What is the significance of chitin in arthropods?

In a cladogram, what occurs at a node? a derived trait appears. evolution is stopped. an ancestor dies. the cladogram ends. aa as s as ss what are the chances that their offspring will have sickle cell anemia? 0% 25% 50% 100%

Which of the following types of pollution is most responsible for large numbers of deaths worldwide because of unsafe drinking water? (a) nutrient pollution (b) thermal pollution (c) pathogen pollution (d) sediment pollution

Make a claim about the factors that cause inherited genetic variations within populations. also make a claim about the effects of mutations.