The skin acts as a physical barrier and prevents foreign substances entering the body. In which system is the skin playing a role by performing this function?

Out of 5 undisturbed horizontal beds of sedimentary rock, we can say that A. the top layer is oldest B. the lowest layer is oldest C. there is no way of knowing which is oldest D. the 2nd and 3rd are younger than the top layer.

Since dinosaurs cannot swim how can a fossil be found on all continents

Environment determines the types of leaves that can grow in an area. Which type of leaf adaptations would you expect in a hot and dry climate such as a desert? thin and spiral leaves with stoma on the topside large and broad leaves thick and waxy

Why would the majority of ocean life by found in shallow water, instead of deep water?

A scientist wants to determine the effect of a new type of gasoline. He fills e car with normal gasoline and another identical car with the new gasoline. Which is the control group?

The dental formula 2-1-2-3 corresponds to what order of teeth? a. molars, premolars, canines, incisors b. incisors, canines, premolars, molars c. canines, premolars, incisors, molars d. premolars, molars, incisors, canines

What occurs when bonds are broken and new bonds are formed

Name one negative consequence of . exponential human population growth.

Fluorine has seven electrons in its outer energy level. According to the octet rule,

Where in the plant cell do the light reactions and dark reactions occur repeatedly?