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.
Answer: Term Meaning
Monomer A molecule that is a building block for larger molecules (polymers). For example, an amino acid acts as the building blocks for proteins.
Polymer A large molecule made of repeating subunits (monomers). For example, a carbohydrate is a polymer that is made of repeating monosaccharides.
Explanation:
Answer:
The pumping action of the heart propels the blood into the arteries, from an area of higher pressure toward an area of lower pressure. If blood is to flow from the veins back into the heart, the pressure in the veins must be greater than the pressure in the atria of the heart.
The correct answer is - A strong wind blows across a Midwestern prairies.
An energy flow through a natural system is when we have no human interference or any man made objects in the process. A strong wind that blows across a Midwestern prairie is a nice example of this. We have a natural unmodified by humans environment through which a natural phenomenon is bringing energy flow. The energy flow will of course operate in different manner and have different effects compared to the ways in which the humans would have used it. The strong wind in the prairie will bring in lot of small particles, sediments, with its energy and deposit big portion of them in the prairie, thus making it more fertile.