The study of different aspects or appearance of plants in different seasons of the year is called
a)	Ecology	b)	Ecosystem	c)	Phenology	d)	Demography

(c)

A calendar year plant shows the period of active vegetative, growth, flowering, fruiting, senescence and dormancy. The different aspects or appearances of plants in different seasons of year is called phenology. They are controlled not only by seasons and other environmental factors, but also by metabolism, heredity, and internal signals