Plant Growth and Development Mock Test – Class 11 Biology

1. Identical plants are divided into two groups. Group P receives a light condition that promotes flowering, while Group Q remains under a non-promotory light condition. A change in internal regulator activity is detected in P before flowering begins. Which inference is most appropriate?

2. A shoot becomes visibly larger within a short period after watering. No measurement is made after water is withdrawn, and no evidence of new dry matter or sustained enlargement is available. The most justified conclusion is:

3. Ethephon application to cucumber plants is commonly used to:

4. Descendants of the same root apical meristem are traced. Cells directed toward the root-cap region become protective root-cap cells, while cells displaced laterally toward the periphery mature as epidermis. This pattern demonstrates that:

5. Arrange these events in a simplified ethylene-promoted ripening sequence.
P. Ripening-related colour, texture and flavour changes become evident.
Q. A responsive unripe fruit is exposed to ethylene.
R. Respiratory activity rises during the climacteric.
S. The fruit advances toward a ripe state.

6. Identical seedlings are grown in two aerated solutions at a favourable temperature. Solution P contains all essential mineral elements, while Solution Q contains water but no renewed mineral supply. Q grows briefly and then shows poor dry-mass accumulation. The strongest conclusion is:

7. A mature mango tree remains vegetative under conditions in which flowering is desired. Which regulator-related treatment is associated with inducing flowering in this case?

8. Assertion: Ethylene treatment may promote germination of a viable dormant seed.
Reason: Ethylene can help break dormancy, whereas ABA commonly supports its maintenance.

9. Cytokinin responses are compared in two tissues.

Which conclusion best integrates the records?

10. Two leaves are followed for . Leaf P increases from to , while leaf Q increases from to . The strongest conclusion based only on absolute growth rate is:

11. Equal rosette plants and equal branched shoots receive two unknown regulator treatments. Treatment P causes rapid internode elongation before flowering in the rosette plants. Treatment Q increases outgrowth of lateral buds without removing the shoot apex. Which identification is best supported?

12. Beet plants receive four treatments before flowering.

Which comparison most directly distinguishes bolting from an increase in stem girth?

13. Rice seedlings infected by Gibberella fujikuroi become unusually tall and slender rather than merely showing local tissue damage. This foolish-seedling or bakanae condition first suggested the presence of:

14. Assess the following statements concerning open growth in plants.
I. Active meristems continuously add new cells to the plant body.
II. Open growth requires every mature tissue to remain mitotically active.
III. New organs or tissues may be produced while suitable meristems persist.
IV. Open growth means that no individual organ can ever stop growing.

15. Young plant tissues are cultured under four conditions.

Which conclusion best fits the complete record?

16. Equal transverse marks are placed along a young root and remeasured after .

The principal zone of root elongation lies in:

17. Use the lineage described below. In the early region, each dividing embryonic cell produces two daughters and both continue dividing. In a later region, one branch continues mitosis while several derivatives leave the lineage and specialise. This arrangement represents:

18. Assess the following statements concerning auxin-induced parthenocarpy.
I. Fruit development begins without fertilisation.
II. Tomato can show this response after auxin treatment.
III. The process is equivalent to seed germination inside an ovary.
IV. The resulting fruit is expected to lack normally formed fertilisation-derived seeds.

19. Which of the following statements about abscisic acid are valid?
I. It broadly inhibits plant growth and metabolism.
II. Its early study was associated with abscission and dormancy.
III. Its biological role is restricted entirely to causing organ separation.
IV. It can influence several developmental and stress-related processes.

20. Seedling elongation is measured after four treatments.

Which interpretation is most strongly supported?

21. Arrange the events linking daughter-cell fate with geometric growth.
P. Both daughters retain division capacity.
Q. A dividing cell undergoes mitosis.
R. The number of dividing cells increases multiplicatively.
S. The total growth curve becomes progressively steeper under unrestricted conditions.

22. Review the following statements about evidence used in plant growth regulator discoveries.
I. Coleoptile-tip experiments located a region involved in perception or transmission before auxin was chemically isolated.
II. A sterile fungal filtrate reproducing bakanae elongation supported the existence of a diffusible substance.
III. Strong callus proliferation after addition of certain supplements indicated an extra cytokinesis-promoting factor beyond auxin alone.
IV. Similar inhibitory effects alone proved that inhibitor-B, abscission II and dormin were chemically identical.

23. Identical flowering shoots are placed in separate chambers. Shoot P receives normal air, while Shoot Q receives ethylene. Flowers on Q age and detach earlier. The strongest conclusion is:

24. During seed development, ABA activity increases as the seed approaches maturity. The seed develops dormancy and survives substantial drying before dispersal. These changes are best interpreted as:

25. Assertion: Ethephon may be used both to synchronise flowering in pineapple and to increase yield in cucumber.
Reason: Ethylene released from ethephon can promote flowering in pineapple and increase female flower formation in cucumber.

26. Evaluate the following statements about auxin in developing tissues.
I. It can support cell-division-related processes.
II. It contributes to xylem differentiation.
III. Its role in division means every auxin-treated cell must remain permanently meristematic.
IV. Its vascular effect is distinct from its use as a selective herbicide.

27. Match each crop with the ethylene-related reproductive application described. A Column II entry is used once.

28. Dormant potato tubers are stored under identical conditions. Tubers in Group P remain untreated, while those in Group Q receive ethylene and develop visible sprouts sooner. The response represents:

29. Living shoot tips are divided into two hydrated groups supplied with equal nutrients and suitable temperature. Group P receives adequate oxygen, while Group Q is kept oxygen-limited. Group P shows much greater permanent enlargement. The result most strongly supports the view that:

30. Fruit retention is recorded under four conditions.

Which condition is most likely to show the greatest abscission?

31. Shoot treatments produce the following responses.

Which conclusion best integrates the pattern?

32. Growth responses are recorded under four combinations.

Which conclusion best integrates the results?

33. Identical seedlings receive equal total light, water, minerals and temperature. Group P receives light evenly from several directions, while Group Q receives it mainly from one side and develops directional curvature. The most appropriate interpretation is:

34. A leaf increases in area from to during . Its average area growth rate during this interval is:

35. A mutant plant cannot close its stomata in response to ABA. During a dry period, it is most likely to:

36. Assertion: Auxin produced near a growing apex may influence development in a different region of the same organ.
Reason: Auxin can migrate from its production site to tissues where its physiological action is expressed.

37. Place the following events after ethephon is applied to a responsive plant.
P. Ethylene-dependent responses become visible.
Q. Aqueous ethephon is absorbed by plant tissues.
R. Ethephon is transported within the plant.
S. Ethylene is released gradually.

38. Assertion: A seedling may grow poorly at temperatures both below and above its optimum.
Reason: The optimum temperature for growth may differ among plant species.

39. Assertion: A plant growth regulator may act individually in one developmental event and interact with another regulator in a different event.
Reason: Plant growth regulators are generally small molecules.

40. Study the spatial arrangement below. A larkspur plant bears one leaf form on its juvenile region and a different leaf form on shoots produced during the adult phase. Both regions developed in the same habitat. The pattern demonstrates:

41. Two living tissues show a increase in fresh mass after treatment. Tissue P also shows increased dry mass and cell number, and the gain persists after the treatment ends. Tissue Q shows no change in dry mass or cell number and returns to its original mass after water is removed. Which interpretation is most appropriate?

42. Examine the following statements about the metabolic character of plant growth.
I. Increase in protoplasmic material is commonly associated with cellular growth.
II. Anabolic processes contribute to the building of cellular components.
III. Catabolic processes can supply energy for growth activities.
IV. An increase in fresh mass alone always proves that growth has occurred.

43. A tissue increases in dry mass from to during . Using initial mass as the common basis, its relative growth rate is:

44. Use the horticultural arrangements described below.
Site P: An intact shoot apex suppresses axillary buds.
Site Q: The shoot apex is removed and lateral branches develop.
Site R: An unrooted stem cutting receives auxin at its cut base and forms roots.
Site S: An unfertilised tomato ovary receives auxin and develops into a seedless fruit.
Which pair represents direct horticultural auxin applications rather than manipulation of the plant's existing apical dominance?

45. Auxin is applied continuously to a leaf as it ages. Early in development the treatment delays premature separation, but at an old mature stage abscission is promoted. Which interpretation best explains the reversal?

46. Four leaves are observed for .

Which pair has equal relative growth rates but a twofold difference in absolute growth rates?

47. Weed-control results from four sites are shown below.

Which principle explains the pattern?

48. Identical seedlings receive equal water, minerals, oxygen and light but are maintained at , or . Growth is greatest at and low at both other temperatures. Which inference is justified?

49. Assertion: Embryonic growth may shift from an early geometric pattern to a partly arithmetic pattern as development proceeds.
Reason: This shift occurs when every daughter cell continues to retain division capacity.

50. As fruits mature, auxin-related retention declines and ethylene concentration rises. A mutation makes cells of the abscission zone insensitive to ethylene while leaving other fruit tissues responsive. Which outcome is most likely?