Answer:
(a) Ecosystem, community, population, individual
is right answer I think
Some spicules are formed of the mineralized substances calcium carbonate and silica, while others are made of an organic substance called spongin. Sponginskeletons<span> were and are used as scrubbers in bathtubs, though they are fairly expensive. The ubiquitous bathtub accessory called a lufa is NOT a </span>sponge<span>, but a plant.</span>
Answer:
It is affected by the concentration gradient.
Diffusion stops, when the concentrations of the substance on either side of the barrier become equal.
Explanation:
