They look at it under a microscope and see if it has cells. Basically, if it has cells the it's alive. If it doesn't have cells it is considered nonliving. There are smaller archaebacteria that behave like small parts of cells. These are considered living too, because they have chemical bonds of RNA, which is the singular shorter form of DNA. There is evidence that viruses change with different hosts, but they are generally considered non-living. They are much smaller chemical chains (with some form of movement and reproduction) and do not come from cells through reproduction. They come from cells by 'hijacking' normal cells and inserting their small chemical chains into the cells' DNA or RNA. The cells and all its organic machines change to function like the virus and eventually collapse to spread the virus. If that's living, it sure beats staying inside typing so many hours with a cold.
Viruses are not complex enough to really change their movements or transmissions. They are like cancer in that they are cellular malfunctions, except they transmit to other hosts. They do change slightly, but biologists do not qualify this change as a property of life: they just look for cells.
Biologists determine whether a thing is living or nonliving by a list of characteristics. These characteristics include the ability to reproduce, the ability to eat, the ability to grow and the ability to excrete waste.
A living object has certain characteristics that a nonliving object does not possess.
You can tell because it will show characteristics of a living or nonliving object.
Marine biologist can studie everything from alage to the largest animal in the ocean.
There is some debate about the status of a virus, whether it is living, not living, or some intermediary condition.
Marine biologist's study everything from algae to the largest whale. Basically anything in the ocean, living or not they will study.
NOnliving, biotic is living
The sky is nonliving
A waterfall is nonliving because water is not a living thing.
Sand, soil, rocks, gravel, water, air and light are abiotic (nonliving) factors of the desert. All living creatures, whether plant or animal, are biotic (living) factors.
it is nonliving
No, it is not size that determines whether a cell is dead or living, merely whether it is alive or not. Regardless of size, they are all living.
Any living thing, or anything (that is realitively young) will have carbon-14 decomposition in it.
It is Nonliving