Which allele combination represents a female who is a carrier for an X-linked recessive disorder? XRXr
XrXr
XRY
XrY

What is the primary goal of human communities?

In iceland, the mid atlantic ridge runs through the center of the contry. what can you conclude about the apperence of iceland many thousands of years from now?

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?