Answer:
D
It helps the reader to understand which layers of the atmosphere are most important. Don't cheat
As you can see from the image presented below when parents with AB Ss and AA ss genotypes cross we get three distinct phenotype groups.
Marked in red are the individuals whose A type blood we can determine from the saliva because they have at least one S allele.
Marked in light green are the individuals whose AB type of blood we can determine from the saliva too.
And marked in orange are the individuals that are homozygous recessive for the s allele, and we could not determine their blood type from their saliva.
Answer:
The physical stimulus is the only part of the test that is measureable, and therefore, knowable. The stimulus is our anchor for our estimate of the listener's perception.
A model organism is a species that has been widely studied to understand a particular biological phenomena, normally used because they are easy to breed and maintain in a laboratory setting and has certain experimental advantage.
The criteria that Thomas hunt Morgan was looking for include; the model organism should be small in size, easy to keep in the laboratory and also able to produce large number of off springs in a short time.