Agood model of the cell membrane would be

Two pieces of cardboard one located at the bottom and one on top joint by card board with balls at the bottom and top all joint. hope you can picture that, it's rather confusing, sorry.

Hope this helps

answer; //the above statement is (false);

c) 50% there are four chromosomes. after crossing over, 2 of the four have been changed. that means any gamete has a 2 in 4 chance or 50% chance of receiving the mutated chromosome.