ECM is the extracellular matrix, or the set of extracellular molecules secreted by cells with the purpose to support surrounding cells. In plants the cell wall is the ECM and in mammals ECM can be in the form of fibrils and may constitute a significant portion of the bulk of the organism and it also referred as connective tissue.
The correct answer is; the open mouth of a baby robin is seen as a sign stimulus for the female robin (parent), and that the open mouth is the impending cause for her behavior.
Precipitation<span> is </span>water<span> released from clouds in the form of rain, freezing rain, sleet, snow, or hail.</span>
For the first blank, it's cell membrane and the other blank is transport.
Biology is the study of life.