This activity is a good warm-up exercise for early in the school year for biology classes. It can be modified for any age group and ability level.
Students work in groups, which allows them to get to know each other and you can talk to them in those groups and get to know them as well. I usually set the groups up beforehand, or have them draw cards as they enter the classroom. Getting into groups, on the first day, can cause anxiety for kids that are new and don't know other kids (or for those who are shy.)
Each group will pick a topic at random - I place them on slips of paper and students drawn them. Their goal is to create a type of KWL chart for each topic. if you hand out the slips as students enter the class, the first task can be to find the other members of their group.
Global Warming (Climate Change)