1. which phylum contains clams, snails, and slugs? a) chondrichthyes b) mammalia c) mollusca d) cnidaria 2. which phylum contains sea anemones, coral, and jellyfish? a) mollusca b) cnidaria c) porifera d) arthropoda 3. according to the 10% rule, it is healthiest to a) the highest trophic levels. b) the lowest trophic levels. c) from all the trophic levels. d) there are different healthy things to eat from any level, so it depends. 4. which of the following shows the three stages of ecological succession in the correct order? a) climax community, pioneer species, perennials b) pioneer species, perennials, climax community c) perennials, climax community, pioneer species d) pioneer species, climax community, perennials 5. which of the following is not a reason that coral reefs are important? a) they contain a high diversity of organisms. b) they serve as a barrier to storm surges that cause damage on land. c) they block predatory fish from coming near shore. d) they sustains fishing industries and tourism in many countries. 6. why do some plants have nodules on their roots? a) they are diseased from a lack of nitrogen. b) nitrogen-fixing bacteria live inside them in a symbiotic relationship. c) nitrogen-fixing bacteria live inside them in a parasitic relationship. d) none of the above are true. 7. why is the term global warming often used when referring to climate change? a) every location on earth is hotter every year than the year before. b) the sea temperatures have increased by 20 degrees. c) on average, the overall trend for the earth's surface temperature is increasing. d) none of the above are true. 8. which of the following technologies is the most likely to stretch the earth's carrying capacity? a) an axe b) a fishing rod and reel c) a bulldozer d) a h. o.e