What is the source of the genetic information that determines the traits of a pacific tree frog?
a. molecules of the cell membrane
b. organisms eaten by the tadpole
c. water in the habitat of the tadpole
d. chromosomes found in the cell nucleus

The answer to the question above is letter D. Chromosomes found in the cell nucleus.
In the cell nucleus, DNA is tightly packed into the thread-like structure known as chromosomes. Every chromosome is made up of tightly coiled DNA around proteins (histones) that support its structure. Chromosomes are not visible when there is no cell division. It cannot be seen in the cell’s nucleus nor under the finest microscope. They are only visible when the cell is dividing and is apparently visible under a microscope.