Symbiosis

Have students mark each species in a pair as helped, harmed or not affected before they sort it. On the graph sheet, remind students to read hares on the left axis and lynx on the right axis.

Sort nine species pairs such as remora and shark into mutualism, commensalism and parasitism. The directions on the page read: Read the text and study the chart. Then complete page 2. An answer key is included.

Yes, both. We made it for 6th Grade ecosystems, and the page works the same whether it lands on a kitchen table or a center rotation. At home, most families go through it together and talk the answers out loud, and that talking is where most of the learning happens with symbiosis and predators. In class it runs well as independent work while you pull a small group. Print one copy or thirty, whichever the day needs.

In mutualism both species benefit. On the Symbiosis sheet, a bee gets nectar and the flower's pollen gets spread, and an oxpecker eats ticks on a rhino so the rhino loses its pests.

Look at each species separately and ask whether it is helped, harmed or not affected. In commensalism the other species is not affected, as with a remora and a shark. In parasitism it is harmed, as with a tapeworm and a dog.

When hares are plentiful, well-fed lynx raise more young, but the young take time to grow. On the model graph in Predator and Prey Populations, each lynx peak comes 2 years after a hare peak.