You are making a three-dimensional model of an extinct plant describe some use and limitations of your model

answer is a

explanation:

cell regulation is conducted by special proteins.

explanation:

the sun shines white and black light to our planet. the white light has all the colors in it. in our upper atmosphere, we have dust particles and oxygen molecules. the white light meaning all of the colors in a rainbow shines through the upper levels of the atmopshere and the blue light scatters across the entire planet. that is why our sky is blue.