A certain species of trilobite is known to have lived 300 million years ago. If this index fossil was found in a rock layer containing other fossils, what could you infer about the other fossils a The rock layer killed the trilobite and the other fossils
b The other fossils are about 300 million years old
c The organisms that formed the other fossils are still living.
d The rock layer formed before the trilobite and other organisms

b The other fossils are about 300 million years old

Explanation:

From the description of the problem given, we can correctly conclude that the other fossils are about 300 million years old and even the rock layers formed around that period in time too.

Fossils are the preserved remains of organisms that has once lived. Through the principle of relative dating we can determine the age of fossils and those of other related ones. According to the principle of fossil and fauna succession, "fossils succeed one another in a predetermined form". So, the fossils occurring together within the rock layers are of the same age.

The soviet union beat the us to the first successful launch, with the october 4, 1957, orbiting of sputnik 1, and later beat the us to have the first human in earth orbit, yuri gagarin, on april 12, 1961. the "race" peaked with the july 20, 1969, us landing of the first humans on the moon with apollo 11

The answer would be c, white eyes are homozygous recessive. in the early 1900s, morgan conducted several experiments with vinegar  flies (drosophila). one  sample revealed an anomaly: a  white-eyed, single male fly. he attempted to breed this fly with the typical red-eyed females. the offspring were all red-eyed. using flies from this new generation (brother-sister pairs)  produced some red-eyed and a few white-eyed flies. the white-eyed were all male. in later experiments, he was able to produce white-eyed females. this proved that white eyes are not lethal to either sex (ruling out a and b). since the percentage of white eyes to red eyes is so low, white eyes are not a dominant trait. it would be a recessive trait.