XII Botany Karachi Board MCQs

1. When the plasmolysed cells are again placed in water, there is a recovery to the original condition due to endosmosis of water. This is called __________.

(Plasmolysis, Incipient Plasmolysis, Complete Plasmolysis, Deplasmolysis)

2. Rizobium is found in __________.

(Roots of wheat, Roots of rice, Root-nodules of pea, Deplasmolysis)

3. The oxygen released in photosynthesis comes from __________.

(Carbon dioxide, Carbohydrates, Water, None of above)

4. Cell organella related with respiration is __________.

(Mitochondria, Centriole, Coldgi Body, Nucleus)

5. The end products of glycolysis is __________.

(Citric Acid, Pyruvic Acid, Ethyl alcohol, Glyceraldehyde)

6. Positive geotropism is observed in __________.

(Primary roots, Sucking roots, Aerial roots, None of these)

7. Absorption of water by roots is increased when __________.

(Transpiration rate is less, Salt absorption is increased, Transpiratin rate is incrreased. Photosynthesis rate is increased)

8. In plant cell vacuole contains __________.

(Gases, Vacuum, Dissolved Mineral salts, Water)

9. The union of male and female gametes results in the formation of __________.

(Aplanospore, Meiospore, Zygote, None of these)

10. Enzymes are basically __________.

(Proteins, Vitamins, Fats, Carbohydrates)

11. Semi-permeability is the property of __________.

(Plasma Membrane, Cell wall, Colgi body, Endoplasmic Reticulum)

12. The initial stage of water absorption by root cell is by __________.

(Osmosis, Imbibition, Absorption, Diffusion)

13. Duplication of DNA is called __________.

(Transduction, Transcription, Translation, Replication)

14. Watson and Crick are credited for finding __________.

(DNA is the carrier of genetic information, DNA is a double-stranded helix, RNA is a double-stranded helix, DNA is composed of sugar, phosphoric acid and nitrogenous bases)

15. __________ is the unit of inheritance.

(Phenotype, Genotype, Gene, None of these)

16. __________ organalle is related with genetic engineering.

(Plastids, Plasmids, Mutations, Hybrid Vigour)

17. The pollen tube which moves through the style towards ovary is an example of __________.

(Phototropism, Thigmotropism, Hydrotropism, None of these)

18. Cytokinins promote __________.

(Cell division, Apical growth, Tallness, Dwarfness)

19. The number of chromosomes in humans is __________.

(56, 46, 36)

20. The tendency of genes to remain together is called __________.

(Linkage, Crossing over, Gena mutation)

21. Cross fertilization of phenotypically dominant individual with a homozygous recessive individual is __________.

(Dihybrid cross, Munohybrid Cross, Test Cross)

22. Cytokinesis is the division of __________.

(Nucleus, Cytoplasm, Vacuole)

23. Inheritance of acquired characters was suggested by __________.

(Wallace, Aristotle, Lamarck)

24. Translocation of organic food substances takes place through __________.

(Xylem, Phloem, Endodermis)

25. Absorption of water and mineral salts from the soil takes place through __________.

(Older roots, Younger roots, Both of them)

26. Respiration in plants takes place during __________.

(Day time only, Night time only, Day and night both)

27. Process of transpiration is effected by __________.

(Light only, temperature only, both of these)

28. Mitosis takes place in __________.

(Somatic Cell, Sickle cell, Zylem Cell)

29. Transpiration is necessary for __________.

(Movement of Curvature, Synthesis of food material, Conduction of Water)

30. Munch Hypothesis was proposed to explain __________.

(Translocation, Ascent of Sap, Transpiration)

31. Human male set of chromosomes is __________.

(44 + xy, 44 + xx, 44 + 00)

32. The first stable compound formed during photosynthesis is __________.

(ATP, 3PGA, Pyruvic Acid)

33. During Meiosis crossing over takes place at __________.

(Leptotene, Diplotene, Diakenesis)

34. Paleontology evidences are considered as evidence of __________.

(Vestiges, Fossils, Embryo)

35. The genotype of Hybrid is __________.

(T, Tt, tt)

36. The blood group of a man with neither antigens is __________.

(‘O’ Group, ‘A’ Group, ‘AB’ Group)

37. The changes in chromosomes are called __________.

(Linkage, Crossing over, Chromosomal aberration)

38. The growth in plants can be measured by __________.

(Photometer, Respirometer, Auxanometer)

39. Oxygen is evolved during photosynthesis from __________.

(Water, Carbon dioxide, Carbohydrate)

40. The two chromatics of each chromosome are held together at __________.

(Centromere, Centrosome, Chiasma)

41. The sex-linked character in man is __________.

(Hieght, Colour-blindness, Colour of skin)

42. A bacterial cell divides by __________.

(Mitosis, Amitosis, Meiosis)

43. Gene pool is the sum total of __________.

(Genes, Gene frequency, Gene in population)

44. Karyokinesis is the division of __________.

(Nucleus, Cytoplasm, Vacuole)

45. The cell wall is __________.

(Permeable, Impermeable, Semipermeable)

46. The opening and closing of stomata are controlled by __________.

(Stomatal cells, Guard cells, Zylem Cells)

47. The physical process in which water is sucked up by a certain dry or semi-dry material is __________.

(Diffusion, Imbibition, Osmosis, Plasmolysis)

48. Inheritance and variation in living things is explained by __________.

(Ecology, Genetics, Taxonomy, Anatomy)

49. The relative time of day and night to which plant is exposed is __________.

(Photophosphorylation, Phototaxis, Photoperiodism, Phototropism)

50. In meiosis, the snapsis of homologous chromosomes takes place at this sub stage __________.

(Pachytene, Zygotene, Leptotene, Diplotene)

51. The human blood genetic disease in which the red blood cells become of abnormal shape is called __________.

(Anemia, Pneumonia, Insomnia, Sickle-cell anemia)