What are molecular clocks used for A- to cure hereditary disease
B- to classify
C- to locate fossils under water
D- to compare homologous structures

i think it would be b. tissue because an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.

a "theory" a suggestion that is not 100 % accurate, or a figure. some people say its a theory because they of all the passed theory's about one subject. it depends sometimes theory might be accurate and sometimes they are.

because they are eaten by the frog and the frog getseaten by the snake and the snake by the eagle

i got you i did it ya know what it is just needing to fill this in for a quick task!