Frogs are insectivores. If the frogs prey on the gnats and their numbers are decreased, this allows the gnats to proliferate because the competition for survival is lessened. Gnats, being lower on the food chain, have adapted to lay large numbers of eggs due to the environmental pressures under which they evolved (being eaten in large quantities). Therefore, fewer gnats being eaten = more gnats surviving.
The top row definitly pretty obvious
It surrounds the cell membrane and provides cells with structural protection and support. It also helps filter.
