Active transport is the moving of molecules across the membrane of the cell against the concentration gradient with the use of ATP.
Low to high concentration. Concentration gradient is the diffusion (movement of molecules from regions of low concentration) from high to low with the gradient. Active transport is from low to high, against the gradient.
They all develop gills, slits and tails
The answer is C: What is the cause of cancer in mice
I believe animals that possess homologous structures probably evolved from the same ancestor. Homologous structures are similar because of common ancestry. A homologous structure is an example of an organ or bone that appears in different animals, underlining anatomical commonalities demonstrating descent from a common ancestor.