Unlike nonsteroid hormones, steroid hormones a. bind to receptors on the outside of cell membranes. b. enter the nucleus and change gene expression in a target cell. c. include proteins and modified amino acids. d. can't pass through cell membranes.

80 pts the type of cloud shown here may produce heavy rainfall. this type of cloud most likely occurs in an area of the sub-saharan that is a) often dry. b) often wet. c) very windy. d) usually cool.

Explain why phospholipid molecules form a bilayer. (3 marks)

And give a detailed description! scientist observes the boundary between two tectonic plates for a decade and finds that no new volcanoes have formed over the course of her investigation. does this result support the theory of plate tectonics? why or why not?