What is the function of the enzymes helicases in dna replication?

How are mutations continually being generated in a population (what are some of the causes of mutatuions? ) explain

Below, the levels of organization in a multicellular organism are shown from least to most complex. which level of organization can be described as several different types of tissues working together to perform a common task?

Asap. this question is 100 points if you answer it question: describe the basic relationship between ocean depth and temperature seen in the graph