Shell size and shape in a species of snail varies, with two shapes being most common: thin walled with a pointed spire, and thick walled with a low, rounded spire. If a species of crab that eats snails by crushing their shells moves into an area with roughly equal numbers of snails with the two shell shapes, what do you predict will happen over the course of the next 50 generations of snails

What is the name of the two satelites on mars

Duchenne muscular dystrophy is a serious condition caused by a recessive allele of a gene on the human x chromosome. the patients have muscles that weaken over time because they have absent or decreased dystrophin, a muscle protein. they rarely live past their twenties. how likely is it for a woman to have this condition? a) women can never have this condition. b) one-fourth of the daughters of an affected man would have this condition. c) one-half of the daughters of an affected father and a carrier mother could have this condition. d) only if a woman is xxx could she have this condition.

In an experiment examining the effects tai chi on arthritis pain, callahan (2010) selected a large sample of individuals with doctor-diagnosed arthritis. half of the participants immediately began a tai chi course and the other half (the control group) waited 8 weeks before beginning. at the end of 8 weeks, the individuals who had experienced tai chi had less arthritis pain that those who had not participated in the course.