In humans, a dominant allele controls the formation of a cleft chin, a Y-shaped fissure in the chin caused by an atypical bone formation in the mandible (this phenotype
is also known as a chin dimple). A survey of 1200 college students found that
108 of them did not have a cleft chin. What was the frequency of heterozygotes in
that student population?

the answer is 100% density i've answered this question before and done the quiz myself.

1. the geologists have established a set of principals that can can be used o determine the relative ages of rock. this principal is applied to sedimentary and volcanic rocks. the rocks exposed to wall of grand canyon has layers and by studying the number of horizontal layers in the rock(strata) the relative age can be determined. the layer first formed will appear at the bottom and the the layer of strata last formed appear at the top. by using this information the approximate age of rocks can be determined.

2. carbon dating is used to find the relative age of rock in numbers which means for the rocks that has age between 1-70,000 years.

3. for the rocks of age range between 1,000 - billion of years potassium-argon dating is used.