BT403 Final Term MCQs

BT 403 · M.C.Q Final Term · Lecture 57 to 100

1. ________ the herbicide is physically removed from the target site. Sequestration
2. ____ is a change in the binding site that prevents the herbicide from binding or interacting. Target-site mutation
3. Which one of the following is the most common mechanism of herbicide resistance? Altered target site
4. Metabolism within the plant is one mechanism a plant uses to detoxify a foreign compound such as an herbicide.
5. ___________ effective against 76 of world’s worst 78 weeds. Glyphosate
6. Shikimic acid pathway results in the formation of__________ amino acids, phenols and metabolites.
7. Shikimic acid pathway doesn't occur in_____________ Animals
8. The transgenic plants can tolerate glyphosphate 2 -4 times higher than that required to kill wild type weed plants.
9. EPSPS mutant gene resistant to glyphosphate was found in s. typhimurium it was found that single base substitution (C to T) change in amino acid from proline to serine.
10. The part of plant cell where shikimic acid Pathway occurs? Chloroplast
11. The soil microorganism posses’ enzymes glyphosphate oxidase that converts to glyphosate to glyoxylate.
12. How many type of herbicides resistance? Four
13. NCWSS stands for ______________ The North Central Weed Science Society
14. Respond quickly to changes in weed populations to restrict spread of weeds that may have been selected for

resistance. Scout fields

15. ___________ is an external factor that exerts a disadvantageous influence on the plant. Stress
16. How many types of water stress? Two
17. Stomata closure, reduced ___________ supply and slower the rate of biochemical reactions during prolonged periods of dehydration. Carbon dioxide
18. __________ has high level flooding tolerance. FR13A rice-type
19. In response to high temperature all organisms, including plants, synthesize a set of proteins called as ________

heat shock proteins

20. ______ causes protoplast volume shrinkage upon extra-cellular ice formation. Chilling
21. About 50% of crop yield in Pakistan is affected by the wind stress.
22. Wounds or wilting caused by winds give sites for the_________ virus or bacterial infections.
23. All carbohydrates, fatty acids and protein content were adversely affected due to_________ salinity effect.
24. Salt stress induces the synthesis of Abscisic acid which closes stomata when transported to guard cells.
25. The accumulation of Na+ and Cl- ions in the cells is very toxic in terms that these ions can influence the enzymatic action.
26. Which metal is required for the all kinds of plant for photosynthesis? Copper (Cu)
27. ______ may be defined as the series of invisible and visible responses of plant cells or tissues to a pathogenic microorganism. Plant Disease
28. Which is the infectious component of a virus? Nucleic Acid
29. Which one of the following is amongst the microbes which benefit as well as harm the plants? Bacteria
30. ____________ disease is marked by the chlorosis of different plant tissues. Blight Disease
31. Which bacteria that causes fire blight? Erwinia amylovora
32. Which chemical is used to prevent the fire blight? Terramycin
33. Brown Spot Disease is caused by the bacteria named? Pseudomonas synringae
34. Crown gall disease is caused by the _____________ Agrobacterium tumefaciens
35. Fungi the cause of about ____________ percent of all plant diseases. Eighty-five
36. Fungi do not have ___________ and cannot photosynthesize. Chlorophyll
37. BROWN PATCH is a turfgrass disease caused by different species of the Rhizoctonia fungus.
38. Water & mineral absorption is also reduced by some vascular pathogen that inhibits root hair formation.
39. ____ is one of the most common symptoms of plant disease and refers to the destruction or inhibition of chlorophyll. Chlorosis
40. The enzyme chlorophyllase secreted after disease infection in leaves that causes conversion of chlorophyll to

________ chlorophyllide and phytol

41. Calvin cycle is progressively reduced due to changes in the concentration of ____________ carbohydrates
42. The rate of respiration increase in diseased plants is brought about by uncoupling electron transfer from oxidative phosphorylation of ADP to generate ____________ ATP
43. Synthesis of some novel proteins have been reported during infection in resistant plant varieties called pathogenesis-related protein.
44. Plants exhibit certain _______ defense response against biotic stresses. Physical and chemical
45. _______ is outgrowths of the protoplast of adjacent parenchymatous cells protruded into xylem vessels. Tyloses
46. Which is involved in inhibit further pathogen penetration within the host? Swelling
47. _____ are consist of one or more benzene ring with one or more hydroxyl groups. Phenolics
48. ________ the main inhibitory compounds synthesized by the plant cells in response to the infection. Phenolics
49. Pathogen attack strategies in which the plant cells are killed are called _______ Necrotrophy
50. Pathogen attack strategies in which the plant cells are remain live are called _______ Biotrophy
51. In Hypersensitivity response the 1st line of activated defense is within ________ 24 Hours
52. ROS stands for____________ Reactive Oxygen species
53. ________ maybe directly toxic to pathogens. H2O2
54. _____ is known to bind heme and could inhibit catalase and ascorbate peroxidase, which detoxifies H2O2. NO
55. Which is required to mediate both resistances against necrotrophic fungal pathogens? Ethylene
56. Biotic and abiotic stresses can reduce average plant productivity by ___ depending on the crop. 65% to 87%
57. Loss of productivity due to diseases range from___________ 20 to 30 %
58. Loss of productivity due to insects pest range from___________ 10 to 20%
59. Resistance or sensitivity of plants to stress depends on________ Species, Genotype and development age
60. ________ non heritable physiological and biochemical gene expression. Acclimation
61. A stress response is initiated when plants recognizes stress at the ___________ cellular level
62. Oxidative stress results from conditions promoting the formation of active oxygen species that damage or kill cells.