Molecules that are not able to independently diffuse across a membrane may still move down their concentration gradient by

The higher you go up the less oxygen there is 

The main role of dna in the  cell is the long-term storage of information. it is often compared to a blueprint, since it contains the instructions to construct other components of the  cell, such as  proteins  and rna molecules.the main function of rna is to carry information of amino acid sequence from the genes to where  proteins  are assembled on  ribosomes  in the  cytoplasm. mark brainliest, my work is good.

The name of the instrument that the scientist uses is called a microscope.a microscope is used to view objects which is not visible to the naked eyes