Why does meiosis produce cells with half the chromosomes

What do animals wth echolocation have in common other than echolocation

Ausable water source is one that can be used by humans for drinking or agriculture. identify the water reservoirs as usable or unusable based on their current state. oceans rivers glaciers freshwater lakes groundwater

Parasitism could be considered a form of which of these types of relationships? -mutualism -commensalism -predator-prey -mimicry