prevents backflow into the left atrium
The answer is blind impulse. This means the sudden and uncountable desire to do something. In the novel, Finny and gene have been each other's double from the beginning of the novel. Gene says to Finny the he would never have been good in the war, since he would have been willing to play basket ball with the foe instead of fighting. This brought Finny in to tears, and asks if Gene's part in the fall was just "blind impulse" and not a deliberate expression of hate.
The statement which is false about the intergumentary system is option D. "Keratin is the pigment responsible for skin color."
Even though the skin color of human beings is affected y different substances, the pigment melanin is responsible for it. Melanin is produced within the skin in cells known as melanocytes and it determines of the skin color of darker-skinned humans.
For instance, the skin color of those who have light skin is determined primary by the bluish-white connective tissue placed beneath the dermis and by the hemoglobin which circulates in the veins of the dermis.
