They can distinguish whether the entity is living or non living by checking whether they have all the seven characteristics of living things.
These 7 characteristics include:
Movement
Respiration
Sensitivity
Growth
Reproduction
Excretion
Nutrition.
If the entity does show all these seven characteristics, it should be a living organism.
In the past, scientists by using these 7 characteristics, they sorted living things in 5 kingdoms(plus virus), each with their own other characteristics.
30. Sex cells are always haploid, meaning they have half the number of chromosomes.
The stomach is a muscular organ located on the left side of the upper abdomen. The stomach receives food from the esophagus. The stomach is the first stop in the digestive tract before food moves on to the small intestine. <span>It secretes digestive enzymes and gastric acid to aid in food digestion. </span>
That would be the <span>NUCLEOLUS</span>
