The answer to this is A because groups of cells do form tissues.
Explanation:
Receptors are specific molecular components of a biological system with which drugs interact to produce changes in body function. This fundamental event of drug-receptor interaction initiates communication, through signal molecules (first messenger) of great structural and functional diversity, with receptors coupled to ionic channels, to G-proteins, catalytic or regulators of DNA transcription, as well as The integrated support of second messengers. It also mentions certain diseases that arise due to dysfunction of these receptors of the receptor-effector systems, such as the appearance of aberrant receptors or as products of "oncogenes".
Answer:
Friend (endotherm) will need to eat more calories than snake (ectoderm) to maintain constant body temperature.
To generate heat endotherms convert the food they eat into energy through the process called metabolism. Most of the food that the endotherms eat is converted into fuel to maintain a constant body temperature. Endotherms need to eat more food than ectoderms of the same size to maintain their constant body temperature.
Explanation: