What are the significance of helicase enzymes during dna replication?

You need to make 500ml of 7h9(+) media with 1x adn and 30ug/ml of the antibiotic kanamycin. your stock solutions are 10x adn and 30mg/ml of kanamycin. the solvent is distilled water. how much of each component will you need to make the desired final solution?

Scientists discover two populations of mice on either side of a major river. the two populations have almost identical genes but the mice from one side cannot breed with mice from the other. this is most likely because

Polar zones are cold and tend to be dry because of a pressure system of cold. low high