I believe it's the body area examination, since a 'back' isn't and organ
Hope this helpss
Answer:
All of the answer options are correct.
Explanation:
Chargaff contributed in understanding the structure and composition of DNA with his discoveries. He discovered that purine and pyrimidine bases are in equal amounts in a DNA molecule. He also discovered that amount of Adenine base (A) is equal to amount of Thymine base (T). It means that A pairs with T. Since A is a purine and T is a pyrimidine it also implies that purine base pairs with a pyrimidine base. This conclusion can also be arrived by taking in consideration the other base pair which is G (purine) and C (pyrimidine).
"C. Organisms' characteristics are carried
<span> on DNA.</span>" would be the best fit, although this still isn't really the core idea behind natural selection, which is that animals survive based on how "fit" they are for their environment.