51.
Mycorrhiza represents

52.
Which of the following interactions will not promote co evolution?

53.
Earth summit was held in

54.
The unit of measurement of intensity of sound is in _________

55.
Which of the following spatial units is the largest in terms of scale?

56.
Natural earthquakes are caused by __________

57.
Eutrophication results from

58.
Organisms that feed upon other living organisms as a source of energy and nutrients are called as

59.
Nuclear accidents mostly release radioactive __________ into the atmosphere

60.
The presence of which is necessary for photosynthesis