What type of graph displays the frequencies of events or traits

How many trophic levels are there in the following food chain? phytoplankton - shrimp - perch - pike - osprey

Johannesburg kepler, an apprentice of brahe, believed in the heliocentric universe but rejected past astronomers belief in

Which is a genetic engineering advancement directly related to a career in biotechnology? 1) improving solar energy collection 2) transporting textiles at higher rates 3)creating crop foods that resist insect pests 4)repairing historical sites with quality materials