I think the hydra lacks the specialized cells for touch and chemical detection. On the other hand earthworms have touch, light, vibration and chemical receptors along the entire body surface. Both of them are invertebrates (those animals without a backbone), they include insects, worms, jelly fish, spiders among other animals.
A difference between plant cells and animal cells is that most animal cells are round whereas most plant cells are rectangular.Plant cells have a rigid cell wall that surrounds the cell membrane. Animal cells do not have a cell wall. When looking under a microscope, the cell wall is an easy way to distinguish plant cells.
Difference Between Plant And Animal Cells 1 Chloroplast. Like animal cells plant cells have mitochondria. 2 Cell Wall. Animal cells do not contain a cell wall while plant cells and fungi cells do. 3 Vacuole. Vacuoles are very large membrane-bound sacs within plant cells.
