I thinking the answer was for some genes, both alleles express together. Others combine to give an average phenotype....
I believe the blank is "mass."
Answer: It was obtained 8515 years ago
Explanation:
Expression for rate law for first order kinetics is given by:

where,
k = rate constant
t = age of sample
a = let initial amount of the reactant
a - x = amount left after decay process
a) to find the rate constant:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.


b) for completion of 36% of reaction


t = 8515 years
The time was 8515 years.
Harmful because they change how the genes are supposed to form and they can give disorders at times.