"In a particular case of secondary succession, three species of wild grass all invaded a field. By the second season, a single species dominated the field. A possible factor in this secondary succession was ."

A possible factor for the above is best described by the inhibition model. This is a model of succession that allows for early colonizers to modify their environment making it only conducive for them hence ensuring their survival. If this is done successfully, by the second season, of the the 3 species of  wild grass, only one will thrive in the field as a result of the phasing out of the other 2.

Explanation:

The inhibition model occurs as a result of the environment being modified by of the 3 species of wild grass by the 2nd season. This may have been as a result of it secreting biotoxins into the environment that destroys the other 2 wild grass, thus inhibiting their growth. This helps the organism thrive well during the 2nd season  

osteogenesis imperfecta (oi) refers to a congenital ailment of bones. in the condition, the bones become brittle or fragile. this ailment is a general result of the defect or mutations in the genes (colia1 or colia2). this mutation results in imperfect collagen formation either in quantity or quality wise.  

there are eight kinds of oi defects, and each kind varies with certain distinctions in symptoms. the usual symptoms include frequent bone fractures, loss of hearing in infants, protruding eyes, discoloration of the white in the eyes, respiratory issues, loosening of the joints, short stature, and other symptoms.