Final answer:
In multicellular organisms, signals can be classified as visual, auditory, tactile, or olfactory based on their mode of delivery, with specific sensory systems dedicated to the reception and processing of these signals. Intracellular signals include autocrine, paracrine, endocrine, and direct signaling across gap junctions, differentiated by the distance of signal travel to target cells.
Step-by-step explanation:
Different types of signals based on their sources/mode of delivery in the context of communication in multicellular organisms include visual, auditory, tactile, and olfactory signals. For example, visual signals involve the activation of photoreceptors, while auditory signals are transmitted over their own dedicated system and are interpreted by the brain as sounds. Tactile signals include sensations such as pressure, vibration, and pain, which are sensed by mechanoreceptors. Lastly, olfactory signals are related to smell and involve the chemical senses.
Intracellular signaling can be further categorized into autocrine, paracrine, endocrine signaling, and direct signaling across gap junctions. The main difference between these types of signaling is the distance that the signal travels to reach the target cell. Not all cells are affected by the same signals, as the specificity of the signals allows for diverse responses.