Answer:
This statement is true, as the inner core is the most dense layer of the earth.
<span>b. more like other protists than members of other kingdoms.</span>
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.