Sexual Reproduction in Flowering Plants Mock Test – Class 12 Biology

1. Arrange the following events in a normal sexual reproductive sequence leading to fruit and seed formation.
P. Ovary develops into fruit
Q. Pollination places suitable pollen on the stigma
R. Double fertilisation occurs
S. Ovules develop into seeds

2. Seed-viability records are summarised below.

Which conclusion is justified by these records alone?

3. In a species with , a mature seed contains a diploid nucellar embryo and triploid endosperm. How many chromosomes are expected in each respectively?

4. In two developing seeds, fertilisation is normal. In Seed P, endosperm development fails almost immediately after triple fusion. In Seed Q, abundant endosperm forms first and is largely consumed only after substantial embryo growth. Which comparison is most accurate?

5. Four anther sections are summarised below.

Which section matches the usual bilobed, tetrasporangiate anther described for flowering plants?

6. A student claims that every false or accessory fruit is simply a parthenocarpic fruit under another name. Which observation most directly disproves the claim?

7. The following records compare fusion events inside an embryo sac.

Which record correctly represents triple fusion?

8. A primary endosperm nucleus undergoes many rounds of nuclear division, but a mutation blocks cytokinesis throughout the observed period. Which tissue condition should predominate?

9. In a typical bisexual flower, the two whorls that directly produce the male and female reproductive structures are:

10. A plant population is forced through repeated generations of self-pollination. Over time, reproductive performance and vigour decline, whereas comparable plants receiving cross pollen maintain better performance. Which interpretation best fits the observation?

11. In maize, pollen from the tassel of Plant P is carried to silks belonging to a female flower on the same Plant P. Which combined description is correct?

12. Four bisexual flowers have the following reproductive conditions.

Which flower shows both a temporal and a spatial barrier to same-flower autogamy?

13. Two neighbouring cells in the nucellus of a young ovule are both diploid. Cell P remains an ordinary nucellar cell. Cell Q is larger, has dense cytoplasm and a prominent nucleus, and later undergoes meiosis to form four haploid megaspores. Which evidence most specifically identifies Q as the megaspore mother cell?

14. Match each part of a typical dicot embryo with its correct positional or structural description. Each Column II entry is used once.

15. A compatible pollen tube has grown through the style and reached an ovule. It enters through the micropylar end and is subsequently directed into one of the two cells flanking the egg. Which structure-function pairing best explains the final part of this route?

16. Which classification of the following examples is consistent with their mature storage-tissue condition?

17. In Plant P, several carpels are fused into a single compound pistil, as in Papaver. In Plant Q, several carpels remain free, as in Michelia. Which relationship is correct?

18. Use the arrangement described below. A young microsporangium has four concentric wall regions P, Q, R and S arranged from the exterior toward the central sporogenous tissue. S directly borders the sporogenous tissue. Which mapping correctly represents the normal wall-layer order?

19. A developing monocot embryo forms a normal shoot apex, coleoptile, radicle and coleorrhiza, but the scutellum fails to develop. Which embryonic component is specifically missing?

20. Assertion: Apomixis produces seeds without fertilisation.
Reason: Apomixis is a form of asexual reproduction that mimics seed formation normally associated with sexual reproduction.

21. A monocot seed contains a normal embryo with one scutellum, but the mature seed shows almost no persistent endosperm. Which conclusion is most appropriate?

22. Two compatible pollen types are shed by the same species. Type P is shed in the two-celled condition, while Type Q is shed in the three-celled condition. A treatment applied only after shedding blocks any further generative-cell mitosis but does not damage already formed male gametes. Which outcome is most likely?

23. Which pair of symbolic relations correctly represents the nuclear and cellular organisation of the common mature embryo sac?

24. A viable mature seed remains ungerminated while lying in dry soil. When water becomes available under otherwise suitable oxygen and temperature conditions, it germinates promptly without any additional dormancy-breaking treatment. Which interpretation is most justified?

25. If a compatible pollen tube reaches a synergid but fails to discharge its two male gametes, the most direct consequence is that:

26. Arrange the operations for a unisexual female flower used in a controlled cross.
P. Apply pollen from the selected male parent when the stigma becomes receptive
Q. Bag the female flower before unwanted pollen can reach it
R. Rebag after applying the selected pollen

27. Pollen grains on Plant X are marked with a harmless tracer. Later, the tracer is detected on receptive stigmas of Plant Y, which belongs to the same species and is a separate individual. No marked pollen was originally present on Y. The recorded transfer is:

28. In a developing endosperm, repeated divisions of the primary endosperm nucleus continue normally, but wall formation around the daughter nuclei is experimentally delayed. Which condition should persist longer than usual?

29. Male-bee behaviour and pollen transfer are recorded for two groups of Ophrys flowers.

Which inference is most strongly supported?

30. Arrange the following broad events of the normal flowering-plant reproductive cycle.
P. Meiosis produces haploid spores
Q. Mature gametophytes are established
R. Compatible pollen reaches the stigma and a pollen tube grows
S. Double fertilisation occurs
T. Embryo, endosperm, seed and fruit development proceed

31. Pollen grains are exposed experimentally to harsh conditions that destroy most ordinary cellular material. After treatment, sculptured outer walls remain recognisable even though the internal contents are no longer functional. Which property most directly explains persistence of the outer walls?

32. During ovule-to-seed transformation, Structure P develops from the integuments, while Opening Q persists from the gap originally left between those integuments. Which identification is correct?

33. Match each monocot embryonic structure with its correct description. Each Column II entry is used once.

34. In Ovule P, syngamy is prevented but triple fusion succeeds. In Ovule Q, syngamy succeeds but triple fusion is prevented. Which immediate comparison is correct?

35. All pollinating animals are removed from a plant whose flowers cannot transfer pollen directly to their own stigmas, but pollen can normally move between different flowers on that plant. Which pollination route is most directly reduced by removing the transfer agents?

36. Assertion: Dioecy prevents both autogamy and geitonogamy.
Reason: Xenogamy is pollen transfer between flowers borne on different plants of the same species.

37. Four labelled regions of a dicot embryo are summarised below.

Which sequence correctly identifies P, Q, R and S?

38. Use the arrangement described below. Several cells of the nucellus surrounding an embryo sac begin repeated divisions, protrude into the embryo-sac region and develop into additional embryos. These embryos are best described as:

39. Ovary P contains a single ovule, whereas Ovary Q contains many ovules. All ovules in both ovaries are successfully fertilised and each develops normally. Which conclusion is justified?

40. Which feature most directly explains why seed formation reduces dependence of the young sporophyte on free external water at the time of dispersal?

41. Mature seeds P and Q show the following tissue pattern.

Which classification is correct?

42. A monoecious plant bears separate male and female flowers on the same individual. Pollen can readily move between these flowers, but the plant also possesses a recognition system that rejects pollen carrying the same incompatibility identity as the female tissue. What outcome is most likely for same-plant pollen transfer?

43. Two seed lots have similar initial viability. Lot P is stored dry under favourable long-term storage conditions, whereas Lot Q remains continuously warm and moist but is prevented from germinating mechanically. After several years, viability is much higher in P. Which explanation is most consistent with seed biology?

44. A mature seed is opened without damaging its contents. A protective outer covering surrounds an embryo with cotyledonary tissue and an embryonal axis, while a small pore remains in the covering at a position corresponding to an opening once present in the ovule. The pore is the:

45. A plant produces two floral forms. Form P remains closed and sets seed even when pollinators are excluded. Form Q opens normally and can receive pollen from other flowers. The plant shows the same floral pattern represented by Viola, Oxalis and Commelina. Which interpretation is correct?

46. Before fertilisation in a normal diploid flowering plant, which ploidy relationship is expected among ovular tissues?

47. All pollen produced by a plant has lost viability before reaching the stigma. No pollen tubes form, yet treatment of the ovaries with a suitable growth substance produces mature seedless fruits. Which conclusion is best supported?

48. A mature embryo sac contains a normal egg and synergids, but the two polar nuclei fail to develop. A pollen tube successfully delivers two normal male gametes. What is the most direct expected result?

49. Two hybrid crop lines both form seeds apomictically. Line P already has a desirable high-yield hybrid genotype, whereas line Q has an undesirable low-yield hybrid genotype. After repeated seed generations, each line continues to resemble its own starting hybrid closely. Which conclusion is best supported?

50. Dicot and monocot embryos are compared below.

Which interpretation is best supported?