What are small fishlike animals that live in the sandy shallow bottoms of the ocean and feed by filtering food through their gill slits?

Although there are a limited number of amino acids many different types of proteins exist because..

Color blindness is a recessive trait. the gene for color blindness is on the x chromosome. the family tree below shows the trait of color blindness. the only unknown is the mother in the first generation

What element does susan b. anthony include in this passage to strengthen her argument?