What is positive feedback? what is negative feedback? biology wise

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?

Invasive species are one of the major threats to biodiversity. these species multiply quickly and compete with native species for food, sunlight, spac and other resources. on the map, determine the area where native species will have limited resources available to them due to invasion threat from invasive species threat very low low medium high very high

Explain why biological control methods are generally environmentally superior to chemical pest control methods.