1) nematodes exhibit the constant cell number called? 2) a certain species of roundworm can live inside human lymph nodes and cause severe swelling in the limbs, a condition known as (a) lymphitis (b) diabetes (c) gangrene (d) elephantiasis (3) which of the following statements is about nematodes is false? (a) some consume dead plant matter (b) they can be parasitic (c) they lack a body cavity (4) all of the following are characteristics shared by both flatworms and roundworms, except (a) bilateral symmetry (b) cephalization (c) digestive tract with both mouth and anus

Ascientist is investigating the effects of salinity on fish development. he places fertilized fish eggs in an aquarium that contains low salinity and observes their development. what factor would improve experimental design the most? place the fish eggs in the open ocean because that is the natural habitat include another aquarium that has normal salinity to compare to the low salinity aquarium include an aquarium that replaces salt with sugar to confirm that the effects are specific to salt grow algae with the fish eggs in order to provide adequate nutrients to the developing embryos