Question 10. Which two of the following may pass through the placenta and harm the embryo?
a. Bacteria and Fungi
b. Drugs and Bacteria
c. Viruses and Fungi
d. Viruses and Drugs

The circles, or orbits, for electrons are called energy levels. each level can hold only a certain number of electrons. add electrons to each level until you can't add any more. how many electrons can each level hold?

State officials are considering constructing a road through a forested wilderness area. this action will likely affect the forest ecosystem in various ways. part a: predict how the construction of a road could negatively affect plants and animals in that ecosystem. (3 points) part b: describe one way that the construction of a road could have a positive impact of the forest ecosystem. (1 point)

Which event would lead to primary succession of a forest?