Answer:
By definition, tissues are absent from unicellular organisms. Even among the simplest multicellular species, such as sponges, tissues are lacking or are poorly differentiated. But multicellular animals and plants that are more advanced have specialized tissues that can organize and regulate an organism’s response to its environment.
Answer:
Peristalsis is a series of wave-like muscle contractions that move food through the digestive tract. ... There, the food is churned into a liquid mixture called chyme that moves into the small intestine where peristalsis continues. Stretching out a piece of intestine will make it easier to see the wave-like motion
The answer to this question would be Fermentation. This is a process that releases energy when oxygen is insufficient.