Fish are thought to have descended from ostracoderms.

In a emergency atp synthase can pump in which direction for a limited amount of time

Which of the following is NOT considered part of the body's nonspecific lines of defense against disease? A) antibodiesB) mucous membranesC) intact skinD) bloodborne chemicalsE) phagocytic cells

A hypothesis can be disproved by a single experiment true or false

Milk has a pH of 6. Tomato juice has a pH of 4. Therefore, tomato juice is: A. 20 times more acidic than milk. B. 100 times more acidic than milk. C. 100 times less acidic than milk. D. 20 times less acidic than milk

Prokaryotic cells and eukaryotic cells are similar in all of these aspects except: A. their ability to maintain homeostasis B. their average size C. their cell membrane D. the macromolecules they contain

Which structure type is not formed by polymers? A) crystalline B) 1-dimensional chain C) 2-dimensional sheet D) 3-dimensional framework

How does a birds sternum compare to yours? What is another name for it?

Why is it unlikely that the frequency of muscular dystrophy in the human population will be reduced quickly by means of natural selection?

Adaptations give organisms a better chance for

Sound waves cannot travel in a cacuum because?