caps, are female barrier contraceptives.
• They are inserted into the vagina.

The truth of each statement.

A vault is inserted into the vagina, so it cannot block entry into the vagina — it sits there and blocks entry into the cervix. That single word is what makes Statement I false. Statement II is a plain description and is correct: vaults are reusable female barriers.

1. Statement I. The device is placed inside the vagina, so sperm have already entered the vagina by the time they meet it. What it blocks is passage into the cervix. Incorrect.
2. Statement II. Vaults are indeed reusable barrier devices for females, in the same family as diaphragms and cervical caps. Correct.
3. So I is incorrect and II is correct.

• Assertion about the effectiveness of sterilisation methods.
• Reason about their poor reversibility.

The truth of each and whether R explains A.

Both statements are true — sterilisation is close to 100% effective, and it is very difficult to reverse. But effectiveness and reversibility are separate properties. The method works because the duct is cut and tied, blocking gamete transport; the fact that it is hard to undo is a consequence of the same surgery, not the reason it works.

1. Assertion. Vasectomy (vas deferens) and tubectomy (fallopian tubes) are among the most effective methods available. True.
2. Reason. Both are surgical and very hard to reverse successfully. True.
3. Does R explain A? No. A method is not effective because it is irreversible — the effectiveness comes from the physical block on gamete transport.
4. So both are true but R does not explain A.

• Statement I defining MTP as termination after full term.
• Statement II on why MTP is performed.

The truth of each statement.

MTP is termination of pregnancy before full term — the whole point is that the pregnancy does not continue. NCERT states it is relatively safe during the first trimester, up to about 12 weeks. Statement I says “after full term”, which describes childbirth, not termination.

1. Statement I. Terminating a pregnancy after full term is a contradiction — at full term the pregnancy has already completed. MTP is carried out before that. Incorrect.
2. Statement II. Unwanted pregnancy, whether from casual intercourse, contraceptive failure or rape, is one of the main reasons MTP is performed. Correct.
3. So I is incorrect and II is correct.

• GIFT = Gamete Intra Fallopian Transfer.
• An ovum from a donor is transferred into the fallopian tube of the recipient.

Which woman GIFT is indicated for.

In GIFT a donated ovum is placed into the recipient's fallopian tube, where fertilisation then happens naturally. So the recipient must be able to support fertilisation and pregnancy — what she cannot do is produce an ovum of her own. The technique supplies exactly the thing she lacks.

1. The transfer is of a gamete — specifically an ovum from a donor.
2. It is placed into the recipient's fallopian tube, which must therefore be functional.
3. Fertilisation then occurs inside her body, so she can provide a suitable environment.
4. The deficiency being corrected is her inability to produce an ovum.

• Four factual statements about reproductive health programmes and population.

Which two are correct.

Each statement carries one checkable detail. A names the wrong organisation and conflates two programmes; B and D are standard NCERT facts; C names the wrong institute. So the correct pair is B and D.

1. A. Family planning programmes were launched in India in 1951 by the Government of India, not by WHO; RCH is a later, broader programme. Incorrect.
2. B. World population was about 7.2 billion in 2011 — the figure NCERT quotes. Correct.
3. C. Saheli was developed by the CDRI in Lucknow, not the CCMB. Incorrect.
4. D. Lower maternal and infant mortality means more people survive, which pushes population up. Correct.
5. So B and D.

• Emergency contraceptives are taken after unprotected intercourse.

The window within which they are effective.

The clock starts at coitus, not at any later event, and the window is 72 hours — three days. The purpose is to prevent fertilisation or implantation from occurring at all, so the measurement can only run from the act itself. Implantation happens about a week later, by which point the method is useless.

1. The intervention is meant to act before fertilisation or implantation occurs.
2. So the reference point has to be the coitus.
3. The effective window is 72 hours, i.e. three days.
4. Note that the first two options give the same number of hours — the difference between them is entirely the event they are measured from.

• Four named contraceptives.

Which one is inserted into the uterus.

Sorting by where each is placed answers this immediately. IUDs go into the uterus — Lippe's loop, CuT, Cu7, Multiload, LNG-20. Norplant is a hormonal implant placed under the skin. Vault is a barrier covering the cervix. Saheli is an oral pill.

1. Norplant — a hormonal implant placed subcutaneously, usually in the arm. Not the uterus.
2. Vault — a reusable barrier that covers the cervix. Not the uterus.
3. Saheli — a non-steroidal oral pill taken weekly. Not inserted anywhere.
4. Lippe's loop — a classic intrauterine device, and the clue is in the name of the category: intra-uterine.

• The user wants to delay a first pregnancy or space children.
• So the method must be long-acting and fully reversible.

The ideal method.

Delaying and spacing both call for something that works reliably for a long time without needing action at each act of intercourse, and that can be stopped whenever a pregnancy is wanted. IUDs fit exactly: they last for years, require nothing at the time of intercourse, and fertility returns on removal. NCERT names them specifically as ideal for this purpose.

1. Barrier methods work, but must be used correctly at every single act — effectiveness depends on the user each time.
2. Coitus interruptus and periodic abstinence are natural methods with high failure rates, not ideal for a planned delay.
3. IUDs are inserted once, last for years, need no attention at intercourse, and are immediately reversible on removal.
4. So IUDs are the ideal choice.

• In vivo means fertilisation happens inside the body.
• In vitro means it happens outside, in the laboratory.

Which pair leads to in vivo fertilisation.

Ask, for each technique, what is being transferred. If gametes are moved, fertilisation has not happened yet and will occur inside the body — that is in vivo. If a zygote or embryo is moved, fertilisation already happened in the laboratory — that is in vitro.

1. GIFT transfers a gamete into the fallopian tube, so fertilisation happens there — in vivo.
2. IUI introduces semen into the uterus, so fertilisation happens inside — in vivo.
3. ZIFT transfers a zygote, which means fertilisation already occurred in the lab — in vitro.
4. IVF and ICSI are both laboratory fertilisation by definition.
5. So the in vivo pair is GIFT and IUI.

• The term lactational amenorrhea.

What is absent.

Break the word apart. A- means without, -menorrhea refers to menstrual flow — so amenorrhea is the absence of menstruation. Lactational tells you the cause: intense breastfeeding suppresses ovulation and therefore the menstrual cycle, which is why it works as a natural contraceptive method for up to about six months after childbirth.

1. Split the word: a + menorrhea = absence of menstrual flow.
2. Lactational identifies the cause — breastfeeding.
3. Intense breastfeeding suppresses ovulation, so the cycle does not resume.
4. Effective as a contraceptive for up to about six months after delivery, and only while breastfeeding is exclusive.

• Vasectomy: a small section of the vas deferens is removed and the ends tied.

What the procedure prevents.

The vas deferens is a transport tube, so cutting it blocks transport and nothing else. Sperm are still produced in the testes (and reabsorbed), seminal plasma is still made by the accessory glands, and sexual function is unaffected. Only the sperm's route to the urethra is severed.

1. Vasectomy removes a portion of the vas deferens.
2. Sperm production in the testes carries on unchanged — the sperm are simply reabsorbed.
3. Seminal plasma comes from the seminal vesicles and prostate, which are downstream of the cut and unaffected. Semen is still ejaculated, just without sperm.
4. So what is prevented is the movement of sperm into the urethra.

• Nirodh is a brand of condom.
• Diaphragms are reusable devices covering the cervix.

The truth of each statement.

Both devices are physical barriers — they work by blocking, not by chemistry. Statement I describes Nirodh correctly. Statement II gets the “reusable” part right but calls a diaphragm a chemical barrier, which it is not. Spermicides are chemical and are sometimes used alongside a diaphragm, but the device itself is mechanical.

1. Statement I. Nirodh is a condom, and it works by physically preventing sperm from reaching the ovum. Correct.
2. Statement II. Diaphragms are indeed reusable, but they are physical barriers covering the cervix, not chemical ones. Incorrect.
3. So I is correct and II is incorrect.