Every botany question saved from this paper — all of them from Sexual Reproduction in Flowering Plants — grouped by sub-topic within the chapter. Each carries what was given, what was asked, the concept behind it, the steps in full, the fastest route through, and a figure wherever one makes the answer visible.
8
Questions lost
7
Attempted, wrong
1
Left blank
1
Chapter involved
All eight come from Sexual Reproduction in Flowering Plants, so they are grouped here by sub-topic. On NEET marking they were worth 32 marks, and the seven wrong attempts cost 7 more.
A different shape from the earlier papers: here almost everything was attempted and missed rather than skipped — seven wrong against one blank. Six of the seven turn on two words being swapped, or two neighbouring structures being merged. The knowledge is present; it is the discrimination between close pairs that is failing.
Chapters in this paper — red = wrong · amber = blank · green = correct
Pollination, fertilisation and seed development · 8 questions · 7 wrong · 1 blank
Pollination and outbreeding devices
2 questions · 2 wrong
Q1Pea flowers — which pollination typeMarked wrong
The flowers in the given diagram are The figure shows the papilionaceous flowers of the garden pea, Pisum sativum, with the petals fully open and the stamens and stigma enclosed by the keel.
KEYself - pollinated flowers
cross - pollinated flowers
MARKEDaerial cleistogamous flowers
underground cleistogamous flowers
Given
The flower shown is the garden pea, Pisum sativum.
The petals are open, but the reproductive parts are enclosed by the keel petals.
Asked
The category of pollination these flowers belong to.
Concept to use
Two separate ideas are being tested and they are easy to merge. Chasmogamous means the flower opens and exposes its anthers and stigma; cleistogamous means the flower never opens at all. Pea flowers open normally, so they are chasmogamous — but the anthers and stigma sit hidden inside the keel, so the pollen falls onto its own stigma before anything else can reach it. That is autogamy in an open flower: self-pollinated, but not cleistogamous.
Formula to use
Chasmogamous = opens | Cleistogamous = never opens | Autogamy = self-pollination, possible in either
Baby steps
The flower in the figure is clearly open — the petals are spread. So it cannot be cleistogamous, and both cleistogamous options are out immediately.
In pea the stamens and stigma are enclosed within the keel petals, so foreign pollen has no easy access.
Anthers dehisce while the flower is still in bud, dropping pollen straight onto the stigma of the same flower.
That makes pea a self-pollinated flower — which is exactly why Mendel chose it: he could control crossing, and left alone the plants bred true.
Answer: self-pollinated flowers.
Answer
self - pollinated flowers
Shortcut
Look at the picture before reading the options. If the petals are open, every “cleistogamous” option dies on the spot — and here that removes two of the four at a glance, leaving only self- versus cross-pollinated.
Where it went wrong
“Aerial cleistogamous” is a contradiction with the figure: a cleistogamous flower by definition does not open, yet the flower drawn is wide open. The two ideas — self-pollinating and cleistogamous — got merged. Keep them apart: cleistogamy guarantees selfing, but selfing does not require cleistogamy. The true cleistogamous NCERT example is Viola (and Oxalis, Commelina), not pea.
Q42Self-incompatibility and autogamyMarked wrong
Given below are two statements. Statement I: Self-incompatibility promotes inbreeding, by discouraging cross-pollination. Statement II: If the anther and stigma are placed at different positions in the same flower, it can prevent autogamy.
MARKEDBoth statement I and statement II are correct.
Both statement I and statement II are not correct.
Statement I is correct, but statement II is incorrect.
KEYStatement I is incorrect, but statement II is correct.
Given
Statement I — a claim about what self-incompatibility promotes.
Statement II — a claim about anther and stigma position.
Asked
Which statements are correct.
Concept to use
Continued self-pollination causes inbreeding depression, so flowering plants have evolved a whole set of devices to avoid it. Every one of those devices — different maturation times, different positions, self-incompatibility, unisexual flowers — discourages selfing and encourages cross-pollination. Statement I attributes the exact opposite purpose to self-incompatibility.
Formula to use
Outbreeding devices all → discourage autogamy → promote cross-pollination (outbreeding)
Baby steps
Statement I. Self-incompatibility is a genetic mechanism that prevents a plant’s own pollen from fertilising its ovules. Blocking self-pollen forces pollen to come from another plant — that is outbreeding, not inbreeding. The statement is exactly backwards. Incorrect.
Statement II. Placing anther and stigma at different positions (herkogamy) means pollen cannot easily fall on the flower’s own stigma, which prevents autogamy. This is one of the standard outbreeding devices. Correct.
So: Statement I incorrect, Statement II correct.
Answer
Statement I is incorrect, but statement II is correct.
Shortcut
Every outbreeding device in this chapter has the same purpose — stop selfing, encourage crossing. So any statement claiming one of them promotes inbreeding is false on sight, without needing to know the mechanism. One rule covers self-incompatibility, dichogamy, herkogamy and unisexuality together.
Where it went wrong
Both statements were accepted. Statement II is correct and reads naturally, and its correctness seems to lend credibility to Statement I — but each statement must be judged alone. Note that Statement I contains its own contradiction: “promotes inbreeding by discouraging cross-pollination” describes the opposite of what a self-incompatibility system does. Reading the reason clause inside the statement would have caught it.
Pollen–pistil interaction and fertilisation
2 questions · 2 wrong
Q10Fate of incompatible pollen on the stigmaMarked wrong
If a wrong pollen (from other species or self-incompatible) lands on stigma A. pollen germinates, but pollen tube cannot grow in style B. pollen germinates, grows in style but cannot enter the ovary C. does not germinate at all
A only
MARKEDA, B, and C
B only
KEYA and C only
Given
Pollen from another species, or self-incompatible pollen, lands on the stigma.
Asked
Which of the three described outcomes actually occur.
Concept to use
The pistil has the ability to recognise pollen chemically and either accept or reject it. Rejection happens early — NCERT states that incompatible pollen either fails to germinate on the stigma, or germinates but has its tube stopped in the style. There is no third checkpoint at the mouth of the ovary: once a tube has successfully traversed the style, it reaches the ovule.
Formula to use
Compatible pollen → germinates → tube through style → ovule. Rejection occurs at the stigma or in the style, not later.
Baby steps
C — does not germinate at all. The commonest response: the stigma recognises the pollen as foreign and never lets it start. Occurs.
A — germinates but the tube cannot grow in the style. The second checkpoint: the tube starts but is arrested in the style. Occurs.
B — grows through the style but cannot enter the ovary. There is no such barrier described; a tube that has crossed the style goes on to the ovule. Does not occur.
So the correct pair is A and C.
Answer
A and C only
Shortcut
Think of the pistil as having exactly two gates — the stigma surface and the style. Any option describing a rejection at a third point, deeper in, is invented. Since the question offers three statements and one describes a third gate, the answer is the other two.
Where it went wrong
Choosing “A, B and C” treats every plausible-sounding statement as true. Options phrased as “all of the above” are correct less often than they look, and here B is the planted extra. When three statements describe a sequence of increasingly deep failures, ask whether the deepest one is a real checkpoint or just an extrapolation.
Q31What syngamy meansMarked wrong
Syngamy in angiosperms means fusion of
two polar nuclei in central cell
MARKEDmale gamete and one polar nucleus
male gamete and two polar nuclei
KEYmale gamete and female gamete
Given
Double fertilisation in an angiosperm, involving two male gametes.
Asked
The definition of syngamy.
Concept to use
Double fertilisation involves two separate fusions with two different names, and the options here are built entirely out of confusing them. Syngamy is the true fertilisation event: one male gamete fuses with the egg (the female gamete) to give the diploid zygote. Triple fusion is the other one: the second male gamete fuses with the two polar nuclei to give the triploid primary endosperm nucleus. Three nuclei, hence “triple”.
Break the word: syn = together, gamos = marriage. It is the fusion of two gametes.
In the embryo sac the female gamete is the egg cell — not a polar nucleus. Polar nuclei are not gametes.
So syngamy = male gamete + egg → zygote (2n).
Check the distractors: “male gamete + two polar nuclei” is triple fusion; “two polar nuclei” alone is just the formation of the secondary nucleus; “male gamete + one polar nucleus” is not a real event at all.
Answer: male gamete and female gamete.
Answer
male gamete and female gamete
Shortcut
Count the nuclei in the option. Syngamy fuses two nuclei; triple fusion fuses three. Any option naming three participants is triple fusion by definition, and any option naming a polar nucleus is not syngamy.
Where it went wrong
“Male gamete and one polar nucleus” is not a process that happens anywhere in the plant — it is a manufactured mixture of the two real events. When an option describes a hybrid of two processes you know, treat that as a warning sign rather than a plausible middle ground.
Post-fertilisation structures
2 questions · 2 wrong
Q11Reading an embryo diagramMarked wrong
Identify the correct statement w.r.t the image given below. The figure shows a dicot embryo with two rounded lobes at the lower end, attached by a chain of cells to a swollen cell at the top.
KEYThe figure depicts a heart shaped embryo with the suspensor labelled as A.
The figure depicts a mature embryo with the radicle labelled as A.
MARKEDThe figure depicts a heart shaped embryo with the radicle labelled as A.
The figure depicts a globular embryo with the suspensor labelled as A.
Given
A dicot embryo with two lobes at one end.
Label A points at the chain of cells joining the embryo to the swollen basal cell.
Asked
Which statement correctly names both the stage and the labelled part.
Concept to use
Two things must be read off the figure independently, and the options mix them deliberately. The stage is told by the shape: a ball with no lobes is globular; two lobes beginning to appear make it heart-shaped; a fully formed radicle and plumule make it mature. The label is told by position: the chain of cells connecting the embryo to the micropylar end is always the suspensor, whose job is to push the embryo into the endosperm.
Formula to use
Proembryo → globular → heart-shaped → mature | suspensor = the stalk, radicle = the root tip
Baby steps
Look at the shape first: the lower end has two distinct lobes — the developing cotyledons. That is the heart-shaped stage, so “globular” and “mature” are both out.
Now the label. A points at a chain of cells forming a stalk, not at a tip of the embryo body.
That stalk is the suspensor. It develops from the basal cell and anchors the embryo, pushing it into the nutritive endosperm.
The radicle is part of the embryo body and only becomes identifiable at the mature stage — it is never a stalk of cells.
So: heart-shaped embryo, with the suspensor labelled A.
Answer
The figure depicts a heart shaped embryo with the suspensor labelled as A.
Shortcut
Answer the two halves separately and cross out as you go. Stage from the lobes (heart-shaped) removes two options; part from the stalk (suspensor) removes one more. Two independent decisions, four options, one survivor — and neither decision needs the other.
Where it went wrong
The stage was read correctly and the label was not. A radicle is a tip of the embryo body; the suspensor is a chain of cells outside it. In the figure A points to a beaded stalk, which cannot be a radicle. Whenever an option pairs two facts, verify both — getting one right is worth nothing here, and the paper builds options precisely to reward only the pair.
Q20Ploidy of nucellus and perispermMarked wrong
The ploidy of nucellus and perisperm, respectively are
haploid and haploid
KEYdiploid and diploid
MARKEDdiploid and triploid
triploid and diploid
Given
Nucellus — the tissue of the ovule surrounding the embryo sac.
Perisperm — nutritive tissue found in some seeds, e.g. black pepper and beet.
Asked
Ploidy of each.
Concept to use
Trace every seed tissue back to its origin. The nucellus is maternal sporophyte tissue — part of the parent plant’s body — so it is diploid. Perisperm is simply the nucellus that failed to be used up during seed development; it is residual nucellus and therefore carries the same ploidy. Nothing fuses to make either of them, so neither can be triploid.
Formula to use
Perisperm = persistent nucellus → both are maternal sporophyte tissue → both 2n
Baby steps
The nucellus is part of the ovule wall, produced by the parent sporophyte. Parent body tissue is diploid (2n).
During seed formation the endosperm usually consumes the nucellus completely.
In some seeds — black pepper, beet, Nymphaea — a portion of the nucellus persists. That residue is called the perisperm.
Since it is the same tissue, unchanged, it is also diploid (2n).
Answer: diploid and diploid.
Answer
diploid and diploid
Shortcut
Only one tissue in the seed is triploid — the endosperm, from the fusion of two polar nuclei with one male gamete. Everything else is either maternal (2n) or the embryo (2n). So the moment a question offers “triploid” for anything other than endosperm, that option is wrong.
Where it went wrong
Marking the perisperm as triploid comes from confusing it with the endosperm — both are nutritive tissues in a seed, so they feel interchangeable. They are not: endosperm is a fertilisation product (3n), perisperm is leftover mother tissue (2n). One sentence separates them permanently.
Apomixis and reproductive arithmetic
2 questions · 1 wrong · 1 blank
Q37Statements about apomixisMarked wrong
Select the correct option with respect to apomixis. (i) Apomixis is a form of sexual reproduction that mimics asexual reproduction. (ii) Seeds developed through apomixis, have advantages in horticulture and agriculture. (iii) It is seen in plants such as some species of Asteraceae and grasses. (iv) Apomictic seeds can show segregation of characters in the hybrid progeny.
Only (i) and (iv) are correct
KEYOnly (ii) and (iii) are correct
Only (i), (ii), and (iii) are correct
MARKEDAll (i), (ii), (iii), and (iv) are correct
Given
Four statements about apomixis.
Asked
Which are correct.
Concept to use
Apomixis is asexual reproduction that mimics sexual reproduction — seeds are produced without fertilisation, so the embryo is genetically identical to the mother. Because there is no meiosis and no fusion, there is no segregation and no recombination: the progeny cannot vary. That single fact settles two of the four statements at once, since both (i) and (iv) contradict it.
Formula to use
Apomixis: no meiosis, no fertilisation → embryo is a clone of the parent → no segregation in the progeny
Baby steps
(i) says apomixis is sexual reproduction mimicking asexual. It is the other way round — it is asexual reproduction mimicking sexual, because a seed (normally a sexual product) is formed without fertilisation. Incorrect.
(ii) Hybrid vigour is retained generation after generation, so farmers need not buy fresh hybrid seed each year. A genuine agricultural advantage. Correct.
(iii) NCERT names Asteraceae and grasses as the families where apomixis is common. Correct.
(iv) Segregation requires meiosis. Apomictic embryos are clones, so characters cannot segregate — that is precisely the benefit described in (ii). Incorrect.
Answer: only (ii) and (iii).
Answer
Only (ii) and (iii) are correct
Shortcut
Statements (ii) and (iv) are logically incompatible: the advantage in (ii) is that hybrid characters do not segregate, so (iv) must be false if (ii) is true. Spotting that the two contradict each other rules out “all of the above” instantly and points at the answer.
Where it went wrong
Marking all four correct means the reversal in (i) went unnoticed — the two words “sexual” and “asexual” are simply swapped. This is the same reversal pattern that appeared in Q42 of this paper and in the botany paper’s Q130. When a definition is stated in an option, read it word by word rather than recognising its shape.
Q39Meiotic divisions needed for 80 zygotesNot attempted
How many meiotic divisions are required for the formation of 80 zygotes in an angiospermic plants?
40
KEY100
80
160
Given
80 zygotes are to be formed in an angiosperm.
Asked
Total number of meiotic divisions required.
Concept to use
Each zygote needs one egg and one male gamete, but the two sides of the plant produce gametes at very different rates. On the female side, one meiosis yields just one functional egg (four megaspores form, three degenerate). On the male side, one meiosis yields four pollen grains, and each pollen grain carries two male gametes — but only one of those two performs syngamy, so one pollen grain serves one zygote. Count the two sides separately and add.
Female side. 80 zygotes need 80 eggs. Each megaspore mother cell undergoes one meiosis and gives one functional megaspore → one embryo sac → one egg. So 80 meioses.
Male side. 80 zygotes need 80 male gametes for syngamy, so 80 pollen grains are needed (each supplies one).
One microspore mother cell undergoes one meiosis and produces 4 pollen grains.
Number of meioses on the male side = 80 ÷ 4 = 20.
Total = 80 + 20 = 100 meiotic divisions.
Answer
100
Shortcut
Remember the asymmetry as a ratio: for n zygotes it is always n meioses on the female side and n/4 on the male side, giving 5n/4 in total. Here 5(80)/4 = 100, in one line. The same reasoning gives mitotic counts if a variant asks for those instead.
The distractor 160 comes from doubling 80 (treating both sides as needing 80 meioses); 80 comes from counting only the female side. Both are stops along the correct route, which is why they are on the list — name what you are counting at each step.
What the eight have in common
One chapter, seven wrong and one blank — and six of the seven wrong answers
come down to two habits rather than two gaps.
1 · Definitions read backwards — Q37, Q42
Q37 statement (i) called apomixis “sexual reproduction that mimics asexual”;
it is the reverse. Q42 statement I said self-incompatibility “promotes inbreeding
by discouraging cross-pollination”; every outbreeding device in the chapter does
the opposite. In both cases the two key words were simply swapped.
Fix: when an option states a definition, read it word by word rather than
recognising its shape — and for this chapter hold one rule: every device
exists to discourage selfing.
2 · Two similar structures merged — Q11, Q20, Q31
Suspensor confused with radicle (Q11), perisperm with endosperm (Q20), syngamy with
triple fusion (Q31). Each pair sits in the same paragraph of the textbook and each
was resolved the wrong way. Fix: for every pair like this write one sentence
that separates them — endosperm is a fertilisation product (3n), perisperm is
leftover mother tissue (2n) — rather than learning them as neighbours.
3 · The figure was available and not used — Q1, Q11
Q1 shows a wide-open pea flower, yet a cleistogamous option was chosen —
cleistogamous flowers by definition never open. Q11 shows a beaded stalk labelled A,
yet it was called a radicle. Both answers are visible in the picture.
Fix: in a diagram question, describe what you can see in words before reading
a single option.
Four rules that cover the chapter
Chasmogamous vs cleistogamous is about opening; autogamy is about selfing.
Pea is open and self-pollinated. (Q1)
Ploidy by origin: maternal tissue 2n, gametophyte n, endosperm 3n,
embryo 2n. Only the endosperm is triploid. (Q20)
Two fusions: syngamy joins two nuclei, triple fusion joins three. (Q31)
Gamete arithmetic: for n zygotes, n meioses on the female side and
n/4 on the male side — 5n/4 in total. (Q39)
The correct option is marked KEY and the option selected in the test is marked MARKED; questions with no marked option were left unattempted. All figures have been drawn fresh for these notes.