The ability of certain specifically shaped molecules to attach to a cell is primarily determined by the... 1. Receptor molecules in the cell membrane

2. Amount of DNA in a cell

3. The cytoplasm of the cell

4. Concentration of salts outside the cell

The embryos of a bird, a reptile, and a mammal are similar in appearance. how does comparing the physical appearance of embryos of different species support the theory of evolution? a. it shows that these organisms share a common ancestor. b. it provides evidence that these organisms eat the same foods. c. it shows that these organisms share the same habitat. d. it provides evidence that these organisms suffered a genetic mutation.