Two fruit flies that are heterozygous for body color and eye color are crossed. Brown body color is dominant to black body color
. Red eye color is dominant to brown eye color. Use the Punnett square to determine the ratio of offspring with: Brown body and red eyes : Brown body and brown eyes : Black body and red eyes : Black body and brown eyes :
In a double cross of two heterozygotes for both traits ( BrBl Rbx BrBl Rb) we would get a <span>9:3:3:1 phenotypic ratio. 9 Brown body, red eyes (both dominant traits) 3 brown body, brown eyes (one dominant, one recessive trait) 3 black body, red eyes ( one recessive and one dominant trait) 1 black body, brown eyes ( both recessive traits)</span>
"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.
