Eukaryotic cells differ from each other due to their structure and function. Though, two eukaryotic cells could differ in the number and types of organelles they contain.
The fruit flys population would be less since the apples isn’t there anymore. The reasoning behind that is because it’s a fruit fly they like being around fruit.
Go to the Prenatal Testing page for more details. If one parent has sickle cell trait (HbAS) and the other has sickle cell anaemia (HbSS) there is a one in two(50%) chance that any given child will get sickle cell trait and a one in two chance that any given child will get sickle cell anaemia.