Rays obtain oxygen rich water through . a.
their mouths
c.
moving to pass water over their gills
b.
small holes in their heads
d.
swimming to shallow water

The probability of producing a normal child by two parents who are carriers for an autosomal recessive disorder is

Some birds look for food near cattle and other livestock. the movement of the cattle churns up the ground, making insects available to the birds. the cattle appear to be unaffected by the presence of the birds. what kind of relationship exists between the birds and the cattle? o a. parasitism o b. commensalism o c. predation o d. mutualism

Where in the cell are ribosomes made?