Depression that repeatedly occurs with onset of autumn and winter is to as chronic, low-grade depression is to seasonal affective disorder; dysthymic disorder cyclothymic disorder; seasonal affective disorder bipolar disorder; cyclothymic disorder rapid cycling; flat affect

Depression that repeatedly occurs with the onset of autumn and winter is to seasonal affective disorder as chronic, low -grade depression is to dysthymic disorder. Seasonal affective disorder is a type of depression that is related to changes in seasons such that it begins and ends at about the same times every year. Dysthymic disorder is a smoldering mood disturbance characterized by a long duration as well as transient periods of normal blood. 

Carbon cycle may be defined as a type of biogeochemical cycle that regulates the amount of carbon in nature. The carbon is released by the living animals and utilized by the plants in form of carbon dioxide.  

Respiration and photosynthesis are the two major parts of the carbon cycle. Respiration produces

C

O

2

carbon dioxide. Photosynthesis takes

C

O

2

out of the atmosphere.

Explanation: